Wei Peicheng, Lin Kaifeng, Meng Dedong, Xie Tengfeng, Na Yong
School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin, 150001, P.R. China.
College of Chemistry, Jilin University, Changchun, 130012, P.R. China.
ChemSusChem. 2018 Jun 11;11(11):1746-1750. doi: 10.1002/cssc.201800705. Epub 2018 May 22.
A WO /TiO heterojunction photoanode was prepared by in situ growth of WO on a mesoporous TiO electrode. The photoinduced charge-transfer properties and chargeseparation improvement in this kind of type-II heterojunction were characterized by transient surface photovoltage spectra. By using sulfite oxidation as a hole scavenger, we demonstrated that 72 % of the photo-generated holes are reaching the surface of the photoanode, but the efficiency of hole injection (η ) into the electrolyte was only 48 %. For the first time, a Ni meso-tetra(4-carboxyphenyl)porphyrin (NiTCPP) was incorporated as a water oxidation catalyst into the WO /TiO heterojunction photoanode, which promoted the value of η to 81 %. The maximum applied bias photon-to-current efficiency for the WO /TiO /NiTCPP photoanode was determined to be 0.2 % at 1.01 V vs. the reversible hydrogen electrode (RHE), under which condition a Faradic efficiency of 89 % for water oxidation was achieved (averaged over 1 h of photolysis).
通过在介孔TiO电极上原位生长WO制备了WO/TiO异质结光阳极。利用瞬态表面光电压谱表征了这种II型异质结中的光生电荷转移特性和电荷分离改善情况。通过使用亚硫酸盐氧化作为空穴清除剂，我们证明了72%的光生空穴到达了光阳极表面，但空穴注入到电解质中的效率（η）仅为48%。首次将镍中四（4-羧基苯基）卟啉（NiTCPP）作为水氧化催化剂掺入到WO/TiO异质结光阳极中，这使得η值提高到了81%。在相对于可逆氢电极（RHE）为1.01 V的条件下，WO/TiO/NiTCPP光阳极的最大外加偏压光子到电流效率测定为0.2%，在此条件下实现了水氧化的法拉第效率为89%（在1小时光解过程中平均）。
