Enhancing the catalytic activity of CdX and ZnX (X = S, Se and Te) nanostructures for the hydrogen evolution reaction via transition metal doping

Abstract

Exploring stable and non-precious electrocatalysts for the hydrogen evolution reaction (HER) is the key to electrochemical water splitting. Herein, the catalytic activity of CdX and ZnX (X = S, Se and Te) nanostructures for the HER was systematically evaluated. Our calculations reveal that pristine CdX and ZnX (X = S, Se and Te) have a higher hydrogen adsorption free energy (ΔG_*H) in the range of 1.07–2.00 eV, indicating very weak *H adsorption and inefficient electrocatalytic activity for the HER. However, it is found that the HER activity of CdX and ZnX (X = S, Se and Te) nanostructures can be effectively enhanced by doping with transition metal (TM) atoms (Fe, Co, Ni, Cu, Pd and Pt). In particular, Ni-doped CdS and ZnTe, and Cu-doped CdSe, CdTe, ZnS and ZnSe have ΔG_*H values in the range of −0.03 to 0.09 eV, which is ideally near to zero, indicating their efficient catalytic activity. These results suggest that our work introduces Ni-doped CdS and ZnTe, and Cu-doped CdSe, CdTe, ZnS and ZnSe nanostructures as promising HER catalysts for future energy applications.