Polyaniline Composite Films with Exceptional Seebeck

further developing green power.2 Thermoelectric materials composed of organic polymers are subjects of increasing attention in recent years.3-5 Becaus...
3 downloads 0 Views 665KB Size
Subscriber access provided by University of Winnipeg Library

Applications of Polymer, Composite, and Coating Materials

Zr-MOF/Polyaniline Composite Films with Exceptional Seebeck Coefficient for Thermoelectric Materials Applications Chih-Chien Lin, Yi-Chia Huang, Muhammad Usman, Wen-Hsuan Chao, Wei-Keng Lin, Tzuoo-Tsair Luo, Wha-Tzong Whang, Chun-Hua Chen, and Kuang-Lieh Lu ACS Appl. Mater. Interfaces, Just Accepted Manuscript • DOI: 10.1021/acsami.8b17308 • Publication Date (Web): 24 Dec 2018 Downloaded from http://pubs.acs.org on December 24, 2018

Just Accepted “Just Accepted” manuscripts have been peer-reviewed and accepted for publication. They are posted online prior to technical editing, formatting for publication and author proofing. The American Chemical Society provides “Just Accepted” as a service to the research community to expedite the dissemination of scientific material as soon as possible after acceptance. “Just Accepted” manuscripts appear in full in PDF format accompanied by an HTML abstract. “Just Accepted” manuscripts have been fully peer reviewed, but should not be considered the official version of record. They are citable by the Digital Object Identifier (DOI®). “Just Accepted” is an optional service offered to authors. Therefore, the “Just Accepted” Web site may not include all articles that will be published in the journal. After a manuscript is technically edited and formatted, it will be removed from the “Just Accepted” Web site and published as an ASAP article. Note that technical editing may introduce minor changes to the manuscript text and/or graphics which could affect content, and all legal disclaimers and ethical guidelines that apply to the journal pertain. ACS cannot be held responsible for errors or consequences arising from the use of information contained in these “Just Accepted” manuscripts.

is published by the American Chemical Society. 1155 Sixteenth Street N.W., Washington, DC 20036 Published by American Chemical Society. Copyright © American Chemical Society. However, no copyright claim is made to original U.S. Government works, or works produced by employees of any Commonwealth realm Crown government in the course of their duties.

Page 1 of 8 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

ACS Applied Materials & Interfaces

Zr-MOF/Polyaniline Composite Films with Exceptional Seebeck Coefficient for Thermoelectric Materials Applications Chih-Chien Lin,† Yi-Chia Huang,† Muhammad Usman,‡ Wen-Hsuan Chao,§ Wei-Keng Lin,|| Tzuoo-Tsair Luo,‡ Wha-Tzong Whang,† Chun-Hua Chen*† and Kuang-Lieh Lu*‡ † Department

of Materials Science and Engineering, National Chiao Tung University, Hsinchu 300, Taiwan of Chemistry, Academia Sinica, Taipei 115, Taiwan § Material and Chemical Research Laboratory, Industrial Technology Research Institute, Hsinchu 310, Taiwan || Department of Engineering and System Science, National Tsing Hua University, Hsinchu 300, Taiwan ‡ Institute

KEYWORDS Composites • Metal–organic frameworks • Polyaniline • Seebeck coefficient • Thermoelectric materials ABSTRACT: Controlling the polymerization of aniline in the presence of zirconium-based metal–organic frameworks (ZrMOFs) using polystyrene sulfonic acid as a dopant resulted in the formation of a new type of thermoelectric composite free standing film. Polyaniline chains interpenetrate into the Zr-MOFs to enhance the crystallinity of the polyaniline, resulting in an improved degree of electrical conductivity. In addition, the inherent porosity of the Zr-MOFs functions to suppress the increase in thermal conductivity, thus dramatically promoting a negative Seebeck coefficient. When 20 wt% Zr-MOF was used, a power factor of up to 664 μW/m·K2 was obtained, which was accompanied by a surprisingly large, negative Seebeck coefficient. The new class of MOF-based composites offers a new direction for developing new types of efficient thermoelectric materials.

Introduction Green energy sources are currently important issues in terms of reducing annual CO2 emissions. As such, strategies that decease the speed of global warming and that involve the reuse and transformation of waste heat into useful electrical power are subjects of great interest.1 Thermoelectric (TE) materials that can be used to convert heat flow into electricity are therefore highly desirable for further developing green power.2 Thermoelectric materials composed of organic polymers are subjects of increasing attention in recent years.3-5 Because of their light weight, low cost, high flexibility, ease of synthesis, ease of processing into versatile forms and relatively low thermal conductivity indicate that these types of TE materials have great potential for use in these areas.3-17 Some types of conductive polymers, such as polyaniline (PAn),6-10 PEDOT:PSS,11-14 polypyrole15-17 have been examined as TE materials. Among them, PAn is the most popular because of its excellent stability toward oxidation as well as its electrical, optical and thermoelectric properties.18 Recent studies indicate that the introduction of nanostructures in composite materials such as PAn/reduced graphene oxide,19 PAn/SWNT20-21 and PAn/Bi2Te322-23 can be employed to improve TE properties via tuning the crystallinity and morphologies of such materials. Nevertheless, those additives show diverse values for electrical conductivity and Seebeck coefficients. As a result, further investigations are therefore urgently needed.

Porous metal–organic frameworks (MOFs) have recently emerged as an important class of material due to their advantageous functional properties and topologically diverse architectures.24-33 Their high porosity, ease of surface tunability, and rich coordination chemistry provide an ideal platform for use in a wide array of potential applications in gas storage, catalysis, drug delivery and microelectronics devices.34-42 Zr-MOFs comprise a unique class of MOFs that are structurally diverse, and have excellent water stability.43-44 In particular, UiO-66, which is synthesized from the reaction of [Zr6O4(OH)4] clusters with 1,4-benzodicarboxylate, has an extremely large surface area and good potential electronics applications.4546 Here, we envisaged that a PAn thread-entangled UiO-66 composite blended with a dopant, such as polystyrene sulfonate (PSS), would result in the generation of a new type of TE material. The phase

Scheme 1. Schematic diagram showing the formation of Zr-MOF/PAn composites.

ACS Paragon Plus Environment

ACS Applied Materials & Interfaces 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 2 of 8

Scheme 2. Schematic diagram showing the composition of the thermoelectric free-standing thin films.

junction would allow phonon scattering, which would reduce thermal conductivity, while the dopant would enhance electrical conductivity. In addition, the Seebeck coefficient would expected to be significantly improved due to an ionic Soret effect (thermo-diffusion) caused by the interaction of each individual component.47 These three factors, in turn, would promote TE performance. To prove this concept, a threadlike interpenetrated network was prepared by inserting aniline into a porous ZrMOF followed by in-situ oxidative polymerization (Scheme 1). The final system contained two different structures that were held together to form a threadlike interpenetrating network structure, typically referred to as a semi- interpenetrating network (semi-IPN). A freestanding film of PSS-blended thread-interpenetrating ZrMOF/PAn/PSS composite was also prepared (Scheme 2). Significantly, this thread-interpenetrating composite film showed exceptional TE characteristics, with a huge negative Seebeck coefficient. More importantly, N-type TE materials are still rare and of fundamental importance, since a combination of P-type and N-type TE materials is essential for improving the performance of thermoelectric devices. Results and discussion To produce PAn with the Zr-MOFs, aniline (An) was absorbed to the MOFs by exchanging water for An. We used FT-IR to verify that An was successfully merged with the Zr-MOF. An IR absorption spectrum of a powdered sample Zr-MOF with water (ZB-W) or aniline (ZB-A) absorbed is displayed in Fig. S1. The characteristic peak of the IR absorption for An is 695 cm−1 (R–NH2 wagging), 1277 cm−1 (C–N stretching), and 1620 cm−1 (N–H scissoring).48 As can be seen, the three characteristic peaks for An were all present in the IR spectrum of ZB-A but were not seen in that for ZB-W. In addition, the characteristic peak for N–H

Figure 1. SEM image of (a) PAn and (b) ZB-W; 10-ZB-A/PAn synthesized using (c) fast, (d) medium, and (e) slow stirring speeds; (f) HRTEM image of the crystalline PAn of 10-ZBA/PAn synthesized using a fast stirring speed.

scissoring in the ZB-A was shifted slightly to a higher frequency due to the interaction of the PAn with the 1,4benzodicarboxylate of Zr-MOF (ZB). After merging the Zr-MOF with An, a ZB-A/PAn composite was prepared by the in-situ polymerization of An. Pristine PAn, ZB-W and ZB-A/PAn display different

morphologies, as shown in Figs. 1a to 1c: PAn as flakes, ZB-W as crystal particles, and ZB-A/PAn as crystals-linked with threads. As shown in Scheme 1, the key to creating a difference between pristine PAn and PAn in the composite was the “insitu polymerization of An with the Zr-MOF”, which led to the formation of a threadlike structure. During the in-situ polymerization, the PAn both on the surface and in the pores of the Zr-MOF would be pulled by interactive forces in the high-speed flow of a solution, thus causing the polymeric chain to become stretched. This would result in a change in the morphology of the PAn. To verify that such a flow does, in fact, affect the morphology of the complex, we changed the rotational speed of the stirring bar from rapid (900 rpm) to slow (300 rpm), which resulted in an clearly observed morphology change, as shown in Figs. 1c to 1e. When the rotational speed was decreased, the PAn morphology changed from a threadlike to a platelike structure. Decreasing the rotational speed caused more PAn to be absorbed to the surface of the Zr-MOF during the in-situ polymerization process. A higher stirring speed clearly leads to a PAn with a higher crystallinity as indicated by the appearance of lattice fringes of the PAn in the HRTEM image (Fig. 1f & S3b). The dspacing of the crystalline polyaniline is estimated to be about 0.36 nm, which is very close to a reported value (0.35 nm).49 The crystallinity is also confirmed by the PXRD

2

ACS Paragon Plus Environment

Page 3 of 8 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

ACS Applied Materials & Interfaces

Figure 2. The plot of thermoelectric properties (The absolute value of the Seebeck coefficient (|α|), thermal conductivity (κ), electrical conductivity (σ) and power factor value) dependent on the loading of Zr-MOF in ZBA/PAn/PSS1 film. characterization (vide infra, Fig. S5-6). In addition, nitrogen adsorption-desorption studies showed that the N2 uptake for the pristine Zr-MOF, 10-ZB-W/PAn and 10-ZB-A/PAn follow the trend: Zr-MOF >> 10-ZB-W/PAn > 10-ZB-A/PAn (Fig. S2). The pore sizes of the 10-ZB-A/PAn and 10-ZB-W/PAn are essentially negligible compared with that of the pristine ZrMOF. These results support the conclusion that the polyaniline chains are successfully interpenetrated into the Zr-MOFs.

The powder X-ray diffraction patterns of the ZB-A and ZB-W that are shown in Fig. S5 are similar. This suggests that An and water have no effect on the structure of the MOF. The amorphous pristine PAn displays a broad X-ray pattern, with no characteristic peaks. Whereas, both the ZB-A/PAn and ZB-W/PAn show the characteristic peaks 2θ = 17.4°, 25.0°, 25.3° and 27.9o. The 17.4°, 25.0° and 27.9° peaks arise from the ligand (BDC). The main diffraction peaks for both 5-ZB-A/PAn and 5-ZB-W/PAn are not clearly seen in the patterns, instead, only the ligand peaks are seen. This suggests that the Zr-MOF had slightly decomposed, presumably because of the low MOF loading. The 25.3° peak is assigned to the repeating unit of the PAn with a periodic polymer backbone. 49-50 It is important to note that the PXRD peak of the PAn backbone is sharper Table 1. Thermoelectric properties of the PAn/PSS films. Sample

α‖ μV/K

σ‖ S/m

κ┴ W/m·K

2.17 10−2

Power factor μW/m·K2 0.12

PAn/PSS1a

2325

10-ZB-W/PAn/PSS1a

-2645

4.9910−1

3.49

0.39

10-ZB-A/PAn/PSS1a

-6483

2.90

122

0.42

10-ZB-A/PAn/PSS2b

-6257

1.67

65.4

0.43

20-ZB-A/PAn/PSS2b

-17780

2.10

664

0.46

aThe bThe

molecular weight of PSS1 is 75,000 g/mol of the film. molecular weight of PSS2 is 1,000,000 g/mol of the film.

0.24

Scheme 3. Carrier thermo-diffusion in the composite. after the incorporation of the Zr-MOF, indicating that the crystallinity of the PAn was significantly enhanced when An was in-situ polymerized with the Zr-MOF, in particular, under conditions of a high stirring speed (see Fig. S6). A previous study reported in the literature also supports our observation that stretching PAn enhances its crystallinity.51 In addition, the powder XRD pattern of Zr-MOF/PAn/PSS films are similar to those for the Zr-MOF/PAn (Fig S7). The characteristic peak at 25.3° became sharper after synthesis with the Zr-MOF.52 Those results show that the Zr-MOF is an important component in the composite for the crystallinity of PAn. The Seebeck coefficient and electrical/thermal conductivity were investigated to determine the thermoelectric behavior of the Zr-MOF/PAn/PSS composite films. The findings indicated that our composite material exhibits a huge, unprecedented negative Seebeck coefficient of –17780 μV/K when 20 wt% Zr-MOF was used (Table 1). It was recently reported that a composite of an Zr-MOF with P-type polyaniline adopts N-type characteristics.53 In our case, a similar interaction between Zr-MOF and PAn/PSS was also observed where the two characteristic bands of PAn/PSS2 (400 nm for π to π* excitation and 800 nm for polaron absorption)54-55 are redshifted (from 400 nm to 415 nm and from 800 nm to 830 nm) in the UV-Vis absorption spectrum of 20-ZBA/PAn/PSS2 (Fig. S12). This indicates that the band gap is decreased due to the interactions of electron clouds of the zirconium (from the Zr-MOF) and nitrogen atoms (from the PAn).56-57 Furthermore, the carrier concentration and mobility of the composite films are increased with increasing Zr-MOF content (Table 2). Electron transfer becomes easier in the composite film. As a consequence, the Zr-MOF/PAn/PSS composite films exhibit N-type characteristics, resulting negative Seebeck coefficients, as shown in Table 1. Based on previous literature,58 Seebeck coefficients are enhanced with increasing carrier mobility. In addition, a strong ionic Soret effect (thermo-diffusion) from the polyelectrolyte of PAn/PSS also results

3

ACS Paragon Plus Environment

ACS Applied Materials & Interfaces 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Table 2. Hall carrier concentration and mobility of films.

