Enhanced oxygen and hydrogen evolution activities of Pt/LaCoO3 perovskite oxide via in-situ exsolution of Pt nanoparticles

This report designed a Pt/LaCoO 3 composite electrocatalyst for electrochemical water splitting: LaCo 0.94 Pt 0.06 O 3 was prepared via the sol-gel method and then dealt with a heat treatment in 10% H 2 /Ar atmosphere at 350 °C. The XRD, HRTEM, SEM and XPS results show that the Pt nanoparticles (NPs) exsolve from the perovskite lattice and are homogeneously distributed on the surface. The HER and OER performance of the samples was tested in 1 mol·L -1 KOH solution and the findings illustrate that compared with LaCo 0.94 Pt 0.06 O 3 , Pt/LaCoO 3 owes better OER and HER performance. The improved performance could be up to the higher ratio of oxygen vacancies and improved charge transfer. Furthermore, the synergistic effect between Pt NPs and the LaCoO 3 matrix may also take a leading part in the future. Graphical abstract Figure SEM images of the samples: (a) LaCo 0.94 Pt 0.06 O 3 ; (b) Pt/LaCoO 3 . After the exsolution, the Pt/LaCoO 3 is well-developed with smooth surface and some nanoparticles are homogeneously distributed on the surface of the samples. The exsolved Pt nanoparticles can accelerate the electron exchange process between the matrix and its adsorbed intermediates, and ultimately promote the electrochemical reaction kinetics.