Ultrahigh Output Piezoelectric and Triboelectric Hybrid

Dec 3, 2018 - Wen He , Yongteng Qian , Byeok Song Lee , Fangfang Zhang , Aamir Rasheed , Jae-Eun Jung , and Dae Joon Kang. ACS Appl. Mater...
0 downloads 0 Views 848KB Size
Subscriber access provided by University of Rhode Island | University Libraries

Energy, Environmental, and Catalysis Applications

Ultrahigh Output Piezoelectric and Triboelectric Hybrid Nanogenerators Based on ZnO Nanoflakes/Polydimethylsiloxane Composite Films Wen He, Yongteng Qian, Byeok Song Lee, Fangfang Zhang, Aamir Rasheed, Jae-Eun Jung, and Dae Joon Kang ACS Appl. Mater. Interfaces, Just Accepted Manuscript • DOI: 10.1021/acsami.8b15410 • Publication Date (Web): 03 Dec 2018 Downloaded from http://pubs.acs.org on December 5, 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 20 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

Ultrahigh Output Piezoelectric and Triboelectric Hybrid Nanogenerators Based on ZnO Nanoflakes/Polydimethylsiloxane Composite Films Wen He1, Yongteng Qian1, Byeok Song Lee1, Fangfang Zhang1, Aamir Rasheed1, Jae-Eun Jung2, and Dae Joon Kang1, * 1Department

of Physics and Institute of Basic Science, Sungkyunkwan University, 2066, Seoburo, Jangan-gu, Suwon, Gyeonggi-do 16419, Republic of Korea

2Department

of Chemical Engineering, Hongik University, 94 Wausan-ro, Mapo-gu, Seoul 04066, Republic of Korea

ABSTRACT: We demonstrated a hybrid nanogenerator exploiting both piezoelectric and triboelectric effects induced from ZnO nanoflakes (NFs)/polydimethylsiloxane composite films through a facile, cost-effective fabrication method. This hybrid nanogenerator exhibited not only high piezoelectric output current owing to the enhanced surface piezoelectricity of the ZnO NFs but also high triboelectric output voltage owing to the pronounced triboelectrification of AuPDMS contact, producing peak-to-peak output voltage of ~470 V, current density of ~60 μA·cm−2, and average power density of ~28.2 mW·cm−2. Without additional energy storage devices, the hybrid nanogenerators with an area of 3×3 cm2 instantaneously lit up 180 commercial green light-emitting diodes through periodic hand compression. This approach may provide an innovative design for constructing high-performance and portable energy harvesting devices with enhanced power output, scavenging ambient mechanical energy from human motions in our daily life.

KEYWORDS:

Ultrahigh,

Hybrid

nanogenerator,

Piezoelectric,

Triboelectric,

Polydimethylsiloxane, ZnO nanoflakes

* To whom the correspondence should be addressed: [email protected]; +82-31-290-5906

ACS Paragon Plus Environment

1

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 20

1. INTRODUCTION Energy harvesting devices have been intensively explored not only to solve the global energy crisis issue, but also to power the implantable medical devices, wireless healthcare sensors, and portable electronics. 1-4 Mechanical energy is one of the most abundant and accessible energy resources in nature. Various approaches have been explored to convert ambient mechanical energy into electrical energy by exploiting a variety of phenomena such as pyroelectric effect, 5 electrostatic effect, 6 electromagnetic fields, 7 piezoelectric effect, 3, 8 and triboelectric effect. 9-11 Among these, energy harvesting device based on piezoelectrification is considered one of the promising strategies for generating electricity from ambient mechanical vibrations taking advantage of the electromechanical coupling effect in piezoelectric materials. For instance, ZnO nanoflakes (NFs) based piezoelectric nanogenerators (PENGs) have been explored for selfpowered electronics with high output power as reported in our earlier work.12, 13 Nevertheless, the relatively low output voltage greatly impeded the widespread of piezoelectric devices for powering portable electronic devices. Recently, energy harvesting device based on triboelectric nanogenerators (TENGs) has emerged as another promising approach to harvesting ambient mechanical energies, owing to the advantages of easy fabrication, high output voltage and wider choice of materials over other approaches.14 However, its low output current has still paused a great challenge to resolve in order to realize viable self-powered devices based on triboelectrification. Further, it should be noted that most energy harvesting devices discussed above are driven only by a single mechanism and thus further improvement can be expected by exploiting multiple mechanisms in an innovative way to greatly enhance the output performance suitable for powering the practical devices.15 Hence, extensive effort has been devoted very recently to exploiting both the

