Photodegradation of 4-Nitrophenol by Visible-Light Driven Ