The two dimension carbon quantum dots modified porous g-C 3 N 4 /TiO 2 nano-heterojunctions for visible light hydrogen production enhancement

Abstract The dual function carbon quantum dots (C QDs) modified porous g-C 3 N 4 /TiO 2 two dimension (2D) nano-heterojunctions are prepared by a simple route, through which the porous g-C 3 N 4 nanosheets are prepared by thermal polycondensation, the TiO 2 nanoparticles are introduced by hydrothermal method and the C QDs are introduced on the surface of the porous g-C 3 N 4 and TiO 2 by coupling successively. The results indicate that TiO 2 and C QDs are well combined with the porous g-C 3 N 4 . The hydrogen production properties of those 2D nano-heterojunctions are investigated, which exhibit an obvious hydrogen production enhancement (nearly two orders of magnitude) compared with those of the unmodified samples. Through analysis, this enhancement of the photocatalystic hydrogen production is attributed to the dual function C QDs with high catalytic activity of H 2 O 2 decomposition and unique up-conversion photoluminescence.