Three dimensional hierarchical heterostructures of g-C 3 N 4 nanosheets/TiO 2 nanofibers: Controllable growth via gas-solid reaction and enhanced photocatalytic activity under visible light.

Graphitic C3 N4 nanosheets were uniformly grown on electrospun TiO2 nanofibers with three-dimensional nanofibrous networks via a facial gas-solid reaction. The mass loading of g-C3 N4 nanosheets could be easily controlled by adjusting the mass ratios of gaseous precursors (urea) to TiO2 NFs. The three-dimensional hierarchical heterostructures of g-C3 N4 nanosheets/TiO2 nanofibers could be obtained with excellent distribution and high specific surface area of 121.5m2 g-1 , when the mass loading of g-C3 N4 was 59.8wt.%. Under visible light irradiation, the degradation rate constant (rhodamine B) and the H2 evolution rate of the heterostructures were about 4.6 and 1.6 times of pure g-C3 N4 , while 23 and 167.8 times of TiO2 nanofibers, respectively. Their enhanced performance could be attributed to the effective charge separation and electron transfer process. Our work provides an attractive strategy to construct various three-dimensional hierarchical heterostructures of g-C3 N4 nanosheets for environmental and energy applications.