Visible light photocatalytic degradation of methylene blue by hydrated titanium dioxide nanoparticles incorporated within rice straw

A novel photocatalyst was successfully synthesized by immobilizing hydrated titanium dioxide (HTO) nanoparticle within rice straw (RS) via a sol–gel method. The HTO nanoparticles were successfully loaded onto the surface of RS confirmed by scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDS) and Brunauer–Emmett–Teller (BET) model. Through Fourier transform attenuated total reflection infrared spectroscopy (ATR-FTIR), the formed C–O–Ti bond in RS-HTO gave rise to a strong link and, hence, the charge transportation rate was improved. In the photocatalytic processes, the recombination of electrons and holes was smothered. In addition, thermogravimetric analysis (TGA) and differential thermogravimetric (DTG) proved RS-HTO had good thermal stability. The photocatalytic activity of RS-HTO nanocomposites was measured by the photo-degradation performance of methylene blue (MB) solution under visible light. The study showed that the photo-degradation rate of MB could reach 95.18%, which was higher than RS (approximately 20%). Meanwhile, based on experiment (ESR), MB was degraded by hydroxyl radicals (·OH). These results demonstrated that HTO nanoparticle within RS was an effective method for dyestuffs wastewater treatment.