Efficient design principle for interfacial charge separation in hydrogen-intercalated nonstoichiometric oxides
By Gu, Zhenao; Zhang, Le; Wen, Bo; An, Xiaoqiang; Lan, Huachun; Liu, Li-Min; Chen, Tao; Zhang, Jing; Cao, Xingzhong; Tang, Junwang; Liu, Huijuan; Qu, Jiuhui
Published in Nano Energy
2018
Abstract
Establishing effective strategies to boost the separation of interfacial charge carriers is necessary to address the limiting bottlenecks of photocatalysis. Although oxygen vacancy modulation has become the prevalent strategy to improve the photoactivity, controversy persists regarding the real role of these defects in charge separation. To exert the great potential of nonstoichiometric semiconductors, one needs not only to establish a full atomistic picture of oxygen vacancies, but also to deliberate their possible interactions with other interfacial structures (represented by the ubiquitous intercalated hydrogen). Herein, WO3 was used as a typical model to demonstrate the principle of hydrogen-intercalated nonstoichiometric oxides for photoelectrochemical water splitting. Both experimental characterizations and theoretical calculations evidenced the synergetic interactions between oxygen vacancies and intercalated hydrogen. The sequential formation of subsurface defect clusters and surface O