Dual-cation-doped MoS <sub>2</sub> nanosheets accelerating tandem alkaline hydrogen evolution reaction
Hangfei Li, Yu Fan, Xin Ling, Haopeng Wan, Minhua Zhang, Yuxue Zhou, Jumeng Wei, Fei Lu, Xiuyun Zhang, Xianghua Zeng, Min Zhou
Abstract
Abstract Molybdenum disulfide (MoS 2 ) nanosheets are promising candidates as earth-abundant and low-cost catalyst for hydrogen evolution reaction (HER). Nevertheless, compared with the benchmark Pt/C catalyst, the application of MoS 2 nanosheets is limited to its relatively low catalytic activity, especially in alkaline environments. Here, we developed a dual-cation doping strategy to improve the alkaline HER performance of MoS 2 nanosheets. The designed Ni, Co co-doped MoS 2 nanosheets can promote the tandem HER steps simultaneously, thus leading to a much enhanced catalytic activity in alkaline solution. Density functional theory calculations revealed the individual roles of Ni and Co dopants in the catalytic process. The doped Ni is uncovered to be the active site for the initial water-cleaving step, while the Co dopant is conducive to the H desorbing by regulating the electronic structure of neighboring edge-S in MoS 2 . The synergistic effect resulted by the dual-cation doping thus facilitates the tandem HER steps, providing an effective route to raise the catalytic performance of MoS 2 materials in alkaline solution.