Mechanochemical Synthesis and Characterization of N-doped TiO2 for Photocatalytic Degradation of Caffeine

The present study reports the synthesis of N-doped TiO2 photocatalyst for the degradation of caffeine using mechanochemical grinding method from the mixture of titania/urea followed by calcination at 400 ⁰C. The phase composition, particle size, surface area, morphology and optical properties were characterized. The XRD results revealed that anatase is dominant and the size of crystal is decreased from 35.8 to 33 nm after mechanical doping. An improved surface area of 42.9 m2g-1 is also reported. The morphology from SEM also showed a uniform yellow-like powder indicating complete dispersion of nitrogen on the TiO2 surface. The prepared sample showed visible-light absorption in the region 430 nm corresponding to band gap energy 2.88 eV, indicating its potential applications as a visible light induced photocatalyst. Photocatalytic oxidation of caffeine were investigated in 300 minutes irradiation time and N-doped TiO2 demonstrated the higher removal efficiency of 97% compared to commercial TiO2 powder with 91% efficiency at the same experimental condition.