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1.
Cobalt–Nickel Layered Double Hydroxides Modified on TiO2 Nanotube Arrays for Highly Efficient and Stable PEC Water Splitting
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Weijian Chen Taotao Wang Jiawei Xue Shikuo Li Zidan Wang Song Sun 《Small (Weinheim an der Bergstrasse, Germany)》2017,13(10)
TiO2‐based photoanodes have attracted extensive attention worldwide for photoelectrochemical (PEC) water splitting, but these materials still suffer from poor electron–hole separation and low photoconversion efficiency. Here, the high PEC water splitting activity and long‐term stability against photocorrosion of well‐aligned hierarchical TiO2@CoNi‐layered double hydroxides nanotube arrays (TiO2@CoNi‐LDHs NTAs) are reported. The typical TiO2@CoNi‐LDHs NTAs exhibits enhancing photocurrent density of 4.4 mA cm?2 at a potential of 1.23 V (vs reversible hydrogen electrode) under AM 1.5G simulated sunlight (100 mW cm?2), 3.3 times higher than that of the pristine TiO2 sample. Moreover, this hierarchical electrode displays excellent stability against photocorrosion with initial activity loss no more than 1.0% even after 10 h irradiation in Na2SO4 electrolyte solution (pH 6.8), much competitive to those reported TiO2‐based photoelectrodes. This work may offer a combinatorial synthesis strategy for the preparation of hierarchical architectures with high PEC performances. 相似文献
2.
Hao Sun Ling Chen Yuebin Lian Wenjuan Yang Ling Lin Yufeng Chen Jiabin Xu Dan Wang Xiaoqin Yang Mark H. Rümmerli Jun Guo Jun Zhong Zhao Deng Yan Jiao Yang Peng Shizhang Qiao 《Advanced materials (Deerfield Beach, Fla.)》2020,32(52):2006784
Layered double hydroxides (LDHs) have been recognized as potent electrocatalysts for oxygen evolution reaction (OER), but are lacking in hydrogen evolution reaction (HER) activities due to the sluggish kinetics of water dissociation in alkaline medium. Herein, aiming to simultaneously bolster the HER and OER kinetics, a metal–organic framework (MOF) mediated topotactic transformation tactic is deployed to fabricate holey ternary CoFeNi LDHs on nickel foam, exposing polygonal mesopores with atomistic edge steps and lattice defects. The optimized catalyst requires only an external voltage of 1.49 V to afford the water splitting current density of 10 mA cm−2 apart from the superb electrolytic stability, far surpassing the benchmark Pt/C||RuO2 couple. More importantly, mechanistic investigations utilizing advanced spectroscopies in conjunction with density function theory (DFT) understandings unravel while the synergetic effect among under-coordinated metal centers lowers the energy barrier of water dissociation, Fe-doping enables further modulating the d-band density of states (DOS) of Co and Ni in favor of intermediates binding, thereby promoting the intrinsic HER activity. Operando Raman studies reveal negligible structural change of the LDHs during the HER process, whereas for OER the active sites can quickly turn into oxyhydroxides in the presence of lattice defects and under-coordinated metal centers. 相似文献
3.
Ultrathin Porous NiFeV Ternary Layer Hydroxide Nanosheets as a Highly Efficient Bifunctional Electrocatalyst for Overall Water Splitting
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Khang Ngoc Dinh Penglun Zheng Zhengfei Dai Yu Zhang Raksha Dangol Yun Zheng Bing Li Yun Zong Qingyu Yan 《Small (Weinheim an der Bergstrasse, Germany)》2018,14(8)
Herein, the hydrothermal synthesis of porous ultrathin ternary NiFeV layer double hydroxides (LDHs) nanosheets grown on Nickel foam (NF) substrate as a highly efficient electrode toward overall water splitting in alkaline media is reported. The lateral size of the nanosheets is about a few hundreds of nanometers with the thickness of ≈10 nm. Among all molar ratios investigated, the Ni0.75Fe0.125V0.125‐LDHs/NF electrode depicts the optimized performance. It displays an excellent catalytic activity with a modest overpotential of 231 mV for the oxygen evolution reaction (OER) and 125 mV for the hydrogen evolution reaction (HER) in 1.0 m KOH electrolyte. Its exceptional activity is further shown in its small Tafel slope of 39.4 and 62.0 mV dec?1 for OER and HER, respectively. More importantly, remarkable durability and stability are also observed. When used for overall water splitting, the Ni0.75Fe0.125V0.125‐LDHs/NF electrodes require a voltage of only 1.591 V to reach 10 mA cm?2 in alkaline solution. These outstanding performances are mainly attributed to the synergistic effect of the ternary metal system that boosts the intrinsic catalytic activity and active surface area. This work explores a promising way to achieve the optimal inexpensive Ni‐based hydroxide electrocatalyst for overall water splitting. 相似文献
4.