PAn/PSS1

n cm-3 2.87 1013

μ cm2/Vs 4.39

P-type

5-ZB-A/PAn/PSS1

3.501014

4.89

N-type

10-ZB-A/PAn/PSS1

4.4210

5.03

N-type

Sample

15

Type

n: Carrier concentration; μ: Carrier mobility

in a huge Seebeck coefficient.59-60 During the development of a temperature gradient, the Zr-MOFs provide electrons to PAn/PSS by thermal excitation.61 By immobilizing ZrMOF as an electron donor to PAn/PSS, the Zr-MOF builds up a high positive charge at the hot side. PAn/PSS acts as an electron storage area at the cold end, resulting in the formation of a high concentration gradient of negative carriers which finally result in huge, negative Seebeck coefficients (Scheme 3). The electrical conductivity of the composite films increased significantly with increasing amount of Zr-MOF that was loaded into the PAn/PSS1 film (Table 1, Fig. 2 and S8). The conformation of the PAn in the composite films is extended with a slightly coiled arrangement with good crystallinity (Fig. 1c, 1f). These excellent electrical conductivities can mainly be attributed to the improved crystallinity of the PAn. A correlation between the crystallinity of PAn and electrical conductivity was also reported in a previous study.51 Furthermore, it is known that enhanced electrical conductivity also arises partially from the increasing carrier concentration and mobility.62-65 Our experimental results show that carrier concentration and mobility clearly increases with the degree of Zr-MOF loading and hence, the electrical conductivity of the composite films is significantly increased (see Table 1 & 2). A composite with an enhanced electrical conductivity and a high Seebeck coefficient would be predicted to have a positive impact on its power factor as well as its thermoelectric behavior. When 10 wt% ZB-A were used, a power factor of 122 μW/m·K2 was found, which is significantly higher than that for a pure PAn/PSS1 film, which has a power factor of 0.12 μW/m·K2. PSS, with a molecular weight of 75,000 g/mol can support free standing films for composites with MOF concentrations of up to 10 wt%. At higher levels than this, the films become brittle. The morphology of the Zr-MOF/PAn/PSS films show thread-interpenetrating characteristics and the surface roughness increases with increasing Zr-MOF content (Fig S4). To obtain better results, we used a longer chain PSS (PSS2; molecular weight 106 g/mol) which improved the integrity of the membrane. Using PSS2, the highest power factor was 664 μW/m·K2 for a film that contained 20 wt% ZB-A (20-ZB-A/PAn/PSS2 film), as shown in Table 1. To further illustrate the efficiency of this type of semiIPN composite for use as a thermoelectric material, we investigated its thermal conductivity, but only in perpendicular orientation (due to technical limitations

Page 4 of 8

associated with the measurements). The results were in the range of 0.24 to 0.42 W/m·K depending on the amount of Zr-MOF that had been loaded in the ZB-A/PAn/PSS film (Fig. 2). The increase in thermal conductivity is related to the increased electrical conductivity of the composites. Nevertheless, the slope of a plot for the thermal conductivity decreased significantly with increasing particle content in the film. As a consequence, the in-situ polymerization strategy using Zr-MOFs described herein offers a rare opportunity for substantially increasing the extent of interfacial and phonon scattering on the interface, which would, in turn, suppress the rate of increase in thermal conductivity. Our strategy that involves integrating polymers with ZrMOF results in the formation of new types of composite thermoelectric semi-IPN films with exceptionally high Seebeck coefficients, enhanced electrical conductivity and power factor. In addition, this design also suppresses the rate of increase in thermal conductivity. More importantly, novel composite films that are produced using combinations of PAn/PSS and a Zr-MOF, are low cost, light in weight, easy to synthesize, have better thermoelectric properties and are composed of free standing substrates. Such structures represent an ideal choice for applications of various MOF/polymer composites for use in thermoelectric applications. CONCLUSIONS The strategy outlined in this study, which involve through in-situ polymerization in the presence of Zr-MOFs results in the formation of new types of thermoelectric films (Zr-MOF/PAn/PSS) which exhibit excellent thermoelectric behavior. These thermoelectric composite films exhibit extraordinarily high negative Seebeck coefficients which can be optimized by using 20 wt% ZrMOF in the preparation. In addition, the electrical conductivity and power factors of the materials are also enhanced significantly compared to PAn/PSS films and the increment in thermal conductivity is suppressed. This work offers a new opportunity for taking advantage of the features of highly crystalline porous structures particularly metal–organic frameworks along with conductive polymers in developing novel thermoelectric materials. Experimental Section Preparation of Zr-MOFs: Zr-MOFs were synthesized by the method of pervious literature.45,66 A mixture of ZrCl4 (1.25 g), BDC (1.23 g), DMF (150 mL) and HCl (12 M; 10 mL) were refluxed and stirred at 100 °C for 24 h. Zr-MOF powders were collected by filtering and drying. To remove unreacted ligand, the Zr-MOFs refluxed in EtOH at 80 °C overnight, resulting in the isolation of the active Zr-MOFs. For further use, Zr-MOF powders were vacuum-dried in vials at 80 °C for 2 h. The Zr-MOFs were embedded with different liquids, water and aniline, respectively, for further study. After injecting the liquid into the vial, followed by filtering and washing with ethanol to remove the residual solvent, the sample was dried in an oven at 80 °C for 30 min. Those liquid-embedded Zr-MOFs were obtained. The 4

ACS Paragon Plus Environment

Page 5 of 8 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

ACS Applied Materials & Interfaces samples named as ZB-W and ZB-A by the rules in which W indicates water and A indicates aniline in the Zr-MOF. Preparation of Zr-MOFs/PAn Composites: ZrMOFs/PAn were prepared by first charging vacuum-dried Zr-MOFs into an appropriate proportion of An (ZB-A), then adding as HCl (1 M; 9 mL) solution followed by stirring on an ice bath. The resulting solution was then slowly dropped into an ammonium persulfate (APS) solution, which was from APS in HCl (1 M; 9 mL). The molar ratio of APS/An was 1.6/1. The reaction mixture was left to stir for 12 h after the final drop, then filtered, washed and dried overnight at 50 °C.67 The powder was denoted as ZB-A/PAn. ZB-W/PAn was prepared by a procedure similar to the above except that the order of addition of An to HCl was reversed. Preparation of PSS2 solution from PSSNa (M.W. = 1,000,000 g/mol): PSSNa (18 g) dissolved in DI water (82 mL), and then stirred with ion exchange resin (72 g) for 24 h. After ion exchanging from Na+ to H+ and removing the ion exchange resin by filtering, an 18 wt% PSSH solution was obtained. Preparation of Zr-MOFs/PAn/PSS Films: ZrMOFs/PAn/PSS solutions were prepared by charging vacuum-dried Zr-MOFs (74 mg) into An (0.097 mL), and then stirring the solution with DI water (5.5 mL) to give a homogeneous dispersion. An 18 wt% PSS (1.1 mL) solution was then added to the system with the weight ratio of PSS/An equal to 2/1, followed by slowly adding an APS solution dropwise for polymerization in ice bath. After reacting the sample for 12 h, the color of the solution of ZrMOFs/PAn/PSS changed from yellow to green. Finally, the composite films with thickness of about 20–40 μm were produced by dropping the solution on glass slides and dry at room temperature.

