Recent advances in 3D g-C3N4 composite photocatalysts for photocatalytic water splitting, degradation of pollutants and CO2 reduction

Recently, g-C3N4 has exhibited excellent catalytic performances in photocatalytic water splitting for H2 and O2 generation, degradation of pollutants and CO2 reduction. However, the bulk g-C3N4 demonstrates some disadvantages such as low specific surface area, high defect density, fast recombination possibility of photogenerated electron-hole pairs, and non-recyclable characteristics, leading to low photocatalytic performance and efficiency. The three-dimensional (3D) network-like g-C3N4 composite materials constructed by nanotechnology can effectively improve the adsorption capacity, light response, structure stability and recyclability of photocatalysts, which results in a significant increase in the photocatalytic performance and utilization. It is a novel way to achieve high-efficient separation of photogenerated electron-hole pairs and improve photocatalytic activity. In this review, the recent research progresses especially the synthesis strategy of 3D g-C3N4 composite photocatalysts and their applications for photocatalytic water splitting, degradation of organic pollutants and CO2 reduction are firstly and systematically introduced and discussed. The review and prospect of 3D g-C3N4 composite materials can provide some new ideas and directions for the research and development of 3D g-C3N4 composite photocatalysts with high activity, strong adsorption, facile recyclability, and no secondary pollution.