Fabrication of porous graphitic carbon nitride-titanium dioxide heterojunctions with enhanced photo-energy conversion activity

Porous graphite-phase polymeric carbon nitride（GPPCN）/TiO2 donor-acceptor heterojunction was facilely fabricated through the combination of a template technique with a co-calcination process,which exhibited much higher photoelectric activity compared to pristine carbon nitride and TiO2.The precursor of porous GPPCN（pGPPCN）,porous melem,was prepared by using a green template,calcium carbonate,which could be easily removed by diluted hydrochloride.The pGPPCN/TiO2 heterojunction was then obtained by the assembly and subsequent co-calcination of TiO2 nanoparticles with porous melem.The formation of pGPPCN/TiO2 donor-acceptor heterojunction prepared by this method showed improved surface area and light absorption.Moreover,the composite presented much higher photo-energy conversion activity than those of GPPCN,pGPPCN and TiO2,which could be mainly ascribed to the high charge carrier separation efficiency.This study provides a new approach for the design and development of various photocatalysts with high efficiency for applications in energy fields.