Currently, two-dimensional transition metal dichalcogenides (2D TMDs) materials have attracted extensive attention in the field of catalysis due to their unique atomic configuration and electronic structure, especially in the field of electrocatalytic hydrogen evolution reaction. For example, 2D TMDs electrocatalysts are reported to possess enhanced HER performance than that of commercial benchmark Pt/C catalyst at high current densities. It is worth noting that the active sites of 2D TMDs materials reported in the literature are generally unsaturated coordination atoms at the edge. However, the saturated coordinative atoms in the 2D TMDs surface base planes do not participate in the construction of catalytic active sites, losing the advantage of high specific surface areas of 2D materials to some extent. Thus, several strategies, including defect engineering, surface modification, and phase transition,have been proposed to increase the number of active sites on the 2D TMDs base planes. However, currently reported strategies to control the basal surface activity of 2D materials require the use of noble metals or complicated preparation methods, which will undoubtedly increase the cost of catalysts. Therefore, seeking a facile and economical defect engineering strategy on 2D electrochemical catalysts is of great importance.
Recently, Professor Yanguang Li of our institute, together with other researchers have prepared a new type of Frenkel-defected structure on the monolayer MoS2 (FD-MoS2) basal plane for the first time, which exhibits excellent catalytic performance in the electrocatalytic hydrogen evolution reaction. In this work, we demonstrate the atomic structure of the classic Frenkel defect in textbooks for the first time through aberration-corrected scanning transmission electron microscopy (AC-STEM). Micro-reactor electrochemical evaluation shows a significantly enhanced HER activity of the FD-MoS2 catalyst, of which the overpotential at the current density of 10 mA cm-2 is 164 mV, much lower than those of the reference Pt-single-atom doped monolayer MoS2 plane (211 mV) and the pristine monolayer MoS2 plane (358 mV). Finally, density functional theory calculation reveals the unique charge distribution and H adsorption sites introduced by the Frenkel defects in MoS2. These findings highlight the advantages of Frenkel defects in tuning the HER performance of 2D materials for outperforming Pt single-atom doped 2D catalysts.
The first author Dr. Jie Xu is from FUNSOM, Soochow University.
Link to Paper: https://www.nature.com/articles/s41467-022-29929-7
Link to Prof. Li’s group: http://www.ligroup.com.cn/
Acknowledgement: We acknowledge the financial support from National Natural Science Foundation of China (51971157, 21975067, and 22175060), Natural Science Foundation of Jiangsu Province of China (BK20210729), Tianjin Science Fund for Distinguished Young Scholars (19JCJQJC61800), Shanghai Rising-star Program (20QA1402400), the Program for Professor of Special Appointment (Eastern Scholar) at Shanghai Institutions of Higher Learning, and Fundamental Research Funds for the Central Universities from East China University of Science and Technology and Hunan University. J.X. and Y.L. acknowledge Suzhou Key Laboratory of Functional Nano & Soft Materials, Collaborative Innovation Center of Suzhou Nano Science & Technology, the 111 Project and Joint International Research Laboratory of Carbon-Based Functional Materials and Devices. J.X. also acknowledges the support from Excellent Youth Scholars Program of Soochow University.
Editor: Guo Jia