Photocatalytic performance of BiVO₄-CdS based on wood templates

  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.