Nils C. Hildebrandt Julia Soldat Roland Marschall 《Small (Weinheim an der Bergstrasse, Germany)》2015,11(17):2051-2057
The (111)‐layered perovskite materials Ba5Ta4O15, Ba5Ta2Nb2O15 and Ba5Nb4O15 are prepared with nanofiber morphology via electrospinning for the first time. The nanofibers are built up from small single crystals, with up to several micrometers length even after calcination. The formation mechanism is investigated in detail, revealing an intermediate formation of amorphous barium carbonate strengthening the nanofiber morphology for high temperature treatment. All nanofiber compounds are able to generate hydrogen without any co‐catalyst in photocatalytic reformation of methanol. After photodeposition of Rh‐Cr2O3 co‐catalysts, the nanofibers show better activity in overall water splitting compared to sol–gel‐derived powders. 相似文献
5.
Heterostructured TiO2 Nanorod@Nanobowl Arrays for Efficient Photoelectrochemical Water Splitting
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Wenhui Wang Jingya Dong Xiaozhou Ye Yang Li Yurong Ma Limin Qi 《Small (Weinheim an der Bergstrasse, Germany)》2016,12(11):1469-1478
Heterostructured TiO2 nanorod@nanobowl (NR@NB) arrays consisting of rutile TiO2 nanorods grown on the inner surface of arrayed anatase TiO2 nanobowls are designed and fabricated as a new type of photoanodes for photoelectrochemical (PEC) water splitting. The unique heterostructures with a hierarchical architecture are readily fabricated by interfacial nanosphere lithography followed by hydrothermal growth. Owing to the two‐dimensionally arrayed structure of anatase nanobowls and the nearly radial alignment of rutile nanorods, the TiO2 NR@NB arrays provide multiple scattering centers and hence exhibit an enhanced light harvesting ability. Meanwhile, the large surface area of the NR@NB arrays enhances the contact with the electrolyte while the nanorods offer direct pathways for fast electron transfer. Moreover, the rutile/anatase phase junction in the NR@NB heterostructure improves charge separation because of the facilitated electron transfer. Accordingly, the PEC measurements of the TiO2 NR@NB arrays on the fluoride‐doped tin oxide (FTO) substrate show significantly enhanced photocatalytic properties for water splitting. Under AM1.5G solar light irradiation, the unmodified TiO2 NR@NB array photoelectrode yields a photocurrent density of 1.24 mA cm–2 at 1.23 V with respect to the reversible hydrogen electrode, which is almost two times higher than that of the TiO2 nanorods grown directly on the FTO substrate. 相似文献
6.