ACS Paragon Plus Environment

2

Page 3 of 20 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

triboelectric and the piezoelectric effects simultaneously for a novel mechanical-energy harvesting system.16,

17

Since the longitudinal PENG and single electrode TENG have similar

structure and output characteristics, the hybrid piezoelectric and triboelectric nanogenerators (PTNGs) can be successively obtained by replacing the dielectric in single electrode TENG with the piezoelectric material. We herein, report for the first time, a flexible ZnO NFs and Polydimethylsiloxane (PDMS) composite based PTNGs exploiting synergistic piezoelectric and triboelectric effects. Our innovative hybrid NGs can produce ultrahigh output power owing to a rational design that explores synergistic effects originated from piezoelectric and triboelectric mechanisms. ZnO NFs based PENGs and PDMS based TENGs were fabricated for comparison. Hand-compressing test was carried out to verify the practical applicability of the hybrid energy harvesting devices for converting vibrational mechanical energy sources from human activity into electrical energy. We found that the output power of hybrid NGs (in an area of 3×3 cm2) was able to directly light up 180 commercial green-emission LEDs without using any energy storage systems. 2. EXPERIMENTAL SECTION 2.1. Assembly of the PTNG, PENG, and TENG Devices. Before fabricating the PTNG devices, the bottom electrode was prepared as follows. First, ZnO NFs were grown on the Au coated polyethylene terephthalate (PET) substrate (purchased from Gawall Co., Korea) by a room temperature aqueous precipitation method following our previous report.12 The detailed synthetic procedure can be found in the supporting information. The PDMS was prepared by mixing two solutions (Sylgard 184, Dow Corning) containing both the elastomer and the curing agent with a mass ratio of 10:1 and spin-coated on the as-prepared ZnO NFs. The PDMS/ZnO

ACS Paragon Plus Environment

3

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 4 of 20

NFs composite film was then cured at 80 ºC for 2 h using a hot plate. Au coated PET substrate was used as the top and bottom current collector and triboelectric layer. For the construction of the bottom part of the PENG devices, the aforementioned bottom electrode was pasted on the poly(methyl methacrylate) (PMMA) plate using a double-side adhesive tape. On the top part, Au/PET substrate was glued to the inner surface of the top PMMA plate. The two plates were connected by two tweezers placed at the edges, leaving a space of 3 cm. Before taking the electrical measurements, the two electrodes were connected by copper wires using commercially available silver paste (Sigma Aldrich Co., Korea). ZnO NFs based PENGs and PDMS based TENGs were also fabricated for comparison. In particular, to fabricate PENGs, the PDMS mixture was spin-coated onto the ZnO-NF-grown on Au/PET substrate and cured at 80 ºC for 2 h in an oven. The PDMS/ZnO NFs/Au/PET substrate was used as the bottom electrode, while the top electrode was prepared by depositing a 50-nmthick Au layer onto the surface of the PDMS. Note that the fabrication recipe for triboelectric NGs is similar to that of hybrid PTNG except the growth step of ZnO NFs. 2.2. Material Characterizations and electrical measurements. The morphology of the ZnO NFs was examined using a field emission scanning electron microscopy (FESEM, JEOL JSM-7401F). The crystal nature of ZnO NFs was examined via the X-ray diffractometry (XRD, D8 FOCUS 2200 V, Bruker AXS) and a high-resolution transmission electron microscopy (HRTEM, FE-TEM JEM2100F). The electrical characteristics of the NG devices were measured using a digital oscilloscope (Lecroy Wave Runner 6100a) and a low-noise current amplifier (Keithley, SR570). 3. RESULTS AND DISCUSSION

