Chen Chen, Zhao Siyu, Zhou Bingming, Ye Changqing, Jiang Baojiang, Zhang Liping
Faculty of Materials Science, Shenzhen MSU-BIT University, Shenzhen, Guangdong 518172, China.
Key Laboratory of Functional Inorganic Material Chemistry, Ministry of Education of the People's Republic of China, Heilongjiang University, Harbin, Heilongjiang 150080, China.
iScience. 2025 Mar 31;28(5):112327. doi: 10.1016/j.isci.2025.112327. eCollection 2025 May 16.
Mass transport is a fundamental yet often overlooked factor in influencing adsorption and photocatalytic reaction kinetics. This study examines the role of mass transport using the model system of monoclinic bismuth vanadate (BiVO) films and potassium dichromate (KCrO) in a representative photocatalytic reaction. We show that diffusion-driven delivery of KCrO to the BiVO surface increases adsorption capacity but decreases the adsorption rate constant. Notably, during the model photocatalytic reduction, long-range electric fields were observed around the illuminated BiVO films, a phenomenon also confirmed in a separate reaction system using TiO as the photocatalyst. These electric fields, distinct from the localized fields formed within heterojunctions, enhance dichromate transport by more than three orders of magnitude. This enhanced transport ensures a continuous supply of reactant to the photocatalyst, significantly improving reaction efficiency without additional energy input. These findings introduce a new strategy for optimizing photocatalytic processes, offering broad insights for advancing sustainable chemical engineering applications.
传质是影响吸附和光催化反应动力学的一个基本但常被忽视的因素。本研究使用单斜钒酸铋（BiVO）薄膜和重铬酸钾（KCrO）的模型体系，在一个具有代表性的光催化反应中研究传质的作用。我们表明，KCrO通过扩散驱动传递到BiVO表面会增加吸附容量，但会降低吸附速率常数。值得注意的是，在模型光催化还原过程中，在光照的BiVO薄膜周围观察到了长程电场，这一现象在另一个使用TiO作为光催化剂的反应体系中也得到了证实。这些电场不同于异质结内形成的局部电场，可将重铬酸盐的传输增强三个多数量级。这种增强的传输确保了反应物向光催化剂的持续供应，在无需额外能量输入的情况下显著提高了反应效率。这些发现引入了一种优化光催化过程的新策略，为推进可持续化学工程应用提供了广泛的见解。