Xinzhe Li Yiyun Fang Jun Wang Bin Wei Kun Qi Hui Ying Hoh Qiaoyan Hao Tao Sun Zhongchang Wang Zongyou Yin Yupeng Zhang Jiong Lu Qiaoliang Bao Chenliang Su 《Small (Weinheim an der Bergstrasse, Germany)》2019,15(30)
Achieving large‐sized and thinly layered 2D metal phosphorus trichalcogenides with high quality and yield has been an urgent quest due to extraordinary physical/chemical characteristics for multiple applications. Nevertheless, current preparation methodologies suffer from uncontrolled thicknesses, uneven morphologies and area distributions, long processing times, and inferior quality. Here, a sonication‐free and fast (in minutes) electrochemical cathodic exfoliation approach is reported that can prepare large‐sized (typically ≈150 µm2) and thinly layered (≈70% monolayer) NiPS3 flakes with high crystallinity and pure phase structure with a yield ≈80%. During the electrochemical exfoliation process, the tetra‐n‐butylammonium salt with a large ionic diameter is decomposed into gaseous species after the intercalation and efficiently expands the tightly stratified bulk NiPS3 crystals, as revealed by in situ and ex situ characterizations. Atomically thin NiPS3 flakes can be obtained by slight manual shaking rather than sonication, which largely preserves in‐plane structural integrity with large size and minimum damage. The obtained high quality NiPS3 offers a new and ideal model for overall water splitting due to its inherent fully exposed S and P atoms that are often the active sites for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). Consequently, the bifunctional NiPS3 exhibits outstanding performance for overall water splitting. 相似文献
7.
Vertical Growth of 2D Amorphous FePO4 Nanosheet on Ni Foam: Outer and Inner Structural Design for Superior Water Splitting
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Lei Yang Zenglong Guo Jing Huang Yaoning Xi Rongjie Gao Ge Su Wei Wang Lixin Cao Bohua Dong 《Advanced materials (Deerfield Beach, Fla.)》2017,29(46)
Rational design of highly efficient bifunctional electrocatalysts based on 3D transition‐metal‐based materials for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) is of great importance for sustainable energy conversion processes. Herein, a novel strategy involving outer and inner structural engineering is developed for superior water splitting via in situ vertical growth of 2D amorphous FePO4 nanosheets on Ni foam (Am FePO4/NF). Careful experiments and density functional theory calculations show that the inner and outer structural engineering contributing to the synergistic effects of 2D morphology, amorphous structure, conductive substrate, and Ni?Fe mixed phosphate lead to superior electrocatalytic activity toward OER and HER. Furthermore, a two‐electrode electrolyzer assembled using Am FePO4/NF as an electrocatalyst at both electrodes gives current densities of 10 and 100 mA cm?2 at potentials of 1.54 and 1.72 V, respectively, which is comparable to the best bifunctional electrocatalyst reported in the literature. The strategies, introduced in the present work, may open new opportunities for the rational design of other 3D transition‐metal‐based electrocatalyst through an outer and inner structural control to strengthen the electrocatalytic performance. 相似文献
8.
Porous Hybrid Network of Graphene and Metal Oxide Nanosheets as Useful Matrix for Improving the Electrode Performance of Layered Double Hydroxides
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Tae‐Ha Gu Jayavant L. Gunjakar In Young Kim Sharad B. Patil Jang Mee Lee Xiaoyan Jin Nam‐Suk Lee Seong‐Ju Hwang 《Small (Weinheim an der Bergstrasse, Germany)》2015,11(32):3921-3931
Mesoporous hybrid network of reduced graphene oxide (rG‐O) and layered MnO2 nanosheets could act as an efficient immobilization matrix for improving the electrochemical activity of layered double hydroxide (LDH). The control of MnO2/rG‐O ratio is crucial in optimizing the porous structure and electrical conductivity of the resulting hybrid structure. The immobilization of Co‐Al‐LDH on hybrid MnO2/rG‐O network is more effective in enhancing its electrode activity compared with that of on pure rG‐O network. The Co‐Al‐LDH?rG‐O?MnO2 nanohybrid deliveres a greater specific capacitance than does MnO2‐free Co‐Al‐LDH?rG‐O nanohybrid. The beneficial effect of MnO2 incorporation on the electrode performance of nanohybrid is more prominent for higher current density and faster scan rate, underscoring the significant enhancement of the electron transport of Co‐Al‐LDH?rG‐O. This is supported by electrochemical impedance spectroscopy. The present study clearly demonstrates the usefulness of the porously assembled hybrid network of graphene and metal oxide nanosheets as an effective platform for exploring efficient LDH‐based functional materials. 相似文献
9.
