In order to acquire an efficient photo-catalyst for generating hydrogen directly on the material, herein, we introduce the well-known catalyst, LaCoO3, to the community of water splitting using solar energy. By combining with Au nanoparticles, we find that hot electrons injected from Au nanoparticles to LaCoO3 are responsible for amplifying the photo-catalytic efficiency and the well-known thermal-stimulus for driving chemical transformations is not observed to be influential. Such charging process to the catalysts is crucial for promoting the subsequent catalytic reactions. Thus, this paper provides insights into the working mechanism of plasmonic based photo-catalyst. (C) 2017 Elsevier B.V. All rights reserved.