ACS Paragon Plus Environment

4

Page 5 of 20 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

The schematic of the fabrication process of PTNG devices are shown in Figure 1a, which is described in more detail in the experimental section. Figure 1b (i) shows the schematic illustration of PTNG device configuration. Owing to their decent robustness, light-weight, and low cost, PMMA was selected as the protective layer for the PTNG device. PET was used as the substrate owing to its extreme flexibility desirable for flexible NG device applications. Due to the high electronegativity, flexibility, transparency, and cost effectiveness, PDMS has been extensively investigated in a variety of TENG works.18-20 Au is extremely-high positive tribomaterial and also acted as the electrode to connect the external load. The FESEM images in Figure 1b(ii) and inset exhibited that high density ZnO NFs were uniformly grown on the Au/PET substrate and the individual ZnO NFs form a plate that has the thickness less than 10 nm. In addition, a photograph of a real PTNG device was taken as shown in Figure 1c. Figure 1d reveals the typical XRD pattern of ZnO NFs. Corresponding to 2 theta angles, the intensity peaks of XRD pattern assigned to (110), (002), (101), (102), (110), (103), (200), (112), (201), (004), and (202) planes are in excellent agreement with hexagonal wurtzite ZnO (JCPDS 89-1397). HRTEM was also carried out to further confirm the crystalline nature of the ZnO NFs. The HRTEM and selected area electron diffraction (SAED) images of individual ZnO NFs are also shown in Figure 1e and the inset. The crystal lattice fringes are clear, and the average distance between the adjacent lattice planes is 0.52 nm, which corresponds to (0001) crystal planes of hexagonal wurtzite ZnO. Note that the ZnO grown preferably along c-axis orientation exhibited the best piezoelectric coefficient response for the ZnO NF based nanogenerators. The effect of working force on the PTNG’s (fabricated in an area of 1 × 1 cm2) electrical properties was systematically investigated. The peak-to-peak open-circuit (OC) output voltage and short-circuit (SC) current density were then tested when the ZnO NFs/PDMS film was under

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

Page 6 of 20

various compressive forces (1 N, 3 N, 5 N, 7 N, and 9 N) at a constant frequency of 10 Hz. The maximum peak-to-peak output voltage, current density, and average output power density were calculated to be ~ 470 V, 60 A cm−2, and 28.2 mW cm−2. This output performance is superior to the results reported elsewhere (Table S1). It is noteworthy that the peak-to-peak output voltage and current density of the devices increase gradually with the applied force varying from 1- 7 N (see in Figure 2a and Figure 2b). This could be due to the fact that the increased working force may provide full contact between two friction layers of PDMS and Au layer and that higher load transfers more piezoelectric polarization of ZnO NFs. However, the performance was deteriorated as the compressive force was larger than 7 N. The detailed account of this phenomenon is given in the following. Utilizing the piezoelectric effect, the open-circuit (OC) voltage at piezoelectric region (𝑉𝑝) caused by the polarization can be obtained according to the following equation:21 𝑉𝑝 = 𝑇33𝑔33

(1)

electric T 3where σ stress 33 is3isthe the along piezovoltage thickness the coeffi direction of the cient, piezoelectric of the respectively. applied material, force, g where T is the thickness of the piezoelectric material, σ33 is the stress along the direction of the applied force, and 𝑔33is the piezo-electric voltage coefficient, respectively. Single electrode triboelectric nanogenerator has a similar structure with the longitudinal PENG. The OC voltage at triboelectric region (𝑉𝑡) can be calculated as: Funct. Mater.2014, 24, 3332 Adv.

1𝑇

𝑉𝑡 = 2  𝑞

(2)

Where T is the thickness of the PDMS, and  is the permittivity of the dielectric material, 𝑞 is the surface charge density, respectively.

