3D interconnected nanoporous TaN films for photoelectrochemical water splitting: thickness-controlled synthesis and insights into stability  

用于光电化学分解水的三维贯通纳米多孔Ta3N5薄膜:厚度调控与稳定性研究

作　　者：Qiang Wang Lingxia Zhang Bing Li Hongmin Zhu Jianlin Shi 王强;张玲霞;李冰;朱鸿民;施剑林(Department of Metallurgy,Graduate School of Engineering,Tohoku University,Sendai 980-8579,Japan;School of Mechanical and Power Engineering,East China University of Science and Technology,Shanghai 200237,China;State Key Lab of High Performance Ceramics and Superfine Microstructure,Shanghai Institute of Ceramics,Chinese Academy of Sciences,Shanghai 200050,China;School of Chemistry and Materials Science,Hangzhou Institute for Advanced Study,University of Chinese Academy of Sciences,Hangzhou 310024,China)

机构地区：[1]Department of Metallurgy,Graduate School of Engineering,Tohoku University,Sendai 980-8579,Japan [2]School of Mechanical and Power Engineering,East China University of Science and Technology,Shanghai 200237,China [3]State Key Lab of High Performance Ceramics and Superfine Microstructure,Shanghai Institute of Ceramics,Chinese Academy of Sciences,Shanghai 200050,China [4]School of Chemistry and Materials Science,Hangzhou Institute for Advanced Study,University of Chinese Academy of Sciences,Hangzhou 310024,China

出　　处：《Science China Materials》2021年第8期1876-1888,共13页中国科学（材料科学（英文版）

基　　金：financially supported by the National Natural Science Foundation of China (51774145,51872317 and 21835007);China Postdoctoral Science Foundation (2019M661644);China Scholarship Council (CSC) for financial support。

摘　　要：Solar-driven photoelectrochemical(PEC) water splitting is a promising technology for sustainable hydrogen production, which relies on the development of efficient and stable photoanodes for water oxidation reaction. The thickness and microstructure of semiconductor films are generally crucial to their PEC properties. Herein, three-dimensional(3D) interconnected nanoporous Ta3N5 film photoanodes with controlled thickness were successfully fabricated via galvanostatic anodization and NH3 nitridation. The porous Ta3N5 nanoarchitectures(NAs) of 900 nm in thickness showed the highest PEC performance due to the optimal lightharvesting and charge separation. Compared with the holeinduced photocorrosion, the electrochemical oxidation at high anodic potentials resulted in severer performance degradation of Ta3N5. Although the surface oxide layer on deteriorated Ta3N5 photoanodes could be removed by NH3 re-treatment,the PEC performance was only partially recovered. As an alternative, anchoring a dual-layer Co(OH)x/Co OOH co-catalyst shell on the porous Ta3N5 NAs demonstrated substantially enhanced PEC performance and stability. Overall, this work provides reference to controllably fabricate 3D nanoporous Ta3N5-based photoanodes for efficient and stable PEC water splitting via optimizing the light absorption, hole extraction,charge separation and utilization.太阳能光电化学分解水是一种理想的绿色制氢技术,而设计高效、稳定的光阳极是目前面临的最大挑战.考虑到薄膜厚度及其微观结构是影响光阳极性能的关键因素,本文采用恒电流阳极氧化-NH3氮化法制备出厚度精准可控的三维贯通多孔纳米Ta3N5薄膜光阳极.结果表明,Ta3N5厚度为900 nm时具有最高的光电解水性能,这源于其最优的光吸收和电荷分离效率.相比空穴自氧化,高偏压下的电化学氧化会造成更严重的性能衰减.NH3氮化可去除Ta3N5表面氧化层,但仅能部分恢复其性能,而原位负载的Co(OH)x/CoOOH双层助催化剂则显著提高了Ta3N5的光电化学性能及稳定性.本文提出通过厚度调控和表面修饰优化光吸收、空穴转移和电荷分离,为高效、稳定的纳米多孔Ta3N5基光阳极的可控制备提供了新策略.

关 键 词：Ta3N5 3D interconnected porous nanoarchitectures thickness-controlled synthesis photoelectrochemical water splitting PHOTOSTABILITY 

分 类 号：TM914.4[电气工程—电力电子与电力传动] TB383.2[一般工业技术—材料科学与工程]