School of Chemical Engineering, The University of Queensland, Brisbane, 4072, Australia.
School of Natural Sciences and Queensland Micro- and Nanotechnology Centre, Griffith University, Nathan Campus, 4111, Australia.
Adv Mater. 2017 May;29(17). doi: 10.1002/adma.201606793. Epub 2017 Feb 27.
Electrochemical water splitting is a promising method for storing light/electrical energy in the form of H fuel; however, it is limited by the sluggish anodic oxygen evolution reaction (OER). To improve the accessibility of H production, it is necessary to develop an efficient OER catalyst with large surface area, abundant active sites, and good stability, through a low-cost fabrication route. Herein, a facile solution reduction method using NaBH as a reductant is developed to prepare iron-cobalt oxide nanosheets (Fe Co -ONSs) with a large specific surface area (up to 261.1 m g ), ultrathin thickness (1.2 nm), and, importantly, abundant oxygen vacancies. The mass activity of Fe Co -ONS measured at an overpotential of 350 mV reaches up to 54.9 A g , while its Tafel slope is 36.8 mV dec ; both of which are superior to those of commercial RuO , crystalline Fe Co -ONP, and most reported OER catalysts. The excellent OER catalytic activity of Fe Co -ONS can be attributed to its specific structure, e.g., ultrathin nanosheets that could facilitate mass diffusion/transport of OH ions and provide more active sites for OER catalysis, and oxygen vacancies that could improve electronic conductivity and facilitate adsorption of H O onto nearby Co sites.
电化学水分解是一种将光/电能以 H 燃料形式存储的有前途的方法；然而，它受到阳极析氧反应 (OER) 缓慢的限制。为了提高 H 生产的可及性，有必要通过低成本制造路线开发具有大表面积、丰富活性位点和良好稳定性的高效 OER 催化剂。在此，开发了一种使用 NaBH 作为还原剂的简便溶液还原法来制备具有大比表面积（高达 261.1 m g ）、超薄厚度（1.2 nm）的铁钴氧化物纳米片（FeCo-ONSs），并且重要的是，具有丰富的氧空位。在 350 mV 过电势下测量的 FeCo-ONS 的质量活性高达 54.9 A g ，而其塔菲尔斜率为 36.8 mV dec ；这两者都优于商业 RuO 、结晶 FeCo-ONP 和大多数报道的 OER 催化剂。FeCo-ONS 优异的 OER 催化活性可归因于其特殊结构，例如超薄纳米片可以促进 OH 离子的质量扩散/传输，并为 OER 催化提供更多的活性位点，以及氧空位可以提高电子导电性并促进 H 2 O 吸附到附近的 Co 位上。
