State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences , and Dalian National Laboratory for Clean Energy, The Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), Zhongshan Road 457, Dalian, 116023, China.
University of Chinese Academy of Sciences , Beijing 100049, China.
ACS Appl Mater Interfaces. 2017 Sep 13;9(36):30696-30702. doi: 10.1021/acsami.7b09021. Epub 2017 Sep 1.
Photoelectrochemical water splitting provides an attractive way to store solar energy in molecular hydrogen as a kind of sustainable fuel. To achieve high solar conversion efficiency, the most stringent criteria are effective charge separation and injection in electrodes. Herein, efficient photoelectrochemical water oxidation is realized by optimizing charge separation and surface charge transfer of GaN:ZnO photoanode. The charge separation can be greatly improved through modified moisture-assisted nitridation and HCl acid treatment, by which the interfaces in GaN:ZnO solid solution particles are optimized and recombination centers existing at the interfaces are depressed in GaN:ZnO photoanode. Moreover, a multimetal phosphide of NiCoFeP was employed as water oxidation cocatalyst to improve the charge injection at the photoanode/electrolyte interface. Consequently, it significantly decreases the overpotential and brings the photocurrent to a benchmark of 3.9 mA cm at 1.23 V vs RHE and a solar conversion efficiency over 1% was obtained.
光电化学水分解提供了一种将太阳能以分子氢的形式储存为可持续燃料的有吸引力的方法。为了实现高太阳能转换效率，最严格的标准是在电极中有效进行电荷分离和注入。在此，通过优化 GaN:ZnO 光阳极的电荷分离和表面电荷转移，实现了高效的光电化学水氧化。通过改进的水分辅助氮化和 HCl 酸处理，可以大大提高电荷分离，优化 GaN:ZnO 固溶体颗粒中的界面，并抑制 GaN:ZnO 光阳极界面处存在的复合中心。此外，采用多金属磷化物 NiCoFeP 作为水氧化助催化剂，以改善光阳极/电解质界面处的电荷注入。因此，它显著降低了过电位，并使光电流达到 1.23 V vs RHE 时的 3.9 mA cm 的基准值，并获得了超过 1%的太阳能转换效率。
