文献类型：期刊文献

英文题名：Weakened Interfacial Hydrogen Bond Connectivity Drives Selective Photocatalytic Water Oxidation toward H2O2 at Water/Brookite-TiO2 Interface

作者：Ren, Guanhua[1,2];Zhou, Min[1,2];Wang, Haifeng[1,2]

机构：[1]East China Univ Sci & Technol, Ctr Computat Chem, State Key Lab Green Chem Engn & Ind Catalysis, Shanghai 200237, Peoples R China;[2]East China Univ Sci & Technol, Res Inst Ind Catalysis, Shanghai 200237, Peoples R China

年份：2024

卷号：146

期号：9

起止页码：6084

外文期刊名：JOURNAL OF THE AMERICAN CHEMICAL SOCIETY

收录：;EI(收录号：20241015666885);WOS:【SCI-EXPANDED(收录号:WOS:001174417500001)】；

基金：This project was supported by National Key R&D Program of China (Grant 2021YFA1500700), NSFC (Grants 22202069 and 21873028), Special Support by the China Postdoctoral Science Foundation (Grant 2022TQ0106), the China Postdoctoral Science Foundation Funded Project (Grant 2022M721141), and the Fundamental Research Funds for the Central Universities.

语种：英文

外文关键词：Complexation - Crystal atomic structure - Excited states - Hydrogen bonds - Molecular dynamics - Oxide minerals - Phase interfaces - Reaction kinetics

摘要：The formation of H2O2 through the two-electron photocatalytic water oxidation reaction (WOR) is significant but encounters the competition with the four-electron O-2 evolution reaction. Recent studies showed a crystal-phase dependence in H2O2 selectivity, where high purity brookite TiO2 (b-TiO2) exhibits remarkable H2O2 selectivity in contrast to the common rutile phase TiO2 (r-TiO2). However, the origin of such a structure-induced selectivity preference remains elusive, primarily due to the complexities associated with the solid-liquid interface system and excited-state chemistry. Herein, we conducted a comprehensive investigation into the selectivity mechanism of WOR at the water/b-TiO2(210) and water/r-TiO2(110) interfaces, employing first-principles molecular dynamics simulations and microkinetic analyses. Intriguingly, our results reveal that the intrinsic catalytic ability of the b-TiO2(210) itself does not enhance H2O2 selectivity compared to r-TiO2(110). Instead, it is the weakened interfacial hydrogen bond connectivity, modulated by the herringbone-like local atomic structure of the b-TiO2(210) surface, that determines the selectivity. Specifically, this weakened H-bond connectivity (i.e., local low water density) at the interface, owing to the strong water adsorption and distinct adsorption orientation, can stabilize the OH center dot radical and inhibit its deprotonation, leading to an improved H2O2 selectivity. By contrast, the relatively strong interface H-bond connectivity established over r-TiO2(110) accelerates the deprotonation of OH center dot, with the OH center dot coverage being 3 orders of magnitude lower than at the water/b-TiO2(210) interface. This study quantitatively demonstrates that the local H-bond structure (water density) at the liquid/solid interface significantly influences photocatalytic selectivity, and this insight may offer a rational approach to enhance the H2O2 selectivity.