Robust and recyclable macroscopic g-C3N4/cellulose hybrid photocatalysts with enhanced visible light photocatalytic activity

Robust, metal-free, macroscopic 3D porous g-C3N4/cellulose (CN/CE) hybrid photocatalyst was successfully fabricated by the co-assembly of g-C3N4 and cellulose substrate. The morphology, structure, mechanical property, optical and electrochemical performances, and photocatalytic activity of the CN/CE were investigated in detail. The obtained CN/CE hybrid photocatalyst possessed homogeneous 3D interconnected network structure, excellent mechanical strength and considerable recyclability. Also, the CN/CE hybrid photocatalyst exhibited both an excellent adsorption capacity and improved photocatalytic activity toward methylene blue (MB) degradation with degradation rate of 99.8%, much higher than that of pure g-C3N4 (54.2%). The enhanced photocatalytic performance of CN/CE derived from the synergistic effects of homogeneous 3D interconnected network structure and syncretic interfaces between g-C3N4 and cellulose, facilitating mass transport, light absorption and reactant adsorption, as well as the transfer of the photogenerated electrons. Moreover, the CN/CE hybrid photocatalyst indicated a high reusability and stability without significant reduction in its efficiency with nearly 96% of MB degradation after four cycles. This work not only demonstrated the importance of homogeneous interconnected network structure to prepare highly effective photocatalyst, but also provided a new insight into the approach for design and utilization of stable and recyclable metal-free photocatalyst for visible light derived contaminant degradation.