Preparation and Characterization of <scp>CS</scp>/<scp>GO</scp>/<scp>Bi₂Ce₂O₅S₂</scp>@Ag Composite Photocatalytic Membrane and Its Adsorption Catalytic Removal of Cr(<scp>VI</scp>)

ABSTRACT The separation and purification of wastewater containing Cr(VI) remains a challenging subject. The preparation of composite membranes capable of adsorbing and photocatalytically reducing Cr(VI) is a promising method for treating wastewater containing Cr(VI). In this study, a novel photocatalyst CS/GO/Bi 2 Ce 2 O 5 S 2 was prepared through the hydrothermal reaction of (NH 4 ) 2 Ce(NO 3 ) 6 with Bi(NO 3 ) 3 and (NH 2 ) 2 CS. Then the photocatalyst was dispersed in chitosan (CS)/graphene oxide (GO) solution to prepare the CS/GO/Bi 2 Ce 2 O 5 S 2 membrane, which was then immersed in AgNO 3 solution and in situ reduced to produce AgNPs, resulting in a novel photocatalytic membrane (CS/GO/Bi 2 Ce 2 O 5 S 2 /Ag). The results show that the membrane can reduce 99.75% of Cr(VI) in wastewater. The adsorption capacity of the photocatalytic membrane for Cr(VI) reached 235.34 mg/g, and the absorption processes conformed to the pseudo‐second‐order model and Langmuir model. This photocatalyst features a narrow band gap and a very high photogenerated carrier generation rate and photocatalytic efficiency. The electrochemical test shows that CS/GO/Bi 2 Ce 2 O 5 S 2 @Ag has the maximum photocurrent density and the minimum impedance, which can be more beneficial to the generation of photogenerated charge carriers. The results of this study realize the simultaneous adsorption, photocatalytic reduction, separation, and purification of wastewater containing Cr(VI), which has high efficiency, economic, and practical significance.