The electrochemical HER measurements were performed in a typical threeelectrode system by using a CHI 604E electrochemical workstation, in which a Ag/AgCl electrode acts as the reference electrode, pristine TiO2/TM or Vo-TiO2/TM as the working electrode and platinum sheet as the counter electrode, respectively. All experiments were conducted at room temperature. The exposed active area for electrocatalysis was 1.0 cm×1.0 cm, and linear-sweep voltammetry (LSV) was recorded at a scan rate of 5 mV•s -1 in acidic electrolyte (0.1 M H2SO4).