Nanoparticle-Stacked Porous NickelâIron Nitride Nanosheet: A Highly

Subscriber access provided by - Access paid by the | UCSB Libraries

Letter

Nanoparticles-Stacked Porous Nickel-Iron Nitride Nanosheet: A Highly Efficient Bifunctional Electrocatalyst for Overall Water Splitting Yanyong Wang, Chao Xie, Dongdong Liu, Xiaobing Huang, Jia Huo, and Shuangyin Wang ACS Appl. Mater. Interfaces, Just Accepted Manuscript • DOI: 10.1021/acsami.6b05811 • Publication Date (Web): 27 Jun 2016 Downloaded from http://pubs.acs.org on June 28, 2016

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 free 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 accessible to all readers and 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.

ACS Applied Materials & Interfaces 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 16

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

Nanoparticles-Stacked Porous Nickel-Iron Nitride Nanosheet: A Highly Efficient Bifunctional Electrocatalyst for Overall Water Splitting Yanyong Wang,† Chao Xie,† Dongdong Liu,† Xiaobing Huang,‡ Jia Huo,†and Shuangyin Wang*† †State

Key laboratory of Chem/Bio-sensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, 410082, China, and

‡College

of Chemistry and Chemical Engineering, Hunan University of Arts and Science, Changde, China.

ABSTRACT: Nanoparticles-stacked porous Ni3FeN nanosheets were synthesized through a simple nitridation reaction of the corresponding LDHs. The nanosheet is composed of stacked nanoparticles with more active sites exposed for electrocatalytic reactions. Thus, it exhibited excellent oxygen evolution reaction performance having an extremely low overpotential of 223 mV at 10 mA/cm2 and hydrogen evolution reaction property with a very low overpotential of 45 mV at 10 mA/cm2. This electrocatalyst as bifunctional electrodes is used to overall water splitting in alkaline media, showing a high performance with 10 mA/cm2 at a cell voltage of 1.495V. KEYWORDS: nanoparticles-stacked porous Ni3FeN, bifunctional electrocatalysts, oxygen evolution reaction, hydrogen evolution reaction, water splitting

Although electrochemical water splitting offers a low cost, high purity, and environmentfriendly way for hydrogen production, its application suffers from limiting because overall water splitting is a strongly uphill reaction with larger overpotential, which is much higher than the theoretical minimum value of 1.23 V.1 To overcome the large overpotential for water splitting, it is critical to develop highly active bifunctional electrocatalysts for both oxygen evolution reaction (OER) and hydrogen evolution reaction (HER). Currently, noble metal oxides (IrO2 and RuO2)2-4 and platinum group metals5 have been extensively investigated as advanced OER and HER electrocatalysts, respectively, while these electrocatalysts suffer from limited reserves and high cost. Therefore, the further exploring of novel low-cost and earth-abundant electrocatalysts for water splitting is of essential importance. Recently, transition metals and their derivatives have been extensively applied for water splitting.6-14 In particular, layered double hydroxides (LDHs) have been extensively studied as a highly efficient electrocatalyst. LDHs are a class of two-dimensional layered materials, which are composed of cationic layers and charge-balancing anions in the interlayer region.15 This large interlayer distance will lead to remarkable increase of electrochemically accessible surface areas and improving electrocatalytic performance. For example, Luo et al.16 reported a bifunctional

