Composite aerogel membranes with well dispersed nano M-TiO₂@GO for efficient photocatalysis

Photocatalytic technology plays a crucial role in addressing energy shortages and environmental pollution. TiO₂ has been widely applied in photocatalysis but encounters several issues, such as the easy recombination of photoexcited electrons and holes, the poor dispersion uniformity, the wide band gap, and the complex recovery process. In this work, a recyclable M-TiO₂@GO/modified chitosan composite aerogel membrane was designed and prepared for photocatalytic application, with TiO₂ nanoparticles generated by MXene oxidation (M-TiO₂) serving as the photocatalyst and modified chitosan acting as the matrix. The experimental results demonstrated that M-TiO₂ nanoparticles were in situ generated on the surface of graphene oxide (GO) nanosheets, forming M-TiO₂@GO nanoparticles with a 0D@2D structure. Due to the combined effects of M-TiO₂ and carbon (another product resulting from the oxidation of MXene), the band gap of M-TiO₂ nanoparticles was decreased from 3.10 eV to 2.06 eV, which significantly enhanced the photocatalytic efficiency of TiO₂. When the photocatalytic degradation performance of the aerogel membrane containing M-TiO₂@GO nanoparticles was evaluated, the sample C₁₅M₁₅G₅ (containing modified chitosan 15 mg/M-TiO₂ 15 mg/GO 5 mg) demonstrated nearly complete degradation of Rhodamine B and Acid Blue 1 within 120 min, exhibiting excellent photocatalytic performance. In addition, the antibacterial properties of C₁₅M₁₅G₅ were examined and found that the antibacterial rate reached 100% following ultraviolet irradiation. In summary, this study presents an innovative strategy to obtain well-dispersed nano TiO₂, which can be used to prepare composite photocatalytic aerogel membranes with excellent catalytic performance and complete recyclability.