ACS Paragon Plus Environment

6

Page 7 of 20 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

For the two-terminal hybrid PTNG, with a small applied force, the increasing force can increase 33 in the piezoelectric material, and 𝑞 on the contact surface, thus promoting the output performance of hybrid PTNG. However, further increase in the applied force may damage the structure of ZnO Nanoflakes/Polydimethylsiloxane composite films, resulting in the reduction of the output voltage and current density. Hence, the electrical output starts to decline.3,13 Structures mode four-terminal Figure2. tion electrifi electric pressed cation material state, materials can i.e., two-terminal, materials material state, cation be released For separated CR-state), of divided each the PE–TENGs i.e., materials contacted being conductor-to-dielectric (contacted CP-state), mode, into and three-terminal, 3)pressed two piezoelectric three contacted the but are electrifi but electric 2)steps: piezoelectric (contacted illustrated two released and and electrifi 1) cation generamaterial two piezoin andFor comparison, we also characterized the output performance of PENG and TENG devices under a periodic mechanical force of 7 N and a working frequency of 10 Hz. As shown in the Figure 3a and Figure 3b,the peak-to-peak output voltages of TENG and PENG are 200 V and 130 V, while the peak-to-peak short-circuit current density are 22 and 37 μA cm−2, respectively. The output of hybrid PTNG is much higher than the PENG and the TENG, indicating highly synergistic contributions of triboelectric and piezoelectric effects. To demonstrate the potential utilization of our hybrid energy harvesting systems, we attempted to power a large number of commercially available green-emission LEDs. 70 LEDs (forward voltage of 2.7 V) constituting the “SKKU” letters were connected to the TENG in series through a full-wave bridge circuit. The hybrid PTNG device of 1×1 cm2 in size could generate high peakto-peak open-circuit voltage of 220 V (Figure 4a) and short-circuit current density of 15 μA cm−2 (Figure 4b) under the periodic hand compression, and can light up 70 LEDs (Figure 4c and Video S1). Furthermore, a larger device with area of 3×3 cm2 hybrid PTNG device could instantaneously and simultaneously turned on 180 LEDs (Figure 4d and Video S2). The electricity generated from the PTNG device (size of 1 × 1 cm2) can also be stored in energy storage device such as capacitor after repeatable hand compressing process. The equivalent electric circuit of the PTNG based self-charging system is shown in Figure 4e. A full-wave

ACS Paragon Plus Environment

7

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 20

bridge rectifier was connected between the PTNG device and the commercial capacitor (1 F) to achieve the energy storage process. As Figure 4f and Video S3 presents, the voltage of the commercial capacitor quickly increases (~2.6 V/min) when the PTNG is compressed and becomes flat once the compressive motion stops. The as-prepared PTNG device belongs to the two-terminal conductor-to-dielectric mode hybrid NG.21,22 We proposed a plausible electric energy conversion mechanism of the hybrid PTNG based on the coupling between triboelectric and piezoelectric effects, as depicted in Figure 5. The electric generation can be divided into three steps: 1) two triboelectric layers contacted and piezoelectric material being pressed, 2) two triboelectric layers contacted but piezoelectric material released, 3) two triboelectric layers separated and piezoelectric material released. Typically, when an external force is applied on the top electrode, thus bringing the gold and PDMS into contact, generating positive triboelectric charges on the gold side and negative charges on the surface of PDMS.23 At the same time, a piezoelectric potential is established in the ZnO NFs when the device is compressed by this external force.24 Consequently, an electrostatic force is exerted to drive mobile free electrons through an external load from the top to the bottom electrodes to balance this piezoelectric potential. These electrons are then accumulated at the interface between the NFs and the gold bottom electrodes. Conversely, holes are accumulated on the gold top electrode to balance negative piezoelectric potential of the top ZnO NFs. Therefore, the entire positive potential on the top gold electrodes is generated by synergistic effects of triboelectric charges and the piezoelectric potential of ZnO NFs. The top gold electrode and the ZnO NFs/PDMS is separated as the external force is removed; the piezoelectric potential in ZnO NFs is also removed at the same time. Owing to the electric potential difference, the electrons will flow back from the bottom to the top gold electrodes