ACS Paragon Plus Environment

1


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

electrocatalyst composed of NiFe LDH on nickel foam in alkaline media for overall water splitting, showing a good performance with 10 mA/cm2 at a cell voltage of 1.7 V. However, the large-scale application of LDHs electrocatalyst is seriously prohibited because of its poor electron conductivity and limited active sites.17 Transition metal nitrides (TMNs) are well suited for electrocatalyst application as they have high electrical conductivity and corrosion-resistance.18 The formation of nitrides favorably modifies the electronic structure such that the contraction of d-bands in metal nitrides results in a greater electron density near Fermi level.18 This is more conducive for electron transfer during the catalytic oxidation and reduction of water. Ni3N19 and Co4N20 have been reported as OER catalysts and CoMoNx,21 NiMo,22 Fe2Ni2N,23 Ni3FeN24 and MoN25 also have been studied as HER catalysts because of their low cost, high stability, and high electrical conductivity. Herein, we successfully prepared a nanoparticles-stacked porous Ni3FeN (NSP-Ni3FeN) electrocatalyst for overall water splitting. The NSP-Ni3FeN electrocatalysts are synthesized by a simple nitridation reaction with the corresponding LDHs. Firstly, Ni3Fe LDHs precursors grown on nickel foam (denoted as Ni3Fe LDHs/NF) are synthesized by a typical hydrothermal reaction. Secondly, this precursor is treated at high temperature under NH3 to obtain NSP-Ni3FeN on Ni foam (denoted as NSP-Ni3FeN/NF). The synthesis can retain basically lamellar morphology of LDHs, and also inherit great conductivity of TMNs. More interestingly, the lamellar Ni3FeN nanosheets are composed of stacked nanoparticles with more active sites exposed for electrocatalytic reactions, which differ from the Ni3FeN nanoparticles that cannot maintaine to the morphology of nanosheets. With the unique structural advantages, the NSP-Ni3FeN/NF exhibits excellent performance for both OER and HER and thus can be directly used for water electrolysis as an outstanding bifunctional electrocatalyst.


2

Page 2 of 16

Page 3 of 16

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


Figure 1. A) The SEM images of the Ni3Fe LDHs. B) The XRD pattern of the Ni3FeN. C) The SEM and D) the TEM images of the Ni3FeN. E), F), G), H), I) and J) The HRTEM images of the Ni3FeN.

Scanning electron microscopy (SEM) images of Ni3Fe LDHs (Figure 1A, Figure S1A and Figure S1B) indicate that Ni3Fe LDHs precursors are composed of a number of 2D nanosheets. Structural information on Ni3Fe LDHs precursors were investigated by X-ray diffraction (XRD). As shown in Figure S1C, the diffraction characteristic peaks could be well indexed to Ni3Fe LDHs (JCPDS Card No.40-025). The results clearly demonstrate that Ni3Fe LDHs precursor has


3


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

been successfully synthesized. By annealing the Ni3Fe LDHs precursor at 400

Page 4 of 16

under NH3

atmosphere, the Ni3FeN was synthesized. The XRD pattern of Ni3FeN (Figure 1B) shows that all the diffraction characteristic peaks could be well indexed to Ni3FeN (JCPDS Card No.50-1434) without detectable impurities. As evidenced by the morphology characterizations in Figure 1C and Figure 1D, the Ni3FeN nanosheets are composed of in-plane-stacked nanoparticles of 20-30 nm. The high-resolution TEM images (Figure 1E, 1G and 1H) of Ni3FeN nanosheets shows a lattice fringe with the spacing of 0.217 nm, consistent with that observed from the XRD patterns of the (111) plane and further proves the synthesis of the Ni3FeN. Meanwhile, the boundaries (Figure 1E), defects (Figure 1E and Figure 1F) and dislocations (Figure 1I and Figure 1J) are observed in the HRTEM images of the NSP-Ni3FeN nanosheets, which are considered to be active sites for electrocatalytisis.26 It is clearly observed that two adjacent nanoparticles merge together at the boundary without any visible gaps present (Figure 1E), suggesting that they are strongly interconnected with each other that ensures good electrical and mechanical contact for efficient and stable catalysis.27 The corresponding energy dispersive X-ray (EDX) images (Figure S6) also confirm the existence of Fe, Ni, and N. The X-ray photoelectron spectroscopy (XPS) was used to study the chemical state. The Ni 2p XPS spectrum (Figure 2A) shows that the peaks at 852.7 eV (Ni 2p3/2) and 869.9 eV (Ni2p1/2) are in accordance with Ni3N peaks.19 Meanwhile, the peaks at 855.5 eV (Ni 2p3/2), 861.1 eV (Ni 2p3/2), 873.2 eV (Ni 2p1/2) and 879.8 eV (Ni 2p1/2) which can be ascribed to Ni satellite peaks in NiO, demonstrating the occurance of surface partial oxidation.19 However, the NiO or other hydrated nickel oxides could not be detected by XRD, proving that the major phase is Ni3N. The Fe 2p XPS spectrum (Figure 2B) shows that the Fe 2p spectrum are split into two regions (Fe 2p1/2 and Fe 2p3/2) and four peaks: the peaks at 723.9 eV fitted in the Fe 2p1/2 region and the Peaks at 719.5 eV, 711.5 eV, 706.9 eV fitted in the Fe 2p3/2 region, the peak at 706.9 eV (Fe 2p3/2) is accordance with Fe metal peaks which could be considered as metallic iron nitride.28 The peaks at 711.5 eV (Fe 2p3/2) and 723.9 eV (Fe 2p1/2) can be ascribed to the peaks of Fe2O3 and the peak at 719.5 eV (Fe 2p3/2) was considered as the satellite peak of Fe3+. Similarly, the Fe2O3 or hydrated iron oxides also could not be detected by XRD, demonstrating that the major phase


