Solvothermal fabrication of activated semi-coke supported TiO2-rGO nanocomposite photocatalysts and application for NO removal under visible light

Abstract

The photocatalysts of activated semi-coke supported TiO2-rGO nanocomposite (TiO2-rGO/ASC) with different contents of reduced graphene oxide were fabricated by one-step solvothermal method for NO removal under visible light irradiation. It was confirmed that 8% content of reduced graphene oxide presented the best NO photooxidation performance under visible light irradiation at 70°C with 350–400mg/m3 NO,5% O2 and 5% relative humidity. The reasons for improved activity were discussed, alloyed with the mechanism of producing CO. Detailed structural information of TiO2-rGO/ASC photocatalysts was characterized by scanning electron microscope (SEM), energy dispersive X-ray Spectroscopy (EDX), X-ray diffraction analysis (XRD), UV–Vis diffuse reflectance spectra (UV–Vis DRS) and photoluminescence (PL), which indicated that the introduction of rGO was responsible for well dispersion, smaller crystalline size, red shift of absorption band and suppressing quick photo-induced charges recombination of TiO2-rGO/ASC photocatalysts. Optimization of operational parameters with 70°C, 8% O2 and 8% relative humidity were also obtained. Deactivation of TiO2-rGO/ASC photocatalysts for NO removal was investigated by Fourier-transform infrared (FTIR) analysis. Regeneration experiments showed that thermal vapor regeneration would be optimal method owing to excellent regenerative capacity and inexpensive procedure.