Preparation, Characterization and Photocatalytic Activity of Sodium Humate/Nano-TiO2 Coating on Glass Spheres for Flue Gas Denitrification

Abstract

A new photocatalyst of sodium humate (HA–Na)/Nano-TiO2 coating on the glass spheres for flue gas denitrification (DeNOx) was prepared using the impregnation method. The HA–Na/TiO2 is characterized by Brunauer–Emmett–Teller (BET), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and scanning electron microscope (SEM). The photocatalytic activity of HA–Na/TiO2 on removing NOx was investigated in a self-designed photocatalytic reactor. The synergistic mechanism of HA–Na and TiO2 on DeNOx is also proposed and demonstrated. The experimental results indicate that specific surface area and average pore size of HA–Na are improved owing to the mixed TiO2 nanoparticles. The crystal structure of TiO2 has little change after mixing with HA–Na. Due to high photocatalytic performance of TiO2, NO was oxidized to NO2 and HNO3 eventually. On the other hand, HA–Na support can absorb and react with HNO3, which accelerates 10% of the catalytic reaction of TiO2 and the utilization of light source. The chemical and physiological activity of oxidized HA–Na are improved than the original humate. The HA–Na/TiO2 photocatalysts show great property on eliminating NOx because of the promoting effect between HA–Na and TiO2, and the NO removal efficiency can reach to 80% at the optimum condition.