4

Page 5 of 16

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


is iron nitride. The N 1s XPS spectrum (Figure 2C) consists of three peaks: the peak at 399.4 eV is in accordance with Fe-N compounds peaks,29 the peak at 397.4 eV is ascribe to metal nitride peak,18 the peak at 401.4 eV is consistent with graphitic N peak.30

Figure 2. XPS spectra of the Ni3FeN. A) Ni 2p, B) Fe 2p, and C) N 1s.

We also treated the Ni3Fe LDHs/NF under Ar at 400 the nickel Foam under NH3 at 400

(denoted as Ni3Fe LDHs-Ar) and

(denoted as Nickel Foam-NH3). The XRD (Figure S3A)

pattern of the Ni3Fe LDHs-Ar shows that the Ni3Fe LDHs phase transforms into Ni2FeO4 phase and NiO phase. The SEM images (Figure S3B) show that the morphology of the Ni3Fe LDHs-Ar changes to porous Ni2FeO4 and NiO nanosheets. On the other hand, as a control experiment, the Ni3Fe LDHs precursors were treated under NH3 at different temperatures (350 XRD pattern of the Ni3Fe LDHs-NH3-350

to 450

). The

shows that the Ni3Fe LDHs phase partly transforms

into Ni2FeO4 (Figure S4A), demonstrating that the Ni3Fe LDHs were unable to fully react with NH3 at 350

. The XRD pattern of the Ni3Fe LDHs-NH3-450

shows that the Ni3Fe LDHs

phase transforms into the compound of Ni3Fe alloy and Ni3FeN at 450

under NH3 (Figure

Figure S5A). Meanwhile, the SEM results show that the morphology of Ni3Fe LDHs-NH3-350 (Figure S4B) retain the nanosheets morphology of Ni3Fe LDHs. For Ni3Fe LDHs-NH3-450


5


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

(Figure S5B), the nanosheet morphology was completely destroyed. Thus, the optimized temperature for the reaction is 400

for the full conversion with reserved 2D morphology.

