Role of Ag and g-C3N4 over CaTiO3 for effective photocatalytic degradation of nitrobenzene

Abstract

In the present study, g-C3N4/CaTiO3 (GCT) heterostructure with various Ag contents have been synthesized via simple hydrothermal method and characterized using various instrumental techniques. Stability of synthesized samples was measured by thermogravimetric analysis (TGA) and zeta potential measurement. The photocatalytic activity of all the synthesized was evaluated by the degradation of nitrobenzene (NB) in aqueous media. The photocatalytic activity of heterostructure AGCT was observed enhanced under the light irradiation. This would be attributed to the suitable band structure, resulting in the efficient charge separation and transfer of photogenerated charge carriers. The final percentage of degradation was observed 70% with AGCT5 and 64% with AGCT1 which were highest among other catalysts applied after 2 h. The Ag doping in CT catalyst led to antagonist performance, and to better degradation of NB. The multivalency of Ag leads to prevent agglomeration and recombination of electrons and holes and transferring them from Ag to Ca. The reaction rate (2.36 × 10−3 molL−1 min−1 at 20 °C) and percentage degradation (∼70%) were observed to get increased with the increase in the temperature with the apparent activation energy of 40.3 kJ/mol. The enhanced performance at increased temperature was attributed to overcome the energy of activation and high mobility of charge carriers.