Noble-metal-free Ni3C as co-catalyst on LaNiO3 with enhanced photocatalytic activity

In this study, Ni3C nanoparticles (NPs) were loaded on LaNiO3 NPs as a co-catalyst during the photocatalytic H2 evolution. The evolution rate of the LaNiO3-3 wt%Ni3C composite (4093.9 μmol g−1 h−1) is about 5 times and 2 times as that of pristine LaNiO3 NPs (819.2 μmol g−1 h−1), and 1 wt% Pt loaded LaNiO3 NPs (1927 μmol g−1 h−1). The effects of co-catalyze with Ni3C on light absorption, electron-hole spatial separation, and surface H2-evolution kinetics are investigated. Loading with Ni3C can enhance the spatial separation of electron-hole pairs, and improve the H2-evolution kinetics. Further investigation shows that surface decomposition of LaNiO3 NPs can only be observed when the Ni3C content is over 3 wt%, caused by the reductive carbon source needed in the loading process. This work indicates that transition metal carbide can be a promising co-catalyst candidate for oxides in photocatalytic applications without concerning corrosion from the reductive carbonaceous precursors in the loading process.