Regulating the Electronic Structure of Ruddlesden-Popper-Type Perovskite by Chlorine Doping for Enhanced Oxygen Evolution Activity.

ABSTRACT

Developing economical, efficient, and durable oxygen evolution catalysts is crucial for achieving sustainable energy conversion and storage. Ruddlesden-Popper-type perovskite oxides are at the forefront of oxygen evolution reaction (OER) research. However, their activity and stability are far from satisfactory. Therefore, we emphasize the paradigm shift in designing efficient perovskite-type OER catalysts through anion defect engineering. The Cl anion-doped A2BO4-type perovskite oxides, SrLaCoO4-xClx (SLCOClx), were employed as highly efficient OER catalysts, wherein Cl could tune the electronic structure of SrLaCoO4 (SLCO) to enhance the OER activity effectively. Especially, SLCOCl0.15 demonstrates significantly enhanced OER activity, and the overpotential is only 370 mV at 10 mA·cm-2, which is significantly better than that of SLCO (510 mV). As confirmed by experience results and density functional theory (DFT) calculation, due to the doping of Cl, obviously increasing the ratio of Co2+/Co3+, more abundant oxygen vacancies (O22-/O-) are generated, and the electrical conductivity is increased, which together promote the improvement of OER activity.