Photocatalytic degradation of dye pollutant over Ti and Co doped SBA-15: Comparison of activities under visible light

Thick-walled hexagonally ordered Cobalt and titanium loaded SBA-15 mesoporous photocatalysts were prepared by impregnating the metal precursor solution on the hydrothermally stable support. The catalysts were analyzed using various spectroscopic and diffraction techniques. XRD measurements revealed that Co exists as its spinel structure Co3O4 and Ti is present in the anatase TiO2 phase. FTIR showed the absorption bands of Co3O4 around 667 and 565 cm−1. The visible light absorbance of the photocatalytic systems was studied by Diffuse Reflectance Ultraviolet–Visible spectroscopy (UV–vis DRS) measurements. Systems exhibited fairly good performance as photocatalysts for pollutant degradation under visible light. SBA-15 support was helpful in the easy separation of catalysts after the completion of the degradation. In the case of cobalt loaded SBA-15, activity is found to be maximum when the cobalt loading is 40% whereas 50% Ti loaded SBA-15 is found to be the most active among the prepared systems for the degradation of the dye pollutant methylene blue (MB).

► Methylene blue is effectively degraded over Co and Ti doped SBA-15. ► Visible light is harvested successfully for dye pollutant degradation making the process economical and ecological. ► Support SBA-15 makes the photocatalysts easily separable from the cleaned solution.