Li Xinnan, Tong Wangshu, Shi Jing, Zhang Xinyue, Chen Yunfan, Liu Xulin, Zhang Yihe
Engineering Research Center of Ministry of Education for Geological Carbon Storage and Low Carbon Utilization of Resources, Beijing Key Laboratory of Materials Utilization of Nonmetallic Minerals and Solid Wastes, National Laboratory of Mineral Materials, School of Materials Science and Technology, China University of Geosciences, Beijing 100083, China.
ACS Appl Mater Interfaces. 2024 Aug 14;16(32):42293-42304. doi: 10.1021/acsami.4c09206. Epub 2024 Aug 5.
Contact-electro-catalysis (CEC) usually uses polymer dielectrics as its catalysts under mechanical stimulation conditions, which although has a decent catalytic dye degradation effect still warrants performance improvement. A carrier separation promotion strategy based on an internal electric field by polarization can effectively improve ferroelectric material performance in photocatalysis and piezocatalysis. Therefore, carrier separation as a necessary process of CEC also can be promoted and is largely expected to improve CEC performance theoretically. However, the carrier separation enhancement by the internal electric field strategy has not been achieved in the CEC experiment yet, because of the difficulty of building an internal electric field in an inert polymer dielectric. Herein, a polytetrafluoroethylene (PTFE) dielectric was charged through an electret process, which was believed to establish an internal electric field for CEC catalysts proved by KPFM, XPS, and triboelectric nanogenerator voltage output analysis. The fastest degradation rate of methyl orange reached over 90% at 1.5 h, while the hydroxyl free radical (•OH) yield of the PTFE electret was nearly three times that of the original PTFE. Density functional theory (DFT) calculations verified that the potential barrier of interatomic electron transfer between PTFE and HO was reduced by 37% under the internal electric field. The electret strategy used herein to optimize the PTFE catalyst provides a base for the use of other general plastics in CEC and facilitates the production of easily prepared, easily recyclable, and inexpensive polymer dielectric catalysts that can promote large-scale pollutant degradation via CEC.
接触电催化（CEC）通常在机械刺激条件下使用聚合物电介质作为催化剂，尽管其具有不错的催化染料降解效果，但仍需提高性能。基于极化内电场的载流子分离促进策略可以有效提高铁电材料在光催化和压电催化中的性能。因此，作为CEC必要过程的载流子分离也可以得到促进，理论上有望大幅提高CEC性能。然而，由于在惰性聚合物电介质中构建内电场困难，内电场策略增强载流子分离在CEC实验中尚未实现。在此，通过驻极体过程对聚四氟乙烯（PTFE）电介质进行充电，通过开尔文探针力显微镜（KPFM）、X射线光电子能谱（XPS）和摩擦纳米发电机电压输出分析证明，这为CEC催化剂建立了内电场。甲基橙在1.5小时时的最快降解率达到90%以上，而PTFE驻极体的羟基自由基（•OH）产率几乎是原始PTFE的三倍。密度泛函理论（DFT）计算证实，在内部电场作用下，PTFE与HO之间的原子间电子转移势垒降低了37%。本文用于优化PTFE催化剂的驻极体策略为CEC中使用其他通用塑料提供了基础，并有助于生产易于制备、易于回收且廉价的聚合物电介质催化剂，这些催化剂可通过CEC促进大规模污染物降解。
