The immobilization of photocatalysts is considered an effective approach to solve the problem of the difficult recycling of powdered nanocatalysts after photocatalytic degradation. In this paper, tin dioxide/titanium dioxide (SnO₂/TiO₂) composite nanoparticles with excellent photodegradation performance and poly(vinylidene fluoride) (PVDF) resin were used as raw materials to prepare composite membranes for the catalytic degradation of rhodamine B (RhB) dye via a non-solvent-induced phase separation method. Specifically, the basic properties of SnO₂/TiO₂ composite nanoparticles were systematically analyzed, the photocatalytic performance of SnO₂/TiO₂/PVDF composite membranes was thoroughly investigated, and the photocatalytic mechanism has been revealed. Experimental results showed that the SnO₂/TiO₂ composite photocatalyst demonstrates a higher photocatalytic activity than the single photocatalyst with the SnO₂/TiO₂ composite comprising Sn/Ti in a molar ratio of 1 : 6, showing the highest photocatalytic performance. After SnO₂/TiO₂ composite particles were used as a kind of raw material for the production of PVDF membrane, the photocatalytic degradation rate of RhB by the SnO₂/TiO₂/PVDF composite membrane was as high as 91.84%. Moreover, ˙OH and h⁺ play a very important role in the whole photocatalytic degradation process. In summary, this paper will provide an effective guidance to improve the photocatalytic degradation of SnO₂/TiO₂/PVDF composite membranes, which will ultimately provide a broad potential application of photocatalysis in the field of water treatment.

At present, the types of pollutants in wastewater are more and more complicated, however, the multifunctional membrane materials are in short supply. To prepare a membrane with both high efficient oil-in-water emulsion separation performance and photocatalytic degradation performance of organic dyes, the bifunctional separation membrane was successfully prepared by electrostatic spinning technology of PVDF/PEMA and in situ deposition of anatase TiO₂ nanoparticles containing Ti³⁺ and oxygen vacancies (O_v). The prepared composite membrane has excellent hydrophilic properties (WCA = 15.65), underwater oleophobic properties (UOCA = 156.69), and photocatalytic performance. These composite membranes have high separation efficiency and outstanding anti-fouling performance, the oil removal efficiency reaches 98.95%, and the flux recovery rate (FRR) reaches 99.19% for soybean oil-in-water emulsion. In addition, the composite membrane has outstanding photocatalytic degradation performance, with 97% and 90.2% degradation of RhB and AG-25 under UV conditions, respectively. Several oil-in-water separation and dye degradation experiments show that the PVDF composite membrane has excellent reuse performance. Based on these results, this study opens new avenues for the preparation of multifunctional reusable membranes for the water treatment field.