Ti3C2/W18O49 hybrid membrane with visible-light-driven photocatalytic ability for selective dye separation

Abstract

Toxic organic dyes are a serious threat to the global environment, and membranes with catalytic properties show great promise as a green water treatment method for removing these pollutants. Herein, Ti3C2/W18O49 photocatalytic membranes were constructed by vacuum filtrating Ti3C2 and W18O49 to form a hybrid layer on a mixed cellulose ester (MCE) support. The efficient separation of dyes was attributed to the negative charge and abundant –OH groups of Ti3C2/W18O49, which can capture cationic dyes by electrostatic adsorption and form hydrogen bonds with the amino groups of dye molecules. Moreover, the Ti3C2/W18O49 membrane exhibited excellent photocatalytic performance and a dye-contaminated membrane was regenerated under visible light in 120 min. The two component materials complement each other, with the W18O49 providing adsorption sites and photocatalytic ability and the Ti3C2 serving as an electron trap and improving charge separation. Photoinduced electrons in the conduction band of W18O49 are transferred to Ti3C2 to form O2–, while holes remain in the valence band of W18O49 to generate OH, and h+. O2– and OH are mainly responsible for the degradation of dyes. Therefore, this efficient and easily prepared membrane shows practical potential as a next-generation method for dye removal from water.