清华大学朱永法团队报道了通过钨氧化物中的氧空位引导电子-空穴迁移路径提高其光催化析氧性能的策略。相关研究成果于2021年1月24日发表在《德国应用化学》。

   水分解的整体效率主要受到缓慢的析氧动力学的限制。因此，开发活性析氧催化剂是十分必要的。

   为此，研究人员设计并合成了一种含氧空位的钨氧化物光催化析氧催化剂，其析氧速率为683μmol·h^-1·g^-1，高于纯WO₃（159μmol·h^-1·g^-1）。随后通过瞬态吸收光谱研究发现，氧空位能产生电子俘获态，抑制光生载流子的直接复合。另外，Pt助催化剂可以促进电子俘获态参与反应，进一步提高光催化性能。

    该研究工作利用飞秒瞬态吸收光谱解释了无机材料的光催化析氧机理，为高效水分解催化剂的设计提供了新的思路。

附：英文原文

Title: Steering electron‐hole migration pathways using oxygen vacancies in tungsten oxides to enhance their photocatalytic oxygen evolution performance

Author: Zhen Wei, Wenchao Wang, Wenlu Li, Xueqin Bai, Jianfeng Zhao, Edmund C. M. Tse, David Lee Phillips, Yongfa Zhu

Issue&Volume: 24 January 2021

Abstract: Overall water splitting efficiency is mainly restricted by the slow kinetics of oxygen evolution. Therefore, it is essential to develop active oxygen evolution catalysts. In this regard, we designed and synthesized a tungsten oxide catalyst with oxygen vacancies for photocatalytic oxygen evolution, which exhibited a higher oxygen evolution rate of 683 μmol·h  ‐1  ·g  ‐1  than that of pure WO  3  (159 μmol·h  ‐1  ·g  ‐1  ). Subsequent study through transient absorption spectroscopy found that the oxygen vacancies can produce electron trapping states to inhibit the direct recombination of photogenerated carriers. Additionally, a Pt cocatalyst can promote electron trapped states to participate in the reaction to improve the photocatalytic performance further. This work uses femtosecond transient absorption spectroscopy to explain the photocatalytic oxygen evolution mechanism of inorganic materials and provides new insights into the design of high‐efficiency water‐splitting catalysts.

DOI: 10.1002/anie.202016170

Source: https://onlinelibrary.wiley.com/doi/10.1002/anie.202016170