TiO2 Photocatalytic Ultrafiltration Membrane Developed with Suspension Plasma Spray Process

The suspension plasma spray process was used to fabricate photocatalytic ultrafiltration membranes for potential water and wastewater treatment applications. An aqueous suspension of 30 wt.% titanium dioxide with an average individual particle size of around 30 nm was used as feedstock material. The spray parameters, such as suspension solid content, suspension feed rate, and spray distance, were optimized using an Ar/H2 plasma to retain a fraction of unmelted feedstock nanoparticles as the source of fine pores in the membrane microstructure. The microstructure, porosity, phase composition, and pure water permeability of the membranes were characterized comprehensively. The average pore size of the membrane was around 40 nm, which was very close to the particle size of the pristine titanium dioxide powder. The membranes demonstrated a high water permeability between 2000 and 7200 L m−2 h−1 bar−1, which was inversely proportional to the thickness. They also exhibited significant photocatalytic activity under visible light.