Hollow core-shell Z-scheme heterojunction on self-floating carbon fiber cloth with robust photocatalytic-photothermal performance

The combination of photothermal catalysis and photocatalysis is an effective method to remove Cr(VI) and degrade organic pollutants using solar energy. Herein, hollow flower-like W18O49@ZnIn2S4 core-shell Z-type heterojunctions were prepared on carbon fiber cloth (CC) by two methods, hydrothermal method and solvent heat, which are easy to operate. The prepared photocatalysts showed very excellent photocatalytic degradation for the redox removal of Cr(VI) and degeneration of bisphenol A (BPA) under simulated sunlight, and the W18O49@Znln2S4/CC composites showed 95% and 100% removal of bisphenol A (BPA) and Cr(VI), respectively. The formation of Z-type heterojunctions promoted rapid carrier transfer, and the hollow structure improved light utilization, while the core-shell structure increased the interfacial area and number of active sites. In addition, the oxygen vacancies in W18O49 have ligated unsaturated sites and unpaired electrons, which can lower the reaction energy barrier and promote molecular activation. The effects of different catalyst types, different pH values, and different initial concentrations of BPA on the photocatalytic performance were demonstrated. Furthermore, the W18O49@Znln2S4/CC composite exhibited excellent stability and reusability in 10 consecutive cycles of experiments. Its easy recovery and high stability imply potential practical applications, providing an effective strategy for the development of a new efficient catalyst for the treatment of wastewater and a sustainable environment.