(AGENPARL) – LONDON (UNITED KINGDOM), gio 01 ottobre 2020
Compared to high-active anatase TiO2, rutile TiO2 usually represents poor photocatalytic performance due to high electron-hole recombination. Herein, we propose a surface domain heterojunction (SDH) structure between adjacent micro-domains with and without chemisorbed chlorine on rutile TiO2, which utilizes diverse domains potential difference to form build-in field for promoting charge separation. Single-crystal rutile TiO2 nanorods assembled radial microspheres with SDHs are fabricated and exhibit excellent solar-driven photocatalytic hydrogen evolution, ~8-fold higher than that of pristine one. Experimental results and density functional theory calculations reveal that the exceptional photocatalytic performance attributes to in-situ formation of chemisorbed chlorine, which forms SDHs to separate electron-hole efficiently, and results in surface reconfiguration to expose tri-active sites, increasing O sites active centers and enhancing 4-coordinated (Ti4c) and 5-coordinated Ti sites (Ti5c) catalytic activity. This SDH strategy could extend to other halogen elements, which provides universal approach for rational-design high-efficient TiO2 photocatalysts toward sustainable solar-fuel evolution.
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