MXenes have exhibited great potential as cost-effective electrocatalysts for hydrogen evolution reaction(HER). However, insight into the origin of activity is still missing. Herein, on the basis of a systematical inve...MXenes have exhibited great potential as cost-effective electrocatalysts for hydrogen evolution reaction(HER). However, insight into the origin of activity is still missing. Herein, on the basis of a systematical investigation of the HER performance of 20 MXenes(M_2NO_2 and M_2CO_2, M = Sc, Ti, V, Cr, Zr, Nb, Mo,Hf, Ta and W), a Fermi-abundance model is proposed to understand variation of the activity in different MXenes. It is found that the occupied p electronic states of surface O atoms play a decisive role in the HER activity of MXenes. More importantly, Ti_2NO_2 and Nb_2NO_2 are found to be promising HER electrocatalysts with the free energy for hydrogen adsorption close to zero. This work not only provides possible catalysts for HER, the developed Fermi-abundance model but also is applicable to other two-dimensional materials and may serve as a simple descriptor of the intrinsic HER activity.展开更多
基金supported by the National Natural Science Foundation for Distinguished Young Scholar (21525311)the National Key R&D Program of China (2017YFA0204800)+3 种基金the National Natural Science Foundation of China (21773027, 21703032)Jiangsu 333 Project (BRA2016353)the Scientific Research Foundation of Graduate School of Southeast University in Chinathe Fundamental Research Funds for the Central Universities of China
文摘MXenes have exhibited great potential as cost-effective electrocatalysts for hydrogen evolution reaction(HER). However, insight into the origin of activity is still missing. Herein, on the basis of a systematical investigation of the HER performance of 20 MXenes(M_2NO_2 and M_2CO_2, M = Sc, Ti, V, Cr, Zr, Nb, Mo,Hf, Ta and W), a Fermi-abundance model is proposed to understand variation of the activity in different MXenes. It is found that the occupied p electronic states of surface O atoms play a decisive role in the HER activity of MXenes. More importantly, Ti_2NO_2 and Nb_2NO_2 are found to be promising HER electrocatalysts with the free energy for hydrogen adsorption close to zero. This work not only provides possible catalysts for HER, the developed Fermi-abundance model but also is applicable to other two-dimensional materials and may serve as a simple descriptor of the intrinsic HER activity.
