Electron strain-driven phase transformation in transition-metal-co doped MoTe2 for electrocatalytic hydrogen evolution

Abstract The phase engineering of transition metal tellurides is a promising method for the regulation of chemical bonding and electronic configuration, which plays a significant role in the design of efficient catalysts for hydrogen evolution reactions. The metallic phase of MoTe2 has been reported to reveal prominent electrocatalytic performance over the semiconductor phase. The comprehensive first-principle calculations indicated that the depth charge transfer induced by the Co-Ni metallic bi-doping better facilitated the phase transition than those corresponding to specific mono-metallic doping. Based on the above principle, a series of Co and Ni co-doping MoTe2 (Co,Ni-MoTe2) nanofilms with different doping concentrations were successfully deposited by the magnetron sputtering technique. Under the synergistic effects of electron injection and strain, Co,Ni-MoTe2 possessed a considerable 1T’ phase. The Co,Ni-MoTe2 films exhibited a remarkable overpotential of 10 mA cm–2 for HER at –82 mV, and the active sites promoted catalytic performance as confirmed by the computational modeling.