A Delaminated Defect-Rich ZrO2 Hierarchical Nanowire Photocathode for Efficient Photoelectrochemical Hydrogen Evolution

作者：Rahman Md Anisur; Thomas Joseph P; Leung Kam Tong

来源：Advanced Energy Materials, 2018, 8(4): 1701234.

DOI：10.1002/aenm.201701234

• nanostructured photocathodes
• oxygen vacancy defects
• p-type zirconium dioxides
• transparent conductive oxides
• visible-light-driven photoelectrochemical water splitting

An efficient way to combat the energy crisis and the greenhouse gas effect of fossil fuels is the production of hydrogen fuel from solar-driven water splitting reaction. Here, this study presents a p-type ZrO2 nanoplate-decorated ZrO2 nanowire photocathode with a high photoconversion efficiency that makes it potentially viable for commercial solar H-2 production. The composition of oxygen vacancy defects, low charge carrier transport property, and high specific surface area of these as-grown hierarchical nanowires are further improved by an hydrofluoric acid (HF) treatment, which causes partial delamination and produces a thin amorphous ZrO2 layer on the surface of the as-grown nanostructured film. The presence of different types of oxygen vacancies (neutral, singly charged, and doubly charged defects) and their compositional correlation to the Zrx+ oxidation states (4 > x > 2) are found to affect the charge transfer process, the p-type conductivity, and the photocatalytic activity of the ZrO2 nanostructured film. The resulting photocathode provides the highest overall photocurrent (-42.3 mA cm(-2) at 0 V vs reversible hydrogen electrode (RHE)) among all the photocathodes reported to date, and an outstanding 3.1% half-cell solar-to-hydrogen conversion efficiency with a Faradaic efficiency of 97.8%. Even more remarkable is that the majority of the photocurrent (69%) is produced in the visible light region.

• 出版日期2018-2-5