Multistimuli Activation of TiO2/α-Alumina Membranes for Degradation of Methylene Blue

TiO2/α-Al2O3 porous membranes were prepared and tested under different stimuli, including UV and simulated solar irradiation, with or without the addition of hydrogen peroxide (H2O2), and by using Methylene Blue (MB) as a model organic pollutant to probe the oxidative catalytic activity of the membranes. An ultrathin TiO2 layer was coated on porous α-Al2O3 substrates by combining a sol–gel process with a spin coating technique. Uniform TiO2-coated alumina surfaces were obtained, which resulted in an increased pollutant adsorption on the semiconductor surface, a crucial requirement for achieving enhanced catalytic performances. The photocatalytic activity of these functionalized membranes was tested in a photocatalytic membrane reactor (PMR), by monitoring the photodegradation of MB in water. Under UV irradiation, 80% of MB degradation was achieved in 4 h. Concomitantly, the residual pollutant is completely retained by the membrane in the feed solution, and a pollutant-free permeate can be recovered. Notew...