Zhang Wang, Li Rui, Zhao Xin, Chen Zhong, Law Adrian Wing-Keung, Zhou Kun
Environmental Process Modelling Centre, Nanyang Environment and Water Research Institute, Nanyang Technological University, Singapore, 637141, Singapore.
School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore, 639798, Singapore.
ChemSusChem. 2018 Aug 22;11(16):2710-2716. doi: 10.1002/cssc.201801162. Epub 2018 Jul 19.
A metal-organic framework (MOF)-modified bismuth vanadate (BiVO ) photoanode is fabricated by an ultrathin sheet-induced growth strategy, where ultrathin cobalt oxide sheets act as a metal source for the in situ synthesis of Co-based MOF poly[Co (benzimidazole) ] (denoted [Co (bim) ]) nanoparticles on the surface of BiVO . [Co (bim) ] with small particle size and high dispersion can serve as a promising cocatalyst to accept holes transferred from BiVO and boost surface reaction kinetics for photoelectrochemical (PEC) water oxidation. The photocurrent density of a [Co (bim) ]-modified BiVO photoanode can achieve 3.1 mA cm under AM 1.5G illumination at 1.23 V versus the reversible hydrogen electrode (RHE), which is better than those of pristine and cobalt-based inorganic materials-modified BiVO photoanodes. [Co (bim) ], with porosity and abundant metal sites, exhibits a high surface charge-separation efficiency (83 % at 1.2 V versus RHE), leading to the enhanced PEC activity. This work will bring new insight into the development of MOF materials as competent cocatalysts for PEC water splitting applications.
采用超薄片诱导生长策略制备了一种金属有机框架（MOF）修饰的钒酸铋（BiVO₄）光阳极，其中超薄氧化钴片作为金属源，用于在BiVO₄表面原位合成钴基金属有机框架聚[Co(苯并咪唑)₃]（表示为[Co(bim)₃]）纳米颗粒。粒径小且分散性高的[Co(bim)₃]可作为一种有前景的助催化剂，接受从BiVO₄转移来的空穴，并促进光电化学（PEC）水氧化的表面反应动力学。在1.23 V（相对于可逆氢电极（RHE））的AM 1.5G光照下，[Co(bim)₃]修饰的BiVO₄光阳极的光电流密度可达3.1 mA cm⁻²，优于原始的和钴基无机材料修饰的BiVO₄光阳极。具有孔隙率和丰富金属位点的[Co(bim)₃]表现出高表面电荷分离效率（在1.2 V相对于RHE时为83%），从而提高了PEC活性。这项工作将为开发作为PEC水分解应用中有效助催化剂的MOF材料带来新的见解。
