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

A new photocatalyst of sodium humate (HA-Na)/Nano-TiO2 coating on the glass spheres for flue gas denitrification (DeNO(x)) 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 DeNO(x) 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.