Im Eunmi, Park Seonhwa, Hwang Geon-Tae, Hyun Dong Choon, Min Yuho, Moon Geon Dae
Dongnam Regional Division, Korea Institute of Industrial Technology, Busan, 46938, South Korea.
School of Materials Science and Engineering, Kyungpook National University, Daegu, 41566, South Korea.
Small. 2024 Jan;20(1):e2304360. doi: 10.1002/smll.202304360. Epub 2023 Aug 30.
Developing single-crystal-based heterostructured ferroelectrics with high-performance photo-piezocatalytic activity is highly desirable to utilize large piezopotentials and more reactive charges that can trigger the desired redox reactions. To that end, a single-crystal-based (K,Na)NbO (KNN) microcuboid/CuO nanodot heterostructure with enhanced photo-piezocataytic activity, prepared using a facile strategy that leveraged the synergy between heterojunction formation and an intense single-crystal-based piezoelectric effect, is reported herein. The catalytic rhodamine B degrading activity of KNN/CuO is investigated under light irradiation, ultrasonication, or co-excitation with both stimulations. Compared to polycrystalline KNN powders and bare KNN single-crystals, single-crystal-based KNN/CuO exhibits a higher piezocurrent density and an optimal energy band structure, resulting in 5.23 and 2.37 times higher piezocatalytic degradation activities, respectively. Furthermore, the maximum photo-piezocatalytic rate constant (≈0.093 min ) of KNN/CuO under 25 min ultrasonication and light irradiation is superior to that of other KNN-based catalysts, and 1.6 and 48.6 times higher than individual piezocatalytic and photocatalytic reaction rate constants, respectively. The excellent photo-piezocatalytic activity is attributed to the enhanced charge-carrier separation and proper alignment of band structure to the required redox levels by the appropriate p-n heterojunction and high piezoelectric potential. This report provides useful insight into the relationships between heterojunctions, piezoelectric responses, and catalytic mechanisms for single-crystal-based heterostructured catalysts.
开发具有高性能光压电催化活性的单晶基异质结构铁电体，对于利用大的压电势和更多能引发所需氧化还原反应的活性电荷非常有必要。为此，本文报道了一种基于单晶的(K,Na)NbO (KNN)微立方块/CuO纳米点异质结构，其通过利用异质结形成与强烈的单晶基压电效应之间的协同作用的简便策略制备，具有增强的光压电催化活性。在光照射、超声处理或两种刺激共同激发下，研究了KNN/CuO对罗丹明B的催化降解活性。与多晶KNN粉末和裸KNN单晶相比，基于单晶的KNN/CuO表现出更高的压电电流密度和最佳的能带结构，导致压电催化降解活性分别提高5.23倍和2.37倍。此外,在超声处理25分钟和光照射下，KNN/CuO的最大光压电催化速率常数(≈0.093 min)优于其他基于KNN的催化剂，分别比单独的压电催化和光催化反应速率常数高1.6倍和48.6倍。优异的光压电催化活性归因于通过适当的p-n异质结和高压电势增强了电荷载流子的分离以及能带结构与所需氧化还原水平的适当匹配。本报告为单晶基异质结构催化剂的异质结、压电响应和催化机制之间的关系提供了有用的见解。