ACS Paragon Plus Environment

8

Page 9 of 20 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

through the external load to screen with holes on the top electrode and then more holes are accumulated on the bottom gold electrode to balance negative potential of triboelectric charges on the surface of top side of PDMS.15, 25 Thus, the electrical potential of the bottom electrode becomes higher than that of top electrode. Once the compressive process is engaged again, the electrons will flow back in the reversed direction due to the piezoelectric potential induced by the deformation of ZnO NFs/PDMS, hence influencing the triboelectric charges of the top gold electrode and PDMS. Finally, both positive and negative currents and voltages can be observed by electrons that flow back and forth between the two electrodes during the periodic compressive processes. Note that, the output current and voltage during separation process has a smaller magnitude but longer duration than that for contact process (inset of Figure 4a and Figure 4b). This can be explained by faster contact resulting from external force impact compared to slower separation caused by restoring force of the tweezers.10, 23 4. CONCLUSIONS A triboelectric and piezoelectric hybrid NG is proposed, which is composed of ZnO NFs and PDMS films. The gigantic output performance of hybrid TPNG can be obtained by the synergistic effects of piezoelectricity and triboelectricity. The highest output power with ZnO based NGs can be achieved during the compression test under a compressive force of 7 N and driving frequency of 10 Hz. Typically, the output from the hybrid NG reached up to 470 V for the peak-to-peak output open-circuit voltage and 60 μA cm−2 for the short-circuit current density. This excellent performance is an indicative of the high potential of the hybrid TPNG device for portable self-driven systems and energy harvesting of human motion for application in our daily life.

ACS Paragon Plus Environment

9

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 10 of 20

ASSOCIATED CONTENT Supporting information: the synthesis procedure of ZnO NFs (PDF) and the comparison table summarizing the output performance of hybrid NGs reported elsewhere and our work; Video clips showing 70 LEDs (forward voltage of 2.7 V) forming the “SKKU” letters lit up by a periodic hand compression,180 commercial green light-emitting diodes lit up by the periodic hand compression through the PTNG as well as a commercial capacitor charged through the PTNG. AUTHOR INFORMATION Corresponding Author: E-mail: [email protected] ORCID Wen He: 0000-0002-7673-7274 Dae Joon Kang: 0000-0002-4030-4071 NOTE The authors declare they have no competing financial interest. ACKNOWLEDGMENTS This work was supported by the Fundamental Technology Research Program through the National Research Foundation of Korea, with grants funded by the Korean government (2014M3A7B4052201).

ACS Paragon Plus Environment

10

Page 11 of 20 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

REFERENCES (1) Wang, Z. L. Self-Powered Nanosensors and Nanosystems. Adv. Mater. 2012, 24, 280285. (2) Zheng, Q.; Zhang, H.; Shi, B.; Xue, X.; Liu, Z.; Jin, Y.; Ma, Y.; Zou, Y.; Wang, X.; An, Z.; Tang, W.; Zhang, W.; Yang, F.; Liu, Y.; Lang, X.; Xu, Z.; Li, Z.; Wang, Z. L. In Vivo SelfPowered Wireless Cardiac Monitoring via Implantable Triboelectric Nanogenerator. ACS Nano 2016, 10, 65106518. (3) He, W.; Van Ngoc, H.; Qian, Y. T.; Hwang, J. S.; Yan, Y. P.; Choi, H.; Kang, D. J. Synthesis of Ultra-thin Tellurium Nanoflakes on Textiles for High-performance Flexible and Wearable Nanogenerators. Appl. Surf. Sci. 2017, 392, 10551061. (4) Wen, Z.; Yeh, M.-H.; Guo, H.; Wang, J.; Zi, Y.; Xu, W.; Deng, J.; Zhu, L.; Wang, X.; Hu, C.; Zhu, L.; Sun, X.; Wang, Z. L. Self-powered Textile for Wearable Electronics by Hybridizing Fiber-shaped Nanogenerators, Solar Cells, and Supercapacitors. Sci. Adv. 2016, 2. (5) Yang, Y.; Guo, W.; Pradel, K. C.; Zhu, G.; Zhou, Y.; Zhang, Y.; Hu, Y.; Lin, L.; Wang, Z. L. Pyroelectric Nanogenerators for Harvesting Thermoelectric Energy. Nano Lett. 2012, 12, 28332838. (6) Tian, H.; Ma, S.; Zhao, H.-M.; Wu, C.; Ge, J.; Xie, D.; Yang, Y.; Ren, T.-L. Flexible Electrostatic Nanogenerator Using Graphene Oxide Film. Nanoscale 2013, 5, 89518957. (7) Roundy, S.; Takahashi, E. A Planar Electromagnetic Energy Harvesting Transducer Using a Multi-pole Magnetic Plate. Sens. Actuators, A 2013, 195, 98104. (8) Wu, W.; Wang, L.; Li, Y.; Zhang, F.; Lin, L.; Niu, S.; Chenet, D.; Zhang, X.; Hao, Y.; Heinz, T. F.; Hone, J.; Wang, Z. L. Piezoelectricity of Single-atomic-layer MoS2 for Energy Conversion and Piezotronics. Nature 2014, 514, 470474.