The OER activity of the NSP-Ni3FeN was measured by linear sweep voltammetric (LSV) between 1.1 and 1.6 V vs. reversible hydrogen electrode (RHE). The OER performances of Ni3Fe LDHs, Ni3Fe LDHs-Ar, and Nickel Foam-NH3 were also investigated for comparison. Figure 3A shows that Ni3FeN has an extremely small overpotential of 223 mV at 10 mA/cm2 in 1 M KOH solution which is significantly lower than the 250 mV of Ni3Fe LDHs-Ar and 330 mV of Nickel Foam-NH3. This overpotential at 10 mA/cm2 on Ni3FeN is lower than most of the OER electrocatalysts reported previously (Table S1). When current density arrived to 50 mA/cm2, the overpotential of the Ni3FeN, Ni3Fe LDHs, Ni3Fe LDHs-Ar, and Nickel Foam-NH3 is 248 mV, 293 mV, 279 mV, and 421 mV, respectively. In addition, this overpotentioal at 10 mA/cm2 on NSP-Ni3FeN is also lower than Pt/C and close to RhO2 for water oxide (Figure S12A). The excellent OER performance of Ni3FeN originated from the intrinsic properties and unique morphology. The metal nitrides own higher electrical conductivity (Figure S7) and the nanopartilces-stacked porous structure makes the catalyst have a relatively high BET surface of 19.69 m2/g (Figure S8). The increasing of electrical conductivity expedites the charge transfer from the electrocatalyst to the support electrode.20 The presence a number of grain boundaries, defects and dislocations in nanoparticles-stacked sheets can generate more active sites.26 Besides, the nanoparticles are strongly interconnected with each other at the boundary, which ensures good electrical and mechanical contact.27 These features make NSP-Ni3FeN suitable as OER electrocatalysts. The Tafel slope was determined to evaluate OER kinetic. As shown in the Figure 3B, the Tafel plots demonstrate that the Ni3FeN exhibits the smallest Tafel slope of 40 mV/decade among these catalysts, which is smaller than 51 mV/decade of Ni3Fe LDHs-Ar and 93 mV/decade of Nickel Foam-NH3. This also shows that the NSP-Ni3FeN has a lower Tafel slope than the Ni3Fe LDHs-Ar while they have the same porous nanosheets structure. The low Tafel slope also indicates efficient electron and mass transfer. Moreover, to investigate reaction kinetic of the NSP-Ni3FeN, electrochemical impedance spectroscopy (EIS) also was tested in a threeelectrode system in 1 M KOH. Figure 3C shows that the charge-transfer resistance of the NSP-


6

Page 6 of 16

Page 7 of 16

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


Ni3FeN exhibit a significantly decrease in comparison with the Ni3Fe LDHs-Ar and Nickel Foam-NH3 at the overpotential of 270 mV. The EIS results show that the NSP-Ni3FeN exhibits the fastest charge-transfer process among all five catalysts which is in good agreement with the excellent OER performance and small Tafel slope. Another rather important indicator for an OER electrocatalyst is its operational stability in alkaline solution. For this purpose, the life-span of the NSP-Ni3FeN (Figure 3D) was measured. After 1000 cycles and 2000 cycles, the LSV curves of the Ni3FeN for OER show almost no negative shift. The results show that NSP-Ni3FeN has a superior long-term stability for OER in alkaline media.

Figure 3. OER electrocatalytic performance. A) LSV curves for OER, B) Tafel plots and C) Nyquist plots obtained at 270 mV overpotential on Nickel Foam-NH3, Ni3Fe LDHs, Ni3Fe LDHs-Ar and Ni3FeN. D) Stability test of Ni3FeN for OER.

Compared to the samples treated at different temperatures under NH3, the Ni3FeN obtained at 400

has best OER activity due to the proper structure and the compound phase of the


7


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

Ni3FeN (Figure S9). The effect of the Ni/Fe ratio (1:1, 3:1, 5:1, 7:1 to 9:1) in the precursors was also studied. The Ni/Fe ratio of 3:1 shows the best OER performance (Figure S10A), indicating the optimal composition of the NSP-Ni3FeN.

Figure 4. HER electrocatalytic performance. A) LSV curves for HER, B) Tafel plots and C) Nyquist plots obtained by EIS at 150 mV overpotential for HER of the Nickel Foam-NH3, Ni3Fe LDHs, Ni3Fe LDHs-Ar and Ni3FeN. D) Stability test of Ni3FeN.

