School of Materials Science and Engineering, UNSW Sydney, Sydney, NSW, 2052, Australia.
Institute Silicon Photovoltaics, Helmholtz-Zentrum Berlin, Berlin, 12489, Germany.
Adv Mater. 2019 Feb;31(8):e1807204. doi: 10.1002/adma.201807204. Epub 2019 Jan 7.
Conductive metal oxides represent a new category of functional material with vital importance for many modern applications. The present work introduces a new conductive metal oxide V O , which is synthesized via a simplified photoelectrochemical procedure and decorated onto the semiconducting photocatalyst BiVO in controlled mass percentages ranging from 25% to 37%. Owing to its excellent conductivity and good compatibility with oxide materials, the metallic V O -decorated BiVO hybrid catalyst shows a high photocurrent density of 2.2 ± 0.2 mA cm at 1.23 V versus reversible hydrogen electrode (RHE). Both experimental characterization and density functional theory calculations indicate that the superior photocurrent derives from enhanced charge separation and transfer, resulting from ohmic contact at the interface of mixed phases and superior electrical conductivity from V O . A Co-Pi coating on BiVO -V O further increases the photocurrent to 5.0 ± 0.5 mA cm at 1.23 V versus RHE, which is among the highest reported for BiVO -based photoelectrodes. Surface photovoltage and transient photocurrent measurements suggest a charge-transfer model in which photocurrents are enhanced by improved surface passivation, although the barrier at the Co-Pi/electrolyte interface limits the charge transfer.
导电金属氧化物是一类具有重要意义的新型功能材料，在许多现代应用中都有重要作用。本工作通过简化的光电化学程序合成了一种新型导电金属氧化物 V 2 O 5 ，并以 25%至 37%的可控质量比例负载在半导体光催化剂 BiVO 上。由于其优异的导电性和与氧化物材料的良好兼容性，金属 V 2 O 5 修饰的 BiVO 杂化催化剂在相对于可逆氢电极（RHE）为 1.23 V 时表现出 2.2±0.2 mA cm -2 的高光电流密度。实验表征和密度泛函理论计算均表明，优异的光电流源于混合相界面处欧姆接触增强的电荷分离和转移，以及 V 2 O 5 带来的优异导电性。在 BiVO-V 2 O 5 上涂覆 Co-Pi 进一步将光电流提高到相对于 RHE 为 1.23 V 时的 5.0±0.5 mA cm -2 ，这是基于 BiVO 的光电管中报道的最高值之一。表面光电压和瞬态光电流测量表明存在一种电荷转移模型，其中通过改善表面钝化来增强光电流，尽管 Co-Pi/电解质界面处的势垒限制了电荷转移。
