Novel Calcium Carbonate-titania nanocomposites for enhanced sun light photo catalytic desulfurization process

Preparation of active photocatalytic nanostructures to harvest the abundant sunlight energy is a recent worldwide direction for clean energy production and environmental management. Following this target, different calcium carbonate-titania nanostructures were prepared by three different pathways using available raw materials such as limestone as calcium precursor. After characterization of the prepared materials with X-ray diffraction (XRD), X-ray fluorescence (XRF) patterns, Fourier transmission infrared (FT-IR), high resolution transmission electron microscope (TEM), N₂ adsorption-desorption isotherm, UV-vis diffuse reflectance and photoluminance (PL), the materials were applied as novel photocatalysts for desulfurization of dibenzothiophene (DBT) and gas oil using different radiation sources at room temperature. It has been obtained that, 95% desulfurization of DBT was possible under 1 h visible light irradiation with linear halogen lamp (LHL) at catalyst/DBT-solution = 10 g/L, while ultra-clean diesel production (99% removal, 3.47 ppm) could be obtained via normal sunlight photochemical desulfurization of diesel fuel by calcium carbonate titania photocatalyst in presence of H₂O₂ and acetic acid as oxidizing agents and acetonitrile as a solvent. Here, the followed preparation pathway produced highly active calcium titanate photocatalysts with tunable band gap energy (2.05 eV), reduced electrons/hole pairs recombination and stable photocatalytic activity with enhanced visible light removal of organosulfur compounds for economic ultra-clean fuel production, pollution control, and environmental management.