Likewise, the HER activity of the NSP-Ni3FeN was carried by linear sweep voltammetric (LSV) between -0.6 V and 0 V. Compared with the Ni3Fe LDH-Ar and the Nickel Foam-NH3, the NSP-Ni3FeN has an extremely small overpotential of 45 mV at 10 mA/cm2 which is significantly smaller than 241 mV of Ni3Fe LDHs, 179 mV of Ni3Fe LDHs-Ar and 238 mV of Nickel Foam-NH3 (Figure 4A). This overpotential at 10 mA/cm2 is the smallest among all of the NiFe-based HER electrocatalysts reported previously (Table S2 in the Supporting Information).


8

Page 8 of 16

Page 9 of 16

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


The HER performance on NSP-Ni3FeN is also close to Pt/C and superior to RhO2 (Figure S12B). For different annealing temperature under NH3, the NSP-Ni3FeN obtained at 400

also exhibits

the best HER performance (Figure S11A), which is attributed to the unique morphology of the nanoparticles-stacked porous nanosheets and the formation of Ni3FeN, leading to the increase of active sites and the electrical conductivity. The Ni/Fe ratio of 3:1 shows the best HER performance (Figure S10B). The Tafel plots (Figure 4B) demonstrate that the NSP-Ni3FeN exhibits excellent HER kinetic compared with Ni3Fe LDHs-Ar and Nickel Foam-NH3. The similar morphology of the Ni3FeN and the Ni3Fe LDHs-Ar with different Tafel slope demonstrate that the Ni3FeN indeed have more efficient electron transfer than the Ni3Fe LDHsAr for HER (Figure S7). Obviously, the NSP-Ni3FeN also has a lower Tafel slope (Figure S11B) than the Ni3Fe LDHs-NH3-350

and the Ni3Fe LDHs-NH3-450

. The EIS data reveals that the

NSP-Ni3FeN (Figure 4C) has a smallest charge-transfer resistance for HER compared with the Nickel Foam-NH3, the Ni3Fe LDHs and the Ni3Fe LDHs-Ar. The similar results also were observed in Figure S11C, the NSP-Ni3FeN has a smaller charge-transfer resistance for HER compared with the Ni3Fe LDHs-NH3-350

and Ni3Fe LDHs-NH3-450

. The small charge-

transfer resistance of the Ni3FeN can be well consistent with the high HER activity and the low Tafel slopes. The life-span test for the Ni3FeN for HER was also performed, and there is almost no obvious change before and after cycling (Figure 4D). More importantly, the as-prepared NSPNi3FeN shows comparable performance with the commercial Pt/C and RuO2 electrocatalysts for HER and OER, respectively (Figure S12). Given that the NSMP-Ni3FeN electrocatalyst exhibits excellent activity and stability for both OER and HER. A simple overall water splitting device is designed in a two-electrode system by Ni3FeN as both anode and cathode material. Figure 5 shows that the Ni3FeN as a bifunctional catalyst for overall water splitting need a very small cell voltage, only 1.495 V, to reach 10 mA/cm2 in 1 M KOH, which is superior to 1.933 V on Nickel Foam-NH3, 1.702 V on Ni3Fe LDHs, 1.67 V on NiFe LDHs-Ar-400

. This water splitting potential at 10 mA/cm2 is also

superior to previously investigated catalysts such as Ni2P/NF (1.63 V), Ni3S2/NF (1.76 V), NiSe/NF (1.63 V), NiFe/NC/NF(1.58 V), porous MoO2 nanosheets (1.53 V) and Ni/NiP (1.61 V) (Table S3).


9


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 16

Figure 5. LSV curves of overall water splitting for NSP-Ni3FeN in a two-electrode system with a scan rate of 2 mV/s.

