School of Chemistry and Chemical Engineering/Institute of Clean Energy and Materials/Guangzhou Key Laboratory for Clean Energy and Materials/Huangpu Hydrogen Innovation Center, Guangzhou University, Guangzhou Higher Education Mega Center No. 230 Wai Huan Xi Road, Guangzhou, 510006, P. R. China.
College of Chemistry and Chemical Engineering, Central South University, Changsha, 410083, P. R. China.
Adv Mater. 2022 Dec;34(50):e2208438. doi: 10.1002/adma.202208438. Epub 2022 Nov 7.
The interaction mechanism between the reacting species and the active site of α-Fe O -based photoanodes in photoelectrochemical methanol conversion reaction is still ambiguous. Herein, a simple two-step strategy is demonstrated to fabricate a porous α-Fe O /CoFe O heterojunction for the methanol conversion reaction. The influence of the electronic structure of active site and interfacial effect on the reaction are investigated by constructing two different FeO octahedral configurations and heterogeneous structures. The optimal sample ZnFeCo-2 affords high photocurrent density of 1.17 mA cm at 0.5 V vs Ag/AgCl, which is 3.2 times than that of ZnFe (0.37 mA cm ). Meanwhile, the ZnFeCo-2 also exhibits 97.8% Faraday efficiency of CH OH to HCHO, and long-term stability over 40 h. Furthermore, density functional theory calculations reveal that the heterostructured α-Fe O /CoFe O with favorable electron transfer effectively lowers methanol adsorption, C-H bond activation, and HCHO desorption energy relative to the pristine α-Fe O , resulting in excellent methanol conversion efficiency.
在光电化学甲醇转化反应中，反应物质与α-FeO 基光阳极活性位之间的相互作用机制仍不明确。本文采用一种简单的两步策略，制备了多孔α-FeO/CoFeO 异质结用于甲醇转化反应。通过构建两种不同的 FeO 八面体构型和异质结构，研究了活性位的电子结构和界面效应对反应的影响。优化后的样品 ZnFeCo-2 在 0.5 V vs Ag/AgCl 时提供了 1.17 mA cm 的高光电流密度，是 ZnFe（0.37 mA cm ）的 3.2 倍。同时，ZnFeCo-2 对 CH OH 到 HCHO 的法拉第效率也高达 97.8%，并且具有超过 40 h 的长期稳定性。此外，密度泛函理论计算表明，具有良好电子转移能力的异质结构α-FeO/CoFeO 有效降低了甲醇吸附、C-H 键活化和 HCHO 脱附能，从而实现了优异的甲醇转化效率。
