PROPERTIES OF APATITE WITH NITROGEN-DOPED TITANIUM DIOXIDE APPLIED TO REMOVE SOME ORGANIC COMPOUNDS FROM INDOOR AIR

Abstract

The purpose of this study is to present some properties of apatite-coated nitrogen-doped TiO₂ (Ap/N-TiO₂) with good photocatalytic activity in the visible light region and apply it to remove formaldehyde gas in indoor air.

The morphology, elemental composition ratio as well as the surface area and average pore size of the materials were confirmed by SEM, EDX and BET, respectively. N is dopped in the crystal of TiO₂ at a different molar ratios, the results showed that with a ratio of 2/1 (N/TiO₂), the mass percent of N that was injected into the TiO₂ crystal is the highest and the doping is the best compared to the remaining samples. In the visible light region (365 nm, 20 W), the N-doped Ap/TiO₂ sample has better photocatalytic activity than the undoped sample. Methylene blue solution with an initial concentration of 20 ppm was completely reduced after 120 minutes of illumination, while Formaldehyde at a concentration of 8 ppm, the treatment efficiency was only 78% after 26 hours. After treatment, the concentration of Formaldehyde reached the permissible standard QCVN 06:2009/BTNMT. Ap/N-TiO₂ materials will have great promise in reducing pollution by other harmful chemicals in the air environment.