中国科学技术大学团队设计了一种Bi2O2CO3纳米片中再生氧空位引发的超稳定高效可见光驱动CO2还原的策略。相关研究成果于2021年3月30日发表在《德国应用化学》。

表面空位可以对CO2光还原活性产生积极影响，但很难维持其长期稳定性。

该文中，研究人员首次设计了一种快速的低压紫外光照射策略，可以很容易地再生几乎相等的表面空位，从而同时优化CO2光还原活性和稳定性。以含缺陷Bi2O2CO3纳米片为例，在紫外光照射下可以再生出几乎相等数量的氧空位。同步辐射准原位X射线光电子能谱揭示了O缺陷Bi2O2CO3纳米片中的Bi位可以作为高活性位，不仅有助于活化CO2分子，而且有助于稳定限速COOH*中间体。同时，原位傅里叶变换红外光谱和原位质谱揭示了紫外光照射有助于加速CO解吸过程。

结果表明，在110次循环试验中，O缺陷Bi2O2CO3纳米片的稳定性高达2640h，可见光驱动CO2还原为CO的转化率高达275μmol g1 h1。

该研究为开发可持续的CO2还原光催化剂提供了一条新途径。

附：英文原文

Title: Ultrastable and Efficient Visible‐light‐driven CO2 Reduction Triggered by Regenerative Oxygen‐vacancies in Bi2O2CO3 Nanosheets

Author: Yongfu Sun, Xiaolong Zu, Yuan Zhao, Xiaodong Li, Runhua Chen, Weiwei Shao, Zhiqiang Wang, Jun Hu, Junfa Zhu, Yang Pan, Yi Xie

Issue&Volume: 2021-03-30

Abstract: Surface vacancies can exert positive impact on CO2 photoreduction activity, yet difficultly maintaining long‐term stability. Herein, we first design a fast low‐pressure ultraviolet light irradiation strategy for easily regenerating the nearly equivalent surface vacancies, thus concurrently optimizing CO2 photoreduction activity and stability. Taking the defective Bi2O2CO3 nanosheets as an example, nearly equal amount of oxygen vacancies can be regenerated under UV light irradiation. Synchrotron‐radiation quasi in‐situ X–ray photoelectron spectra disclose the Bi sites in the O‐defective Bi2O2CO3 nanosheets can act as the highly active sites, which not only help to activate CO2 molecules, but also contribute to stabilizing the rate‐limiting COOH* intermediate. Also, in‐situ Fourier transform infrared spectroscopy and in‐situ mass spectrometry unravel the UV light irradiation contributes to accelerating CO desorption process. As a result, the O‐defective Bi2O2CO3 nanosheets achieve a stability up to 2640 h over 110 cycling tests and a high evolution rate of 275 μmol g1 h1 for visible‐light‐driven CO2 reduction to CO. This study offers a new way for developing sustainable CO2 reduction photocatalysts.

DOI: 10.1002/anie.202101894

Source: https://onlinelibrary.wiley.com/doi/10.1002/anie.202101894