Modulation of electronic structure and oxygen vacancies of perovskites SrCoO_3-δ by sulfur doping enables highly active and stable oxygen evolution reaction

Resolving the energy crisis and advancing the commercialization of electrochemical conversion devices is urgent tasks nowadays. Developing cost-effective electrocatalysts for oxygen evolution reaction (OER) is of foremost importance for these electrochemical conversion devices. Herein, we developed a non-metallic and cost-effective sulfur-doped SrCoO_3-δ perovskite electrocatalyst, namely SrCoO_3-xS_x (x = 0.02, 0.04, 0.06, 0.08 and 0.1, denoted as SCS2, SCS4, SCS6, SCS8 and SCS10, respectively) for water splitting in alkaline solution. Sulfur doping results in a structural change of SrCoO_3-δ perovskite from hexagonal to cubic perovskite. The electrochemical performance of this catalyst indicates that an optimal sulfur doping could enhance the conductivity of SrCoO_3-δ, resulting in a remarkable improvement on OER activity. The DFT calculation also confirm S doping can improve the electron conduction by lowering the activation energy of electron conductivity. Moreover, the doped SrCoO_3-xS_x also show enhanced durability due to the stable cubic structure with sulfur substitution. This work offers an inexpensive doping strategy for SrCoO_3-δ perovskite as an efficient electrocatalyst for the enhanced electrochemical performance of OER activity in water splitting.