In summary, we have synthesized a NSP-Ni3FeN as a highly efficient and stable bifunctional electrocatalyst for overall water splitting. This bifunctional electrocatalyst was derived from Ni3Fe LDHs which can be transformed successfully into Ni3FeN by ammonia annealing. The as-obtained nanosheet structure of Ni3FeN is composed of interconnected nanoparticles with the presence of boundaries, defects and dislocations. The nanoparticlesstacked porous nanosheets make bifunctional electrocatalyst have a higher specific area and more active sites for OER and HER. This bifunctional electrocatalyst is applied for overall water splitting and exhibit the lowest potential of 1.495 V to realize 10 mA/cm2. AUTHOR INFORMATION *S Supporting Information The Supporting Information is available free of charge on the ACS Publications website at http://pubs.acs.org. Experimental method, SEM, XRD, EDX, Electrical conductivity, Nitrogen adsorption-desorption isotherms and Electrocatalytic performance of the corresponding materials. Corresponding Author *Email:[email protected]. Present Address *Shuangyin Wang is currently at State Key laboratory of Chem/Bio-sensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, 410082, China


10

Page 11 of 16

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


ACKNOWLEGMENTS This work was supported by National Natural Science Foundation of China (Grant No.: 51402100, 21573066). REFERENCES 1. Zeng, K.; Zhang, D., Recent Progress in a Alkaline Water Electrolysis for Hydrogen Production and Applications. Prog. Energy Combust. Sci. 2010, 36 (3), 307-326. 2. Audichon, T.; Napporn, T. W.; Kokoh, K. B.; Canaff, C.; Morais, C.; Comminges, C., IrO2 Coated on RuO2 as Efficient and Stable Electroactive Nanocatalysts for Electrochemical Water Splitting. J. Phys. Chem. C. 2016. DOI:10.1021/acs.jpcc.5b11868 3. Browne, M. P.; Nolan, H.; Duesberg, G. S.; Colavita, P. E.; Lyons, M. E., Low Overpotential High Activity Mixed Manganese and Ruthenium Oxide Electrocatalysts for Oxygen Evolution Reaction in Alkaline Media. ACS Catal. 2016. DOI: 10.1021/acscatal.5b02069 4. Ortel, E.; Reier, T.; Strasser, P.; Kraehnert, R., Mesoporous IrO2 Films Templated by PEOPB-PEO Block-Copolymers: Self-assembly, Crystallization Behavior, and Electrocatalytic Performance. Chem. Mater. 2011, 23 (13), 3201-3209. 5. Jacobsson, T. J.; Fjällström, V.; Sahlberg, M.; Edoff, M.; Edvinsson, T., A Monolithic Device for Solar Water Splitting Based on Series Interconnected Thin Film Absorbers Reaching over 10% Solar-to-Hydrogen Efficiency. Energy Environ. Sci 2013, 6 (12), 3676-3683. 6. Masa, J.; Xia, W.; Sinev, I.; Zhao, A.; Sun, Z.; Grützke, S.; Weide, P.; Muhler, M.; Schuhmann, W., MnxOy/NC and CoxOy/NC Nanoparticles Embedded in a Nitrogen‐Doped Carbon Matrix for High‐Performance Bifunctional Oxygen Electrodes. Angew. Chem. Int. Ed. 2014, 53 (32), 8508-8512.


