Rapid Hydroxyl Radical Generation on (001)-Facet-Exposed Ultrathin Anatase TiO 2 Nanosheets for Enhanced Photocatalytic Lignocellulose-to-H 2 Conversion

作者：Quan Cheng, Yongjun Yuan, Rui Tang, Qing‐Yu Liu, Liang Bao, Pei Wang, Jiasong Zhong, Zong‐Yan Zhao, Zhen‐Tao Yu, Zhigang Zou · 发表于：ACS Catalysis · 年份：2022 · DOI：10.1021/acscatal.1c05713 · 被引用次数：187 · 研究领域：Advanced Photocatalysis Techniques、TiO2 Photocatalysis and Solar Cells、Nanomaterials for catalytic reactions

Photocatalytic lignocellulose-to-H 2 conversion is highly attractive but remains a huge challenge due to the absence of efficient photocatalysts. Herein we report the use ultrathin anatase TiO 2 nanosheets with a thickness of 2.1 nm and 94.5% exposed (001) facets (TiO 2 -1) as highly active photocatalysts for photocatalytic lignocellulose-to-H 2 conversion. The ultrathin structure of TiO 2 not only provides abundant active sites for the photocatalytic H 2 production reaction but also benefits photogenerated charge transfer to the surface. Furthermore, as proven by theoretical calculations and fluorescence experiments, the ● OH radicals acting as the key species for the oxidation of lignocelluloses can be easily generated on the (001) facets owing to the low activating energy for the ● OH generation reaction. Notably, the highest photocatalytic H 2 generation rates of 275 and 26 μmol·h –1 ·g –1 were achieved, respectively, in 250 mL of 4g·L –1 α-cellulose solution and poplar wood chip aqueous solution consisting of 100 mg of 1.0% Pt-loaded TiO 2 -1 photocatalyst, and an apparent quantum yield of 1.89% at 380 nm was achieved in α-cellulose aqueous solution. The photocatalytic H 2 production activity of TiO 2 -1 is about 2.4 and 2.1 times higher than that of reference TiO 2 nanosheets (TiO 2 -2) in α-cellulose solution and poplar wood chip solution, respectively. Our findings demonstrate the feasibility of establishing rapid ● OH generation to boost the oxidation of lignocellulo...