Fabricating Bi2WO6/lignin-derived interconnected porous carbon composite for efficient dye removal

Application of Bi 2 WO 6 (BWO) as a photocatalyst for organic wastewater treatment is limited by low removal efficiency. Porous carbon is often used to coupling with BWO for improving its removal efficiency. In our study, we found that the porous structure of carbonaceous substrates is very important for their modification properties. We examined the effect of carbonaceous substrates with different pore structures as a carrier on dye removal performance. The results showed that the interconnected porous structure was more effective for coupling with BWO than hierarchical porous, micro–mesoporous, and microporous structures. This structure facilitated uniform BWO loading owing to low mass transfer and was not prone to blockage after loading. The obtained BWO/lignin-derived interconnected porous carbon (BWO/LIPC) composite presented efficient contaminant removal via synergistic adsorption and photocatalysis. After 3 h of light exposure, BWO/LIPC-5 % exhibited a 96.5 % removal efficiency for Rhodamine B (initial concentration of 40 mg·L −1 ), with a removal rate 6.3 times that of pure BWO. After five use cycles, the removal efficiency remained above 90 %. The introduction of LIPC increased BWO adsorption performance. Dye molecules were concentrated on the BWO/LIPC surface, thus optimizing photocatalytic efficiency. Moreover, photoelectrochemical characterization revealed that LIPC served as an electron acceptor, effectively inhibiting the recombination of photogenerated electron–hole pairs in BWO and enhancing its photocatalytic activity. This dye removal strategy involving synergistic adsorption and photocatalysis provides valuable insights for developing efficient materials in wastewater remediation.