FeS2/CoS2 Interface Nanosheets as Efficient Bifunctional Electrocatalyst for Overall Water Splitting
Electrochemical water splitting to produce hydrogen and oxygen, as an important reaction for renewable energy storage, needs highly efficient and stable catalysts. Herein, FeS2/CoS2 interface nanosheets (NSs) as efficient bifunctional electrocatalysts for overall water splitting are reported. The thickness and interface disordered structure with rich defects of FeS2/CoS2 NSs are confirmed by atomic force microscopy and high‐resolution transmission electron microscopy. Furthermore, extended X‐ray absorption fine structure spectroscopy clarifies that FeS2/CoS2 NSs with sulfur vacancies, which can further increase electrocatalytic performance. Benefiting from the interface nanosheets' structure with abundant defects, the FeS2/CoS2 NSs show remarkable hydrogen evolution reaction (HER) performance with a low overpotential of 78.2 mV at 10 mA cm−2 and a superior stability for 80 h in 1.0 m KOH, and an overpotential of 302 mV at 100 mA cm−2 for the oxygen evolution reaction (OER). More importantly, the FeS2/CoS2 NSs display excellent performance for overall water splitting with a voltage of 1.47 V to achieve current density of 10 mA cm−2 and maintain the activity for at least 21 h. The present work highlights the importance of engineering interface nanosheets with rich defects based on transition metal dichalcogenides for boosting the HER and OER performance. 相似文献
10.
Pengzuo Chen Tianpei Zhou Mengxing Zhang Yun Tong Chengan Zhong Nan Zhang Lidong Zhang Changzheng Wu Yi Xie 《Advanced materials (Deerfield Beach, Fla.)》2017,29(30)
Developing non‐noble‐metal electrocatalysts with high activity and low cost for both the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) is of paramount importance for improving the generation of H2 fuel by electrocatalytic water‐splitting. This study puts forward a new N‐anion‐decorated Ni3S2 material synthesized by a simple one‐step calcination route, acting as a superior bifunctional electrocatalyst for the OER/HER for the first time. The introduction of N anions significantly modifies the morphology and electronic structure of Ni3S2, bringing high surface active sites exposure, enhanced electrical conductivity, optimal HER Gibbs free‐energy (ΔGH*), and water adsorption energy change (ΔGH2O*). Remarkably, the obtained N‐Ni3S2/NF 3D electrode exhibits extremely low overpotentials of 330 and 110 mV to reach a current density of 100 and 10 mA cm?2 for the OER and HER in 1.0 m KOH, respectively. Moreover, an overall water‐splitting device comprising this electrode delivers a current density of 10 mA cm?2 at a very low cell voltage of 1.48 V. Our finding introduces a new way to design advanced bifunctional catalysts for water splitting. 相似文献
11.
Xiaoyi Meng Junxing Han Liang Lu Genrui Qiu Zhong Lin Wang Chunwen Sun 《Small (Weinheim an der Bergstrasse, Germany)》2019,15(41)
Developing nonprecious electrocatalysts with superior activity and durability for electrochemical water splitting is of great interest but challenging due to the large overpotential required above the thermodynamic standard potential of water splitting (1.23 V). Here, in situ growth of Fe2+‐doped layered double (Ni, Fe) hydroxide (NiFe(II,III)‐LDH) on nickel foam with well‐defined hexagonal morphology and high crystallinity by a redox reaction between Fe3+ and nickel foam under hydrothermal conditions is reported. Benefiting from tuning the local atomic structure by self‐doping Fe2+, the NiFe(II,III)‐LDH catalyst with higher amounts of Fe2+ exhibits high activity toward oxygen evolution reaction (OER) as well as hydrogen evolution reaction (HER) activity. Moreover, the optimized NiFe(II,III)‐LDH catalyst for OER (O‐NiFe(II,III)‐LDH) and catalyst for HER (H‐NiFe(II,III)‐LDH) show overpotentials of 140 and 113 mV, respectively, at a current density of 10 mA cm?2 in 1 m KOH aqueous electrolyte. Using the catalysts for overall water splitting in two‐electrode configuration, a low overpotential of just 1.54 V is required at a benchmark current density of 10 mA cm?2. Furthermore, it is demonstrated that electrolysis of the water device can be drived by a self‐powered system through integrating a triboelectric nanogenerator and battery, showing a promising way to realize self‐powered electrochemical systems. 相似文献
12.
