Tape casting and phase inversion derived easily recyclable PVDF@g-C3N4/Bi2W0.98Nb0.02O6 porous film for high performance and long-term photocatalytic pollutants degradation

Recovery of photocatalysts is very challenging for practical applications, such as the degradation of pollutants, especially when the reaction occurs in aqueous solution. To address this issue, herein, a novel and easily recyclable visible-light-driven photocatalytic porous PVDF@g-C3N4/Bi2W0.98Nb0.02O6 composite film is proposed. In this composite material, the polyvinylidene fluoride (PVDF) film acts as a loading matrix, the direct two-dimensional/two-dimensional (2D/2D) Z-scheme heterojunction between g-C3N4 (CN) and Bi2W0.98Nb0.02O6 (BW2) nanosheets serve as photocatalytic units while the porous structure provides a high surface area and thus, an increasing number of photocatalytically active sites. The physical properties of CN, BW2, and CN/BW2, as well as the photocatalytic performance of the composite film are systematically discussed. The CN/BW2 heterojunction exhibited superior ability to generate and transport photo-induced carriers than that of the pristine CN and BW2 samples. Hence, the almost complete degradation of RhB was realized in 150 min of reaction (apparent degradation rate, k(app) = 0.02006 min(-1)). In addition, the PVDF@CN/BW2 film, which was easily recovered from the aqueous solution, maintained the photocatalytic activity for six consecutive catalytic runs. The successful achievement of this work can be used as the starting point for the development of new highly efficient and recyclable photocatalysts.