Significantly Enhanced Photocatalytic Hydrogen Generation over a 2D/2D Z-Scheme La₂NiO₄/g-C₃N₄Hybrid Free of Noble Metal Cocatalyst

A 2D/2D Z-scheme La2NiO4/g-C3N4 heterojunction was favorably created with a 2D La2NiO4 perovskite and g-C3N4 nanosheet through a calcination route. Notably, the photocatalytic activities of all La2NiO4/g-C3N4 hybrids can be found to have effectively increased over that of pure La2NiO4 or g-C3N4 especially when a noble metal was not used as a cocatalyst. Particularly, when the mass fraction of La2NiO4 was 3 wt %, the photocatalytic hydrogen generation rate of the La2NiO4/g-C3N4 composite was the highest, which was 53.8 and 43.9 times that of bare La2NiO4 and g-C3N4, respectively. The Z-scheme heterojunction was found to effectively improve the catalytic ability by enhancing the photoinduced charge carrier migration efficiency, as well as both the oxidation and reduction capabilities. Our work should be of value for designing highly efficient and visible light-responsive heterojunction photocatalysts free of the noble metal cocatalysts.