High-Strength and Ultrathin Photocatalytic Membranes with High-Loading Catalysts for Water Treatment

This paper presents a highly efficient method for preparing ultrathin, high-strength photocatalytic membranes with a three-layer structure and high-loading catalysts on both sides. The photocatalytic membranes were prepared by simultaneous biaxial stretching using ultrahigh-molecular-weight polyethylene as the matrix, TiO2 nanoparticles as the catalyst (80 wt %), and liquid paraffin as the plasticizer. The mechanical properties of these membranes were tested, and the tensile strength of the membrane with a biaxial stretching ratio of 7 × 7 reached 62 MPa. Three types of dyes, methyl orange, methylene blue, and Congo red, and their mixed solutions were selected as model pollutants to investigate the photocatalytic properties of the prepared photocatalytic membranes. Results show that the 7 × 7 membrane can almost degrade the above pollutants within 100 min. Moreover, this membrane exhibits remarkable stability in cyclic photodegradation tests, with a degradation rate reaching 95.9% after five cycles. This preparation method is anticipated to provide a good carrier for various photocatalysts, making the photocatalytic membrane suitable for a wide range of applications in the treatment of water contamination.