中科院大连化物所王峰团队报道了晶面依赖性电子转移调节生物多醇的光催化转化。相关研究成果发表在2022年11月9日出版的《美国化学会杂志》。

从半导体导带到表面结合物种的电子转移（ET）是光催化反应中的关键步骤，并强烈影响反应性和选择性，而由于缺乏有效的方法，很少探索催化剂表面结构对该过程的影响。

该文中，研究人员开发了一种检测和测量表面电子向吸附质转移能量的策略，并公开了锐钛矿型TiO₂上依赖于面的电子转移能量。光生电子以低于1.0eV的转移能量被浅限制在（101）面表面的五配位Ti原子（Ti5c）中，而以高于1.9eV的转移能深度限制在（001）面的亚表面上的六配位Ti原子（Ti6c）中。不同的电子陷阱状态强烈影响ET过程，从而调节光催化活性。

以甲酸（FA）脱水为探针反应，锐钛矿TiO₂（101）面上的光激发电子的浅陷阱有利于FA脱水为CO，而（001）面上光激发电子深陷阱使FA稳定。基于这一知识，研究人员成功地通过选择性地暴露TiO₂的晶面来控制生物多元醇的光催化氧化的选择性。通过控制（001）/（101）晶面，广泛的生物多元醇可以选择性地转化为FA或CO，选择性高达80%。

该研究公开了一种依赖于晶面的电子转移过程，并为光催化系统的设计提供了新的视野。

附：英文原文

Title: Facet-Dependent Electron Transfer Regulates Photocatalytic Valorization of Biopolyols

Author: Hongru Zhou, Min Wang, Fanhao Kong, Zhiwei Chen, Zhaolin Dou, Feng Wang

Issue&Volume: November 9, 2022

Abstract: The electron transfer (ET) from the conduction band of the semiconductor to surface-bound species is a key step in the photocatalytic reaction and strongly affects the reactivity and selectivity, while the effect of catalyst surface structure on this process has rarely been explored due to the lack of an effective method. Herein, we have developed a strategy to detect and measure surface electrons’ transfer energy to the adsorbates and disclosed a facet-dependent electron transfer energy over anatase TiO2. The photogenerated electrons are shallowly confined in the five-coordinated Ti atom (Ti5c) on the surface of the (101) facet with a transfer energy below 1.0 eV, while deeply confined in the six-coordinated Ti atom (Ti6c) on the subsurface of the (001) facet with a transfer energy higher than 1.9 eV. The different electron trap states strongly affect the ET process, thus regulating the photocatalytic activity. Taking formic acid (FA) dehydration as the probe reaction, a shallow trap of photoexcited electrons on the (101) facet of anatase TiO2 favors the dehydration of FA to CO, while a deep trap of photoexcited electrons on the (001) facet makes FA stable. Based on this knowledge, we successfully controlled the selectivity in the photocatalytic oxidation of biopolyols via selectively exposing the facet of TiO2. Through controlling the (001)/(101) facet, a wide range of biopolyols can be selectively converted into FA or CO with a selectivity of up to 80%. The present work disclosed a facet-dependent electron transfer process and provides a new horizon to the design of photocatalytic systems.

DOI: 10.1021/jacs.2c08655

Source: https://pubs.acs.org/doi/10.1021/jacs.2c08655