Transition metal single atoms anchoring VTe2 for efficient overall water splitting and oxygen reduction reactions: A first principles study

Cost-effective and high surface free energy are the advantages of single atom catalysts (SAC), but higher surface free energy produces nanoclusters and reduced catalytic activity. Herein, through the calculation based on first principles, transition metals (TM) anchored in VTe2 electrolytic water catalysts have been designed. Te atom with strong electronegativity and TM atom with catalytic activity form strong covalent bond, which makes TM atom have better catalytic activity and stability. The calculation results show that Cr@VTe2 and Fe@VTe2 have good catalytic activity for HER with overpotential is 0.180 V and 0.176 V, respectively, which is about 60% lower than the original VTe2. Ni@VTe2 has excellent catalytic performance for OER with an overpotential of 0.34 V, which is about 60% lower than the original VTe2. Fe@VTe2 and Ni@VTe2 showed significant catalytic activity to ORR, superior to the benchmark catalyst Pt. Notably, Fe@VTe2 is considered to be an effective electrocatalyst for HER and ORR, while Ni@VTe2 is considered to be an effective electrocatalyst for OER and ORR. Excitingly, Fe@VTe2 is expected to be a three-functional catalyst for HER, OER and ORR under certain conditions. This work provides theoretical support for the practical application of cost-effective VTe2 based catalysts for water electrolysis.