ASSOCIATED CONTENT Supporting Information. This supporting information is available free of charge via the Internet at http://pubs.acs.org. Included in this content are additional experimental information, analysis to supplement the results in this report.

Corresponding Author *(K.-L. Lu) E-mail: [email protected] *(C.-H. Chen) E-mail: [email protected]

ACKNOWLEDGMENT We appreciate Academia Sinica and Ministry of Science and Technology (MOST), Taiwan for financial supports under grants MOST 103-2221-E009-216, MOST 106-2113-M-001-032 and MOST 104-2221-E-009−180.

REFERENCES (1) Bell, L. E. Cooling, Heating, Generating Power, and Recovering Waste Heat with Thermoelectric Systems. Science 2008, 321, 1457-1461. (2) Bubnova, O.; Khan, Z. U.; Malti, A.; Braun, S.; Fahlman, M.; Berggren, M.; Crispin, X. Optimization of the Thermoelectric Figure of Merit in the Conducting Polymer Poly(3,4Ethylenedioxythiophene). Nat. Mater. 2011, 10, 429-433.

(3) Huang, D.; Wang, C.; Zou, Y.; Shen, X.; Zang, Y.; Shen, H.; Gao, X.; Yi, Y.; Xu, W.; Di, C. A.; Zhu, D. Bismuth Interfacial Doping of Organic Small Molecules for High Performance Ntype Thermoelectric Materials. Angew. Chem. Int. Ed. 2016, 55, 10672-10675. (4) Nonoguchi, Y.; Ohashi, K.; Kanazawa, R.; Ashiba, K.; Hata, K.; Nakagawa, T.; Adachi, C.; Tanase, T.; Kawai, T. Systematic Conversion of Single Walled Carbon Nanotubes into N-type Thermoelectric Materials by Molecular Dopants. Sci. Rep. 2013, 3, 3344. (5) Zhang, Q.; Sun, Y.; Xu, W.; Zhu, D. Organic Thermoelectric Materials: Emerging Green Energy Materials Converting Heat to Electricity Directly and Efficiently. Adv. Mater. 2014, 26, 6829-6851. (6) Zhao, Y.; Tang, G. S.; Yu, Z. Z.; Qi, J. S. The Effect of Graphite Oxide on the Thermoelectric Properties of Polyaniline. Carbon 2012, 50, 3064-3073. (7) Wang, L. M.; Yao, Q.; Bi, H.; Huang, F. Q.; Wang, Q.; Chen, L. D. Large Thermoelectric Power Factor in Polyaniline/Graphene Nanocomposite Films Prepared by Solution-Assistant Dispersing Method. J. Mater. Chem. A 2014, 2, 11107-11113. (8) Wang, L. M.; Yao, Q.; Bi, H.; Huang, F. Q.; Wang, Q.; Chen, L. D. PANI/Graphene Nanocomposite Films with High Thermoelectric Properties by Enhanced Molecular Ordering. J. Mater. Chem. A 2015, 3, 7086-7092. (9) Meng, C.; Liu, C.; Fan, S. A. Promising Approach to Enhanced Thermoelectric Properties Using Carbon Nanotube Networks. Adv. Mater. 2010, 22, 535-539. (10) Wang, W. J.; Zhang, Q. H.; Li, J. L.; Liu, X.; Wang, L. J.; Zhu, J. J.; Luo, W.; Jiang, W. An Efficient Thermoelectric Material: Preparation of Reduced Graphene Oxide/Polyaniline Hybrid Composites by Cryogenic Grinding. RSC Adv. 2015, 5, 8988-8995. (11) Luo, J. J.; Billep, D.; Waechtler, T.; Otto, T.; Toader, M.; Gordan, O.; Sheremet, E.; Martin, J.; Hietschold, M.; Zahnd, D. R. T.; Gessner, T. Enhancement of the Thermoelectric Properties of PEDOT:PSS Thin Films by Post-Treatment. J. Mater. Chem. A 2013, 1, 7576-7583. (12) Park, H.; Lee, S. H.; Kim, F. S.; Choi, H. H.; Cheong, I. W.; Kim, J. H. Enhanced Thermoelectric Properties of PEDOT: PSS Nanofilms by a Chemical Dedoping Process. J. Mater. Chem. A 2014, 2, 6532-6539. (13) Yoo, D.; Kim, J.; Lee, S. H.; Cho, W.; Choi, H. H.; Kim, F. S.; Kim, J. H. Effects of One- and Two-Dimensional Carbon Hybridization of PEDOT:PSS on the Power Factor of Polymer Thermoelectric Energy Conversion Devices. J. Mater. Chem. A 2015, 3, 6526-6533. (14) Tsai, T. C.; Chang, H. C.; Chen, C. H.; Huang, Y. C.; Whang, W. T. A. Facile Dedoping Approach for Effectively Tuning Thermoelectricity and Acidity of PEDOT:PSS Films. Org. Electron 2014, 15, 641-645. (15) Wu, J. S.; Sun, Y. M.; Pei, W. B.; Huang, L.; Xu, W.; Zhang, Q. C. Polypyrrole Nanotube Film for Flexible Thermoelectric Application. Synth. Met. 2014, 196, 173-177. (16) Wang, J.; Cai, K. F.; Shen, S.; Yin, J. L. Preparation and Thermoelectric Properties of Multi-Walled Carbon Nanotubes/Polypyrrole Composites. Synth. Met. 2014, 195, 132136. (17) Wang, L. Y.; Liu, F. Z.; Jin, C.; Zhang, T. R.; Yin, Q. J. Preparation of Polypyrrole/Graphene Nanosheets Composites with Enhanced Thermoelectric Properties. RSC Adv. 2014, 4, 46187-46193.