11


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 16

7. Popczun, E. J.; Read, C. G.; Roske, C. W.; Lewis, N. S.; Schaak, R. E., Highly Active Electrocatalysis of the Hydrogen Evolution Reaction by Cobalt Phosphide Nanoparticles. Angew. Chem. 2014, 126 (21), 5531-5534. 8. Long, X.; Li, G.; Wang, Z.; Zhu, H.; Zhang, T.; Xiao, S.; Guo, W.; Yang, S., Metallic Iron– Nickel Sulfide Ultrathin Nanosheets As a Highly Active Electrocatalyst for Hydrogen Evolution Reaction in Acidic Media. J. Am. Chem. Soc. 2015, 137 (37), 11900-11903. 9. Liu, T.; Liu, Q.; Asiri, A. M.; Luo, Y.; Sun, X., An Amorphous CoSe Film Behaves as an Active and Stable Full Water-Splitting Electrocatalyst under Strongly Alkaline Conditions. Chem. Commun. 2015, 51 (93), 16683-16686. 10. Jin, H.; Wang, J.; Su, D.; Wei, Z.; Pang, Z.; Wang, Y., In Situ Cobalt–Cobalt Oxide/N-doped Carbon Hybrids as Superior Bifunctional Electrocatalysts for Hydrogen and Oxygen Evolution. J. Am. Chem. Soc. 2015, 137 (7), 2688-2694. 11. Bezerra, C. W.; Zhang, L.; Lee, K.; Liu, H.; Marques, A. L.; Marques, E. P.; Wang, H.; Zhang, J., A Review of Fe–N/C and Co–N/C Catalysts for the Oxygen Reduction Reaction. Electrochim. Acta. 2008, 53 (15), 4937-4951. 12. Yan, Y.; Thia, L.; Xia, B. Y.; Ge, X.; Liu, Z.; Fisher, A.; Wang, X., Construction of Efficient 3D Gas Evolution Electrocatalyst for Hydrogen Evolution: Porous FeP Nanowire Arrays on Graphene Sheets. Adv. Sci. 2015, 2 (8). DOI: 10.1002/advs.201500120 13. Zhang, K.; Zhang, L.; Chen, X.; He, X.; Wang, X.; Dong, S.; Han, P.; Zhang, C.; Wang, S.; Gu, L., Mesoporous Cobalt Molybdenum Nitride: A Highly Active Bifunctional Electrocatalyst and Its Application in Lithium–O2 Batteries. J. Phys. Chem. C. 2013, 117 (2), 858-865. 14. Yan, Y.; Xia, B. Y.; Ge, X.; Liu, Z.; Fisher, A.; Wang, X., A Flexible Electrode Based on Iron Phosphide Nanotubes for Overall Water Splitting. Chem. Eur. 2015, 21 (50), 18062-18067.


12

Page 13 of 16

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


15. Wang, Q.; O’Hare, D., Recent Advances in the Synthesis and Application of Layered Double Hydroxide (LDH) Nanosheets. Chem. Rev. 2012, 112 (7), 4124-4155. 16. Luo, J.; Im, J.-H.; Mayer, M. T.; Schreier, M.; Nazeeruddin, M. K.; Park, N.-G.; Tilley, S. D.; Fan, H. J.; Grätzel, M., Water Photolysis at 12.3% Efficiency Via Perovskite Photovoltaics and Earth-Abundant Catalysts. Science 2014, 345 (6204), 1593-1596. 17. Gong, M.; Li, Y.; Wang, H.; Liang, Y.; Wu, J. Z.; Zhou, J.; Wang, J.; Regier, T.; Wei, F.; Dai, H., An Advanced Ni–Fe Layered Double Hydroxide Electrocatalyst for Water Oxidation. J. Am. Chem. Soc. 2013, 135 (23), 8452-8455. 18. Cao, B.; Veith, G. M.; Diaz, R. E.; Liu, J.; Stach, E. A.; Adzic, R. R.; Khalifah, P. G., Cobalt Molybdenum Oxynitrides: Synthesis, Structural Characterization, and Catalytic Activity for the Oxygen Reduction Reaction. Angew. Chem. Int. Ed. 2013, 52 (41), 10753-10757. 19. Xu, K.; Chen, P.; Li, X.; Tong, Y.; Ding, H.; Wu, X.; Chu, W.; Peng, Z.; Wu, C.; Xie, Y., Metallic Nickel Nitride Nanosheets Realizing Enhanced Electrochemical Water Oxidation. J. Am. Chem. Soc. 2015, 137 (12), 4119-4125. 20. Chen, P.; Xu, K.; Fang, Z.; Tong, Y.; Wu, J.; Lu, X.; Peng, X.; Ding, H.; Wu, C.; Xie, Y., Metallic Co4N Porous Nanowire Arrays Activated by Surface Oxidation as Electrocatalysts for the Oxygen Evolution Reaction. Angew. Chem. 2015, 127 (49), 14923-14927. 21. Cao, B.; Veith, G. M.; Neuefeind, J. C.; Adzic, R. R.; Khalifah, P. G., Mixed Close-Packed Cobalt Molybdenum Nitrides as Non-noble Metal Electrocatalysts for the Hydrogen Evolution Reaction. J. Am. Chem. Soc. 2013, 135 (51), 19186-19192. 22. Zhang, Y.; Ouyang, B.; Xu, J.; Chen, S.; Rawat, R. S.; Fan, H. J., 3D Porous Hierarchical Nickel–Molybdenum Nitrides Synthesized by RF Plasma as Highly Active and Stable Hydrogen


