Hydrogen-Bond Network Promotes Water Splitting on the TiO2 Surface

• DOI: 10.1021/jacs.2c03690
• Publication Date: 2022-07-19T11:51:12Z
• Authors: Xiaochuan Ma; Yongliang Shi; Jianyi Liu; Xintong Li; Xuefeng Cui; Shijing Tan; Jin Zhao; Bing Wang
• Keywords: Titanium; Water; Hydrogen Bonding; Protons; 01 natural sciences; 0104 chemical sciences

Breaking the strong covalent O–H bond of an isolated H2O molecule is difficult, but it can be largely facilitated when connected with others through hydrogen-bonding. How a hydrogen-bond network forms and performs becomes crucial for water splitting in natural photosynthesis artificial photocatalysis awaiting microscopic spectroscopic understanding at molecular level. At prototypical photocatalytic H2O/anatase-TiO2(001)-(1×4) interface, we report promote coupled proton hole transfer splitting. The formation controlled by precisely tuning coverage to above one monolayer. Under ultraviolet (UV) light irradiation, opens cascaded channel photoexcited hole, concomitant release form surface hydroxyl groups. yielded groups provide excess electrons TiO2 surface, causing reduction Ti4+ Ti3+ leading emergence gap states, as monitored situ UV/X-ray photoelectron spectroscopy. density functional theory calculation reveals that exothermic process oxidation assistance network. In addition widely concerned exotic activity from photocatalysts, our study demonstrates internal network, which ubiquitous practical aqueous/catalyst interfaces, also indispensable