Construction of biomass carbon decorated TiO2 and g-C3N5 Z-scheme heterojunction photocatalyst for removal of rhodamine B

[Display omitted] •Design biomass carbon modified TiO2 and g-C3N5 Z-scheme heterojunction photocatalyst.•CTCN was eight and four times for Rh B degradation efficiency than g-C3N5 and TiO2.•The interaction of doping and heterojunction enhanced the photocatalytic activity.•Provide a green, economical and effective method for water resource treatment. Access to water resources is a serious problem worldwide, and limited access has brought numerous challenges to the human population. Therefore, establishing an effective method for removing pollutants is critical. Herein, a Z-scheme heterojunction photocatalyst, C-TiO2/g-C3N5 (CTCN), is synthesised via hydrothermal and calcination methods using walnut wood as biomass carbon source. The photocatalytic performances of the composite were assessed using rhodamine B (Rh B). The photocatalytic degradation efficiency of CTCN attained 96.6 % within 90 min. Furthermore, the degradation efficiency of Rh B was nearly eight and four times greater than that of g-C3N5 and TiO2, respectively. After five cyclic experiments, the degradation rate still reached 88 % for Rh B dye. These results prove that the synthesised composites have high photocatalytic stability. The outstanding photocatalytic performance of the CTCN composite may be attributed to the doping of biomass carbon and synergistic effect of the construction of the Z-scheme heterojunction at the two-material interface.