ACS Paragon Plus Environment

11

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 12 of 20

(9) Zi, Y.; Wang, J.; Wang, S.; Li, S.; Wen, Z.; Guo, H.; Wang, Z. L. Effective Energy Storage from a Triboelectric Nanogenerator. Nat. Commun. 2016, 7, 10987. (10) Chun, J.; Ye, B. U.; Lee, J. W.; Choi, D.; Kang, C.-Y.; Kim, S.-W.; Wang, Z. L.; Baik, J. M. Boosted Output Performance of Triboelectric Nanogenerator via Electric Double Layer Effect. Nat. Commun. 2016, 7, 12985. (11) Chen, S. W.; Cao, X.; Wang, N.; Ma, L.; Zhu, H. R.; Willander, M.; Jie, Y.; Wang, Z. L. An Ultrathin Flexible Single-Electrode Triboelectric-Nanogenerator for Mechanical Energy Harvesting and Instantaneous Force Sensing. Adv. Energy Mater. 2017, 7, 1601255. (12) Van Ngoc, H.; Kang, D. J. Flexible, Transparent and Exceptionally High Power Output Nanogenerators Based on Ultrathin ZnO Nanoflakes. Nanoscale 2016, 8, 50595066. (13) Qian, Y.T.; Kang, D. J. Polydimethylsiloxane/ZnO Nanoflakes/Three-Dimensional Graphene Heterostructures for High Performance Flexible Energy Harvesters with Simultaneous Piezoelectric and Triboelectric Generation. ACS Appl. Mater. Interfaces 2018, 10, 3228132288. (14) Dhakar, L.; Gudla, S.; Shan, X.; Wang, Z.; Tay, F. E. H.; Heng, C.-H.; Lee, C. Large Scale Triboelectric Nanogenerator and Self-Powered Pressure Sensor Array Using Low Cost Roll-to-Roll UV Embossing. Sci. Rep. 2016, 6, 22253. (15) Wang, X.; Yang, B.; Liu, J.; Zhu, Y.; Yang, C.; He, Q. A Flexible TriboelectricPiezoelectric

Hybrid

Nanogenerator

Based

on

P(VDF-TrFE)

Nanofibers

and

PDMS/MWCNT for Wearable Devices. Sci. Rep. 2016, 6, 36409. (16) Suo, G.; Yu, Y.; Zhang, Z.; Wang, S.; Zhao, P.; Li, J.; Wang, X. Piezoelectric and Triboelectric