Pradheep Thiyagarajan Hyo‐Jin Ahn Jung‐Soo Lee Jong‐Chul Yoon Ji‐Hyun Jang 《Small (Weinheim an der Bergstrasse, Germany)》2013,9(13):2341-2347
A hierarchically patterned metal/semiconductor (gold nanoparticles/ZnO nanowires) nanostructure with maximized photon trapping effects is fabricated via interference lithography (IL) for plasmon enhanced photo‐electrochemical water splitting in the visible region of light. Compared with unpatterned (plain) gold nanoparticles‐coated ZnO NWs (Au NPs/ZnO NWs), the hierarchically patterned Au NPs/ZnO NWs hybrid structures demonstrate higher and wider absorption bands of light leading to increased surface enhanced Raman scattering due to the light trapping effects achieved by the combination of two different nanostructure dimensions; furthermore, pronounced plasmonic enhancement of water splitting is verified in the hierarchically patterned Au NPs/ZnO NWs structures in the visible region. The excellent performance of the hierarchically patterned Au NPs/ZnO NWs indicates that the combination of pre‐determined two different dimensions has great potential for application in solar energy conversion, light emitting diodes, as well as SERS substrates and photoelectrodes for water splitting. 相似文献
13.
Self‐Assembly of Single‐Layer CoAl‐Layered Double Hydroxide Nanosheets on 3D Graphene Network Used as Highly Efficient Electrocatalyst for Oxygen Evolution Reaction
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Jianfeng Ping Yixian Wang Qipeng Lu Bo Chen Junze Chen Ying Huang Qinglang Ma Chaoliang Tan Jian Yang Xiehong Cao Zhijuan Wang Jian Wu Yibin Ying Hua Zhang 《Advanced materials (Deerfield Beach, Fla.)》2016,28(35):7640-7645
14.
Yingjie Li Bolong Huang Yingjun Sun Mingchuan Luo Yong Yang Yingnan Qin Lei Wang Chunji Li Fan Lv Weiyu Zhang Shaojun Guo 《Small (Weinheim an der Bergstrasse, Germany)》2019,15(1)
The development of cost‐efficient, active, and stable electrode materials as bifunctional catalysts for electrochemical water splitting is crucial to high‐performance renewable energy storage and conversion devices. In this work, the synthesis of Co‐based multi‐metal borides nanochains with amorphous structure is reported for boosting the oxygen evolution (OER) and hydrogen evolution reactions (HER) by one‐pot NaBH4 reduction of Co2+, Ni2+, and Fe2+ under ambient temperature. In all the investigated Co‐based metal borides, NiCoFeB nanochains show the excellent OER performance with a low overpotential of 284 mV at 10 mA cm‐2 and Tafel slope of 46 mV dec‐1, respectively, together with excellent catalytic stability, and robust HER performance with an overpotential of 345 mV at 10 mA cm‐2. The density functional theory (DFT) calculations reveal that the excellent electrocatalytic performance is mainly attributed to optimal electronic structure by tuning the Co‐3d band activities by the incorporation of Ni and Fe for enhanced water splitting via the potentially existed Co0 state. Moreover, the electrolyzer using NiCoFeB nanochains as anode and cathode offers 10 mA cm‐2 at a cell voltage of 1.81 V, comparable to commercial Pt/C // Ir/C, providing a simple method to design and explore highly efficient and cheap bifunctional electrocatalysts for overall water splitting. 相似文献
15.
16.
