Piezocatalytic ZnS:Mn2+ nanocrystals for enhanced organic dye degradation
Zhongxiang Wang, Elizaveta Tiukalova, Youyi Tai, Miaofang Chi, Jin Nam, Yadong Yin
Abstract
Article Piezocatalytic ZnS: Mn2+ Nanocrystals for Enhanced Organic Dye Degradation Zhongxiang Wang 1, Elizaveta Tiukalova 2, Youyi Tai 3, Miaofang Chi 2, Jin Nam 3,* and Yadong Yin 1,* 1 Department of Chemistry, University of California, Riverside, CA 92521, USA 2 Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA 3 Department of Bioengineering, University of California, Riverside, CA 92521, USA * Correspondence: [email protected] (J.N.); [email protected] (Y.Y.) Received: 15 October 2024; Revised: 20 November 2024; Accepted: 21 November 2024; Published: 22 November 2024 Abstract: Piezocatalysis, an emerging approach that harnesses mechanical energy to drive chemical reactions, has garnered significant attention due to its potential applications in diverse fields, particularly in environmental remediation. Its broader application, however, is often hindered by the low efficiency of existing piezocatalytic materials. Here, we report the synthesis of Mn2+-doped ZnS nanocrystals with improved piezoelectric properties using an emulsion-based colloidal assembly technique. Through well-controlled Mn2+ doping, these nanocrystals demonstrate high piezocatalytic activity for degrading organic dyes under ultrasonic vibration. The optimal performance is achieved with 3% Mn2+ doping, outperforming many existing piezocatalysts. Mechanistic studies reveal the generation of reactive oxygen species as the primary driving force for degradation. Notably, pre-excitation with UV light further boosts the piezocatalytic efficiency of these metal ion-doped ZnS nanocrystals by filling electron trap states, leading to improved overall performance. This research paves the way for developing high-performance piezocatalysts, expanding the potential of piezocatalysis for a wide range of applications.