Construction of direct Z‐scheme g‐C₃N₄/TiO₂ nanorod composites for promoting photocatalytic activity

Abstract

Direct Z‐scheme g‐C 3 N 4 /TiO 2 nanorod composites were prepared for enhancing photocatalytic activity for pollutant removal. The characterization revealed that the g‐C 3 N 4 /TiO 2 nanorod composite formed a close interface contact between g‐C 3 N 4 and TiO 2 nanorods, which was of benefit for the charge transfer and resulted in its high photocatalytic activity. The g‐C 3 N 4 /TiO 2 nanorod composites exhibited higher photocatalytic activity for degradation of Rhodamine B (RHB) than bare g‐C 3 N 4 and TiO 2 nanorods. The high photocatalytic activity of g‐C 3 N 4 /TiO 2 nanorod composites is attributed to the formation of the direct Z‐scheme system, in which the electrons from the conduction band (CB) of TiO 2 combine with the holes from the valence band (VB) of C 3 N 4 while the electrons from the CB of C 3 N 4 and holes from the VB of TiO 2 with stronger redox ability are used to reduce and oxidize pollutants. Based on the radical‐trapping experiments, the main reactive species for RHB degradation are O 2 − and · OH, which are produced by photoinduced electrons and holes with high redox ability. This work provides insights into the photocatalytic mechanism of composite materials for the photocatalytic removal of organic pollutants.