Anchoring of copper sulfide on cellulose fibers with polydopamine for efficient and recyclable photocatalytic degradation of organic dyes

Due to its narrow band gap, Copper sulfide (CuS) exhibits great potential in photocatalytic degradation of organic dyes. However, there are still some drawbacks in the CuS photocatalytic system, such as easy aggregation, poor reusability, high recombination rate of photogenerated electron-hole pair, and photocorrosion damage. In this study, CuS was anchored onto cellulose fibers (CF) with the help of polydopamine (PDA) for constructing composite paper (CF/PDA/CuS paper) with high photocatalytic efficiency and good reusability. After PDA coatings formed on cellulose fibers, the chelation of Cu2+ by the catechol group of PDA provided uniform and stable growth sites for CuS, resulting in CuS anchoring in the PDA matrix for increasing the loading capacity and stability of CuS on cellulose fibers. In addition, PDA improved the separation efficiency of photogenerated electrons in CuS and inhibited the photocorrosion of CuS. The CF/PDA/CuS paper exhibited prominently enhanced photocatalytic activity and photocatalytic stability for the degradation of Rhodamine B under near infrared light irradiation. The photocatalytic activity of CF/PDA/CuS paper was about 5.8 times higher than that of CF/CuS paper. During 10 cycles, the photocatalytic efficiency of CF/PDA/CuS paper for degrading Rhodamine B was always above 92 % and the PDA/CuS hybrid structure was always stable on cellulose fibers. This work inspires the construction of stable PDA/CuS hybrid structure on cellulose fibers for a composite paper with high photocatalytic efficiency and good reusability. •A novel CuS-based photocatalytic composite paper was prepared.•The PDA coatings formed on the cellulose fibers were used to anchor CuS.•The chelation of Cu2+ by the catechol group of PDA provided growth sites for CuS.•PDA separated the photogenerated electrons and inhibited the photocorrosion of CuS.•The composite paper exhibited high photocatalytic activity and good reusability.