ACS Paragon Plus Environment

5

ACS Applied Materials & Interfaces 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

(18) Holland, E. R.; Pomfret, S. J.; Adams, P. N.; Monkman, A. P. Conductivity Studies of Polyaniline Doped with CSA. J. Phys-Condens Mat. 1996, 8, 2991-3002. (19) Islam, R.; Chan-Yu-King, R.; Brun, J. F.; Gors, C.; Addad, A.; Depriester, M.; Hadj-Sahraoui, A.; Roussel, F. Transport and Thermoelectric Properties of Polyaniline/Reduced Graphene Oxide Nanocomposites. Nanotechnology 2014, 25, 475705. (20) Yao, Q.; Wang, Q.; Wang, L. M.; Chen, L. D. Abnormally Enhanced Thermoelectric Transport Properties of SWNT/PANI Hybrid Films by the Strengthened PANI Molecular Ordering. Energ. Environ. Sci. 2014, 7, 3801-3807. (21) Chatterjee, M. J.; Banerjee, D.; Chatterjee, K. Composite of Single Walled Carbon Nanotube and Sulfosalicylic Acid Doped Polyaniline: A Thermoelectric Material. Mater. Res. Express. 2016, 3, 085009. (22) Toshima, N.; Imai, M.; Ichikawa, S. Organic–Inorganic Nanohybrids as Novel Thermoelectric Materials: Hybrids of Polyaniline and Bismuth(III) Telluride Nanoparticles. J. Electron. Mater. 2010, 40, 898-902. (23) Chatterjee, K.; Mitra, M.; Kargupta, K.; Ganguly, S.; Banerjee, D. Synthesis, Characterization and Enhanced Thermoelectric Performance of Structurally Ordered CableLike Novel Polyaniline-Bismuth Telluride Nanocomposite. Nanotechnology 2013, 24, 215703. (24) Li, H.; Eddaoudi, M.; O'Keeffe, M.; Yaghi, O. M. Design And Synthesis of an Exceptionally Stable and Highly Porous Metal–Organic Framework. Nature 1999, 402, 276-279. (25) Furukawa, S.; Reboul, J.; Diring, S.; Sumida, K.; Kitagawa, S. Structuring of Metal–Organic Frameworks at the Mesoscopic/Macroscopic Scale. Chem. Soc. Rev. 2014, 43, 5700-5734. (26) Meng, L.; Cheng, Q.; Kim, C.; Gao, W. Y.; Wojtas, L.; Chen, Y. S.; Zaworotko, M. J.; Zhang, X. P.; Ma, S. Crystal Engineering of a Microporous, Catalytically Active Fcu Topology MOF Using a Custom-Designed Metalloporphyrin Linker. Angew. Chem. Int. Ed. 2012, 51, 10082-10085. (27) Leong, W. L.; Vittal, J. J. One-Dimensional Coordination Polymers: Complexity and Diversity in Structures, Properties, and Applications. Chem. Rev. 2011, 111, 688-764. (28) Beziau, A.; Baudron, S. A.; Pogozhev, D.; Fluck, A.; Hosseini, M. W. Stepwise Construction of Grid-type Cu(II)Cd(II) Heterometallic MOFs Based on an ImidazoleAppended Dipyrrin Ligand. Chem. Commun. 2012, 48, 1031310315. (29) Huang, X.-C.; Lin, Y.-Y.; Zhang, J.-P.; Chen, X.-M.

Ligand-Directed Strategy for Zeolite-Type Metal–Organic Frameworks: Zinc(II) Imidazolates with Unusual Zeolitic Topologies. Angew. Chem. Int. Ed. 2006, 118, 1587-1589.

(30) Yang, J.; Ma, J.-F.; Batten, S. R. Polyrotaxane Metal– Organic Frameworks (PMOFs). Chem. Commun. 2012, 48, 7899-7912. (31) Luo, T. T.; Wu, H. C.; Jao, Y. C.; Huang, S. M.; Tseng, T.

W.; Wen, Y. S.; Lee, G. H.; Peng, S. M.; Lu, K. L. SelfAssembled Arrays of Single-Walled Metal–Organic Nanotubes. Angew. Chem. Int. Ed. 2009, 48, 9461-9464.