Dual

Effects

in

Mechanical-Energy

Harvesting

Using

ACS Paragon Plus Environment

12

Page 13 of 20 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

BaTiO3/Polydimethylsiloxane Composite Film. ACS Appl. Mater. Interfaces 2016, 8, 3433534341. (17) Jung, W.-S.; Kang, M.-G.; Moon, H. G.; Baek, S.-H.; Yoon, S.-J.; Wang, Z.-L.; Kim, S.-W.; Kang, C.-Y. High Output Piezo/Triboelectric Hybrid Generator. Sci. Rep. 2015, 5, 9309. (18) Chen, J.; Guo, H.; He, X.; Liu, G.; Xi, Y.; Shi, H.; Hu, C. Enhancing Performance of Triboelectric Nanogenerator by Filling High Dielectric Nanoparticles into Sponge PDMS Film. ACS Appl. Mater. Interfaces 2016, 8, 736744. (19) Harnchana, V.; Ngoc, H. V.; He, W.; Rasheed, A.; Park, H.; Amornkitbamrung, V.; Kang, D. J. Enhanced Power Output of a Triboelectric Nanogenerator using Poly(dimethylsiloxane) Modified with Graphene Oxide and Sodium Dodecyl Sulfate, ACS Appl. Mater. Interfaces 2018, 10, 2526325272 (20) Jirayupat, C.; Wongwiriyapan, W.; Kasamechonchung, P.; Wutikhun, T.; Tantisantisom, K.; Rayanasukha, Y.; Jiemsakul, T.; Tansarawiput, C.; Liangruksa, M.; Khanchaitit, P.; Horprathum, M.; Porntheeraphat, S.; Klamchuen, A. Piezoelectric-Induced Triboelectric Hybrid Nanogenerators Based on the ZnO Nanowire Layer Decorated on the Au/polydimethylsiloxane–Al Structure for Enhanced Triboelectric Performance, ACS Appl. Mater. Interfaces 2018, 10, 64336440. (21) Han, M.; Chen, X.; Yu, B.; Zhang, H. Coupling of Piezoelectric and Triboelectric Effects: from Theoretical Analysis to Experimental Verification, Adv. Electron. Mater. 2015, 1, 1500187. (22) Yi, F.; Wang, X.; Niu, S.; Li, S.; Yin, Y.; Dai, K.; Zhang, G.; Lin, L.; Wen, Z.; Guo, H.; Wang, J.; Yeh, M.-H.; Zi, Y.; Liao, Q.; You, Z.; Zhang, Y.; Wang, Z. L. A Highly Shape-

ACS Paragon Plus Environment

13

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 14 of 20

adaptive, Stretchable Design Based on Conductive Liquid for Energy Harvesting and SelfPowered Biomechanical Monitoring. Sci Adv 2016, 2, e1501624. (23) Zhu, G.; Lin, Z.-H.; Jing, Q.; Bai, P.; Pan, C.; Yang, Y.; Zhou, Y.; Wang, Z. L. Toward Large-Scale Energy Harvesting by a Nanoparticle-Enhanced Triboelectric Nanogenerator. Nano Lett. 2013, 13, 847853. (24) Zhu, G.; Wang, A. C.; Liu, Y.; Zhou, Y.; Wang, Z. L. Functional Electrical Stimulation by Nanogenerator with 58 V Output Voltage. Nano Lett. 2012, 12, 30863090. (25) Shi, B.; Zheng, Q.; Jiang, W.; Yan, L.; Wang, X.; Liu, H.; Yao, Y.; Li, Z.; Wang, Z. L. A Packaged Self-Powered System with Universal Connectors Based on Hybridized Nanogenerators. Adv. Mater. 2016, 28, 846852.

ACS Paragon Plus Environment

14

Page 15 of 20 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 1. Schematic illustration and characterizations of the PTNG devices. (a) Fabrication process of the PTNG devices. (b) The schematic device structure (i) and SEM images of a PTNG device (ii). (c) The photograph of the as prepared PTNG. (d) XRD pattern and (e) HRTEM image of ZnO NFs (inset shows SAED patterns).

ACS Paragon Plus Environment

15

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 16 of 20

Figure 2. The peak-to-peak output voltage (a) and current density (b) of the PTNG hybrid NG device during repeated compressive motions under various compressive forces.

ACS Paragon Plus Environment

16

Page 17 of 20 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 3. The peak-to-peak open-circuit voltage and short-circuit current density of the TENG (a) and PENG (b).

ACS Paragon Plus Environment

17

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 18 of 20

Figure 4. (a) The open-circuit voltage and (b) short-circuit current under repeatable hand compressive process for a device area of 1 × 1 cm2. Instantaneous activation of (c) 70 LEDs and (d) 180 LEDs under periodic hand compression for device areas of 1 × 1 cm2 and 3 × 3 cm2, respectively. (e) Working electric circuit of the PTNG based self-charging system. (f) Charging a commercial capacitor with the PTNG device.

ACS Paragon Plus Environment

18

Page 19 of 20 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 5. Proposed mechanism for power generation from the hybrid PTNG through periodic compressing test. (The output signal from triboelectric effect was depicted in white, while the output signal in red is generated by piezoelectric effect.)

ACS Paragon Plus Environment

19

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 20 of 20

Abstract Graphic

ACS Paragon Plus Environment

20