13


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 16

‐ Evolution ‐ Reaction Electrocatalysts. Adv. Energy. Mater. 2016. DOI: 10.1002/aenm. 201600221 23. Jiang, M.; Li, Y.; Lu, Z.; Sun, X.; Duan, X., Binary Nickel-iron Nitride Nanoarrays as Bifunctional Electrocatalysts for Overall Water Splitting. Inorg. Chem. Front. 2016. DOI: 10.1039/C5QI00232J 24. Jia, X.; Zhao, Y.; Chen, G.; Shang, L.; Shi, R.; Kang, X.; Waterhouse, G. I.; Wu, L. Z.; Tung, C. H.; Zhang, T., Ni3FeN Nanoparticles Derived from Ultrathin NiFe‐Layered Double Hydroxide Nanosheets: An Efficient Overall Water Splitting Electrocatalyst. Adv. Energy. Mater. 2016. DOI: 10.1002/aenm.201502585 25. Ojha, K.; Saha, S.; Kumar, B.; Hazra, K. S.; Ganguli, A. K., Controlling the Morphology and Efficiency of Nanostructured Molybdenum Nitride Electrocatalysts for the Hydrogen Evolution Reaction. ChemCatChem 2016, 8 (6), 1218-1225. 26. Tian, N.; Zhou, Z.-Y.; Sun, S.-G.; Ding, Y.; Wang, Z. L., Synthesis of Tetrahexahedral Platinum Nanocrystals with High-index Facets and High Electro-oxidation Activity. science 2007, 316 (5825), 732-735. 27. Wang, H.; Lee, H.-W.; Deng, Y.; Lu, Z.; Hsu, P.-C.; Liu, Y.; Lin, D.; Cui, Y., Bifunctional Non-noble Metal Oxide Nanoparticle Electrocatalysts through Lithium-induced Conversion for Overall Water Splitting. Nat. Commun. 2015, 6. DOI:10.1038/ ncomms8261 28. Ali-Löytty, H.; Louie, M. W.; Singh, M. R.; Li, L.; Sanchez Casalongue, H. G.; Ogasawara, H.; Crumlin, E. J.; Liu, Z.; Bell, A. T.; Nilsson, A., Ambient-Pressure XPS Study of a Ni-Fe Electrocatalyst for the Oxygen Evolution Reaction. J. Phys. Chem. C. 2016. DOI: 10.1021/acs.jpcc.5b10931


14

Page 15 of 16

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


29. Cui, Q.; Chao, S.; Wang, P.; Bai, Z.; Yan, H.; Wang, K.; Yang, L., Fe–N/C Catalysts Synthesized by Heat-treatment of Iron Triazine Carboxylic Acid Derivative Complex for Oxygen Reduction Reaction. RSC Adv. 2014, 4 (24), 12168-12174. 30. Kondo, T.; Guo, D.; Shikano, T.; Suzuki, T.; Sakurai, M.; Okada, S.; Nakamura, J., Observation of Landau levels on Nitrogen-doped Flat Graphite Surfaces without External Magnetic Fields. Sci. Rep. 2015, 5. DOI:10.1038/srep16412


15


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

TOC


16

Page 16 of 16

Nanoparticle-Stacked Porous NickelâIron Nitride Nanosheet: A Highly

Recommend Documents

Nanoparticle-Stacked Porous NickelâIron Nitride Nanosheet: A Highly