(32) Tseng, T. W.; Luo, T. T.; Liao, S. H.; Lu, K. H.; Lu, K. L. Isorecticular Synthesis of Dissectible Molecular Bamboo Tubes of Hexarhenium(I) Benzene-1,2,3,4,5,6-Hexaolate Complexes. Angew. Chem. Int. Ed. 2016, 55, 8343-8347. (33) Sun, L.; Campbell, M. G.; Dinca, M. Electrically Conductive Porous Metal–Organic Frameworks. Angew. Chem. Int. Ed. 2016, 55, 3566-3379

Page 6 of 8

(34) Zhu, Q. L.; Xia, W.; Akita, T.; Zou, R.; Xu, Q. Metal– Organic Framework-Derived Honeycomb-like Open Porous Nanostructures as Precious-Metal-Free Catalysts for Highly Efficient Oxygen Electroreduction. Adv. Mater. 2016, 28, 63916398. (35) Horike, S.; Dinca, M.; Tamaki, K.; Long, J. R. SizeSelective Lewis Acid Catalysis in a Microporous Metal–

Organic Framework With Exposed Mn2+ Coordination Sites. J. Am. Chem. Soc. 2008, 130, 5854-5855.

(36) Lee, J.; Farha, O. K; Roberts, J.; Scheidt, K. A.; Nguyen, S. T.; Hupp, J. T. Metal–Organic Framework Materials as Catalysts. Chem. Soc. Rev. 2009, 38, 1450-1459. (37) Zhao, X.; Xiao, B.; Fletcher, A. J.; Thomas, K. M.;

Bradshaw, D.; Rosseinsky, M. J. Hysteretic Adsorption and Desorption of Hydrogen by Nanoporous Metal–Organic Frameworks. Science 2004, 306, 1012-1015.

(38) Yang, S.; Lin, X.; Blake, A. J.; Walker, G. S.; Hubberstey, P.; Champness, N. R.; Schröder, M. Cation-Induced Kinetic Trapping and Enhanced Hydrogen Adsorption in a Modulated Anionic Metal–Organic Framework. Nat. Chem. 2009, 1, 487493. (39) Seo, Y.-K.; Yoon, J. W.; Lee, J. S.; Hwang, Y. K.; Jun, C.-H.; Chang, J.-S.; Wuttke, S.; Bazin, P.; Vimont, A.; Daturi, M.; Bourrelly, S.; Llewellyn, P. L.; Horcajada, P.; Serre, C.; Férey, G. Energy-Efficient Dehumidification over Hierachically Porous Metal–Organic Frameworks as Advanced Water Adsorbents. Adv. Mater. 2012, 24, 806-810. (40) Gao, Q.; Xu, J.; Cao, D.; Chang, Z.; Bu, X.-H. A Rigid Nested Metal–Organic Framework Featuring a Thermoresponsive Gating Effect Dominated by Counterions. Angew. Chem. Int. Ed. 2016, 55, 15027-15030. (41) Haider, G.; Usman, M.; Chen, T. P.; Perumal, P.; Lu, K. L.; Chen, Y. F. Electrically Driven White Light Emission from Intrinsic Metal–Organic Framework. ACS Nano 2016, 10, 8366. (42) Erickson, K. J.; Leonard, F.; Stavila, V.; Foster, M. E.; Spataru, C. D.; Jones, R. E.; Foley, B. M.; Hopkins, P. E.; Allendorf, M. D.; Talin, A. A. Thin Film Thermoelectric Metal– Organic Framework with High Seebeck Coefficient and Low Thermal Conductivity. Adv. Mater. 2015, 27, 3453-3459. (43) Bai, Y.; Dou, Y.; Xie, L. H.; Rutledge, W.; Li, J. R.; Zhou, H. C. Zr-Based Metal–Organic Frameworks: Design, Synthesis, Structure, and Applications. Chem. Soc. Rev. 2016, 45, 23272367. (44) Goswami, S.; Ray, D.; Otake, K. I.; Kung, C. W.; Garibay, S. J.; Islamoglu, T.; Atilgan, A.; Cui, Y.; Cramer, C. J.; Farha, O. K.; Hupp, J. T. A Porous, Electrically Conductive HexaZirconium(Iv) Metal–Organic Framework. Chem. Sci. 2018, 4477-4482. (45) Katz, M. J.; Brown, Z. J.; Colon, Y. J.; Siu, P. W.; Scheidt, K. A.; Snurr, R. Q.; Hupp, J. T.; Farha, O. K. A Facile Synthesis Of UiO-66, UiO-67 and Their Derivatives. Chem. Commun. 2013, 49, 9449-9451. (46) Yang, F.; Li, W.; Tang, B. Facile Synthesis of Amorphous Uio-66 (Zr-MOF) for Supercapacitor Application. J Alloys Compd. 2018, 733, 8-14. (47) Wang, H.; Ail, U.; Gabrielsson, R.; Berggren, M.; Crispin, X. Ionic Seebeck Effect in Conducting Polymers. Adv. Energ. Mater. 2015, 5, 1500044. (48) Wojciechowski, P. M.; Michalska, D. Theoretical Raman and Infrared Spectra, and Vibrational Assignment for ParaHalogenoanilines: DFT Study. Spectrochim Acta A 2007, 68, 948. 6

