Objective BiVO4-CdS composite photocatalysts with the wood biomimetic micro-nanopore structure were prepared from wood processing residues. The wood template was used to form more heterojunction structures, improve the catalytic performance of the photocatalytic material and expand the application of BiVO4 in the treatment of wood dye wastewater.
Method BiVO4-CdS composite photocatalysts were prepared by impregnation-calcination and chemical deposition using wood processing residues from three species of wood (fir, poplar, and balsa).
Result All three BiVO4-CdS composite photocatalysts with wood biomimetic structures exhibited good adsorption-photocatalytic degradation of RhB. The lower-density balsa-wood BiVO4-CdS showed a high removal rate of RhB (29.26%) after reaching adsorption equilibrium; the degradation rate of RhB under visible light was 96.01% in 120 min, and its reaction rate was 6.69 and 3.37 times higher than that of BiVO4 and BiVO4-CdS without a template. After ten adsorption-photocatalytic degradation cycles, the balsa-wood BiVO4-CdS still achieved a degradation efficiency of over 85%.
Conclusion The biomimetic structure of wood gives the composite photocatalyst a rich pore structure. The cavity wall structure in the low-density wood facilitates the catalyst to obtain a large specific surface area and stable pore structure after impregnation and calcination treatment. At the same time, it also promotes the formation of the BiVO4-CdS heterojunction structure, which accelerates the rapid adsorption and degradation of pollutant molecules during the photocatalytic reaction.