Defect Passivation of Mn²⁺‐Doped CsPbX₃(X=Cl,Br) Perovskite Nanocrystals as Electrocatalyst for Overall Water Splitting

Abstract

Mn:CsPbX3 (X= Cl, Br) nanosheets with excellent electrocatalytic properties are reported in this paper. Compared to conventional catalyst arrays, the band gap of Mn:CsPbBr3 nanocrystalline is easily tuned, the carrier diffusion distance is remote, the band edge position of the band structure is favorable for a wide range of electrocatalytic redox reactions, and the catalytic active site is maximally exposed. The Mn:CsPbBr3 exhibited preferable electrocatalytic hydrogen evolution (HER) performance in 1 mol/L KOH. The excess potential of the oxygen evolution reaction(OER) required to drive current densities of 10 and 100 mA cm‐2 is only 114.4 and 505.4 mV, with a Tafel slope of 43 mV dec‐1. At a current density of 10 mA cm‐2, the excess potential required for the HER is 158.6 mV and it exhibited excellent electrochemical stability. The Mn:CsPbBr3 nanocrystalline consists of two electrodes for the overall water splitting, requiring a voltage of only 1.45 V. Which in turn provides implications for the optimization of electrocatalysts in alkaline electrolytes with the aim of developing the next generation of 2D electrocatalysts for overall water splitting.