Fast Removal of Methylene Blue via Adsorption-Photodegradation on TiO2/SBA-15 Synthesized by Slow Calcination

Abstract

TiO2/SBA-15 photocatalysts were successfully prepared by impregnating low loading titania to SBA-15 via slow calcination. The photocatalyst is efficient for fast methylene blue removal via adsorption and photodegradation methods. The impregnation of low TiO2 loading via slow calcination enhanced TiO2 dispersion that preserved the SBA-15 porosity and uniform morphology. High interfacial interaction of TiO2/SBA-15 improves TiO2 photoresponse by narrowing the bandgap, resulting in a stronger redox ability. The methylene blue removal on 10%TiO2/SBA-15 followed the pseudo-second-order kinetic model that reached 67% removal efficiency in 90 min. The synergy between adsorption and photodegradation is responsible for the fast methylene blue removal. These results indicate the importance of maintaining the adsorption capacity in SBA-15 after impregnation with TiO2 for efficient adsorption-photodegradation processes, which can be achieved by controlling the deposition of TiO2 on SBA-15. A low titania loading further reduced the cost of photocatalysts, thus becoming a potential material for environmental pollution treatment.