F. Pelayo García de Arquer Oleksandr S. Bushuyev Phil De Luna Cao‐Thang Dinh Ali Seifitokaldani Makhsud I. Saidaminov Chih‐Shan Tan Li Na Quan Andrew Proppe Md. Golam Kibria Shana O. Kelley David Sinton Edward H. Sargent 《Advanced materials (Deerfield Beach, Fla.)》2018,30(38)
Electrochemical reduction of CO2 is a compelling route to store renewable electricity in the form of carbon‐based fuels. Efficient electrochemical reduction of CO2 requires catalysts that combine high activity, high selectivity, and low overpotential. Extensive surface reconstruction of metal catalysts under high productivity operating conditions (high current densities, reducing potentials, and variable pH) renders the realization of tailored catalysts that maximize the exposure of the most favorable facets, the number of active sites, and the oxidation state all the more challenging. Earth‐abundant transition metals such as tin, bismuth, and lead have been proven stable and product‐specific, but exhibit limited partial current densities. Here, a strategy that employs bismuth oxyhalides as a template from which 2D bismuth‐based catalysts are derived is reported. The BiOBr‐templated catalyst exhibits a preferential exposure of highly active Bi () facets. Thereby, the CO2 reduction reaction selectivity is increased to over 90% Faradaic efficiency and simultaneously stable current densities of up to 200 mA cm?2 are achieved—more than a twofold increase in the production of the energy‐storage liquid formic acid compared to previous best Bi catalysts. 相似文献
17.
Pan Xiong Bing Sun Nobuyuki Sakai Renzhi Ma Takayoshi Sasaki Shijian Wang Jinqiang Zhang Guoxiu Wang 《Advanced materials (Deerfield Beach, Fla.)》2020,32(18):1902654
2D genuine unilamellar nanosheets, that are, the elementary building blocks of their layered parent crystals, have gained increasing attention, owing to their unique physical and chemical properties, and 2D features. In parallel with the great efforts to isolate these atomic-thin crystals, a unique strategy to integrate them into 2D vertically stacked heterostuctures has enabled many functional applications. In particular, such 2D heterostructures have recently exhibited numerous exciting electrochemical performances for energy storage and conversion, especially the molecular-scale heteroassembled superlattices using diverse 2D unilamellar nanosheets as building blocks. Herein, the research progress in scalable synthesis of 2D superlattices with an emphasis on a facile solution-phase flocculation method is summarized. A particular focus is brought to the advantages of these 2D superlattices in applications of supercapacitors, rechargeable batteries, and water-splitting catalysis. The challenges and perspectives on this promising field are also outlined. 相似文献
18.
Jinlong Liu Yao Zheng Yan Jiao Zhenyu Wang Zhouguang Lu Anthony Vasileff Shi‐Zhang Qiao 《Small (Weinheim an der Bergstrasse, Germany)》2018,14(16)
Conventional development of nanomaterials for efficient electrocatalysis is largely based on performance‐oriented trial‐and‐error/iterative approaches, while a rational design approach at the atomic/molecular level is yet to be found. Here, inspired by a fundamental understanding of the mechanism for both oxygen and hydrogen evolution half reactions (OER/HER), a unique strategy is presented to engineer RuO2 for superior alkaline water electrolysis through coupling with NiO as an efficient bifunctional promoter. Benefitting from desired potential‐induced interfacial synergies, NiO‐derived NiOOH improves the oxygen binding energy of RuO2 for enhanced OER, and NiO also promotes water dissociation for enhanced HER on RuO2‐derived Ru. The resulting hybrid material exhibits remarkable bifunctional activities, affording 2.6 times higher OER activity than that of RuO2 and an HER activity comparable to Pt/C. As a result, the simple system requires only 1.5 V to deliver 10 mA cm?2 for overall alkaline water splitting, outperforming the benchmark PtC/NF||IrO2/NF couple with high mass loading. Comprehensive electrochemical investigation reveals the unique and critical role of NiO on the optimized RuO2/NiO interface for synergistically enhanced activities, which may be extended to broader (electro)catalytic systems. 相似文献