ACS Paragon Plus Environment

Page 7 of 8 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

ACS Applied Materials & Interfaces (49) Tao, Y.; Li, J.; Xie, A.; Li, S.; Chen, P.; Ni, L.; Shen, Y. Supramolecular Self-Assembly of Three-Dimensional Polyaniline and Polypyrrole Crystals. Chem. Commun. 2014, 50, 12757-12760. (50) Gemeay, A. H.; Mansour, I. A.; El-Sharkawy, R. G.; Zaki, A. B. Preparation and Characterization of Polyaniline/Manganese Dioxide Composites via Oxidative Polymerization: Effect of Acids. Eur. Polym. J. 2005, 41, 25752583. (51) Mitra, M.; Kulsi, C.; Chatterjee, K.; Kargupta, K.; Ganguly, S.; Banerjee, D.; Goswami, S. Reduced Graphene OxidePolyaniline Composites—Synthesis, Characterization and Optimization for Thermoelectric Applications. RSC Adv. 2015, 5, 31039-31048. (52) Cho, S.; Lee, J. S.; Jun, J.; Kim, S. G.; Jang, J. Fabrication of Water-Dispersible and Highly Conductive PSS-Doped PANI/Graphene Nanocomposites Using a High-Molecular Weight PSS Dopant and Their Application in H2S Detection. Nanoscale 2014, 6, 15181-15195. (53) Shao, L.; Wang, Q.; Ma, Z.; Ji, Z.; Wang, X.; Song, D.; Liu, Y.; Wang, N. A. High-Capacitance Flexible Solid-State Supercapacitor Based on Polyaniline and Metal–Organic Framework (Uio-66) Composites. J. Power Sources 2018, 379, 350-361. (54) Li, L.; Ferng, L.; Wei, Y.; Yang, C.; Ji, H. F. Effects of Acidity on the Size of Polyaniline-Poly(Sodium 4-Styrenesulfonate) Composite Particles and the Stability of Corresponding Colloids in Water. J. Colloid Interface Sci. 2012, 381, 11-16. (55) MacDiarmid, A. G.; Epstein, A. J. The Concept of Secondary Doping as Applied to Polyaniline. Synth. Met. 1994, 65, 103-116. (56) De Vos, A.; Hendrickx, K.; Van Der Voort, P.; Van Speybroeck, V.; Lejaeghere, K. Missing Linkers: An Alternative Pathway to UiO-66 Electronic Structure Engineering. Chem. Mater. 2017, 29, 3006-3019. (57) Hendrickx, K.; Vanpoucke, D. E. P.; Leus, K.; Lejaeghere, K.; Van Yperen-De Deyne, A.; Van Speybroeck, V.; Van Der Voort, P.; Hemelsoet, K. Understanding Intrinsic Light Absorption Properties of UiO-66 Frameworks: A Combined Theoretical and Experimental Study. Inorg. Chem. 2015, 54, 10701-10710. (58) Petsagkourakis, I.; Pavlopoulou, E.; Cloutet, E.; Chen, Y. F.; Liu, X.; Fahlman, M.; Berggren, M.; Crispin, X.; Dilhaire, S.; Fleury, G.; Hadziioannou, G. Correlating the Seebeck Coefficient of Thermoelectric Polymer Thin Films to Their Charge Transport Mechanism. Org. Electron. 2018, 52, 335-341. (59) Zhao, D.; Fabiano, S.; Berggren, M.; Crispin, X. Ionic Thermoelectric Gating Organic Transistors. Nat. Commun. 2017, 8, 14214. (60) Kim, S. L.; Lin, H. T.; Yu, C. Thermally Chargeable SolidState Supercapacitor. Adv. Energy Mater. 2016, 6, 1600546. (61) Li, G.; Josowicz, M.; Janata, J.; Semancik, S. Effect of Thermal Excitation on Intermolecular Charge Transfer Efficiency in Conducting Polyaniline. Appl. Phy. Lett. 2004, 85, 1187-1189. (62) Petsagkourakis, I.; Pavlopoulou, E.; Cloutet, E.; Chen, Y. F.; Liu, X.; Fahlman, M.; Berggren, M.; Crispin, X.; Dilhaire, S.; Fleury, G.; Hadziioannou, G. Correlating the Seebeck coefficient of thermoelectric polymer thin films to their charge transport mechanism. Org. Electron. 2018, 52, 335-341. (63) Mitra, M.; Kargupta, K.; Ganguly, S.; Goswami, S.; Banerjee, D. Facile Synthesis and Thermoelectric Properties of

Aluminum Doped Zinc Oxide/Polyaniline (AZO/PANI) Hybrid. Synth. Met. 2017, 228, 25-31. (64) Mitra, M.; Kulsi, C.; Kargupta, K.; Ganguly, S.; Banerjee, D. Composite of polyaniline-bismuth selenide with enhanced thermoelectric performance. J. Appl. Polym. Sci. 2018, 46887. (65) Ozawa, Y.; Ogihara, N.; Hasegawa, M.; Hiruta, O.; Ohba, N.; Kishida, Y. Intercalated Metal–Organic Frameworks with High Electronic Conductivity as Negative Electrode Materials for Hybrid Capacitors. Commun. Chem. 2018, 1, 65. (66) Zhang, W.; Lu, G.; Cui, C.; Liu, Y.; Li, S.; Yan, W.; Xing, C.; Chi, Y. R.; Yang, Y.; Huo, F. A. Family of Metal–Organic Frameworks Exhibiting Size-Selective Catalysis with Encapsulated Noble-Metal Nanoparticles. Adv. Mater. 2014, 26, 4056-4060. (67) Adams, P. N. L.; Laughlinl P. J.; Monkman, A. P. Low Temperature Synthesis of High Molecular Weight Polyaniline. Polymer 1995, 37, 3411-3417.

7

ACS Paragon Plus Environment

ACS Applied Materials & Interfaces 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 8 of 8

Table of Contents Bringing polyaniline and Zr-metal–organic frameworks (Zr-MOFs) together with polystyrene sulfonic acid as a dopant results in the formation of a free standing, thermoelectric composite film with a huge negative Seebeck coefficient and a high power factor.

8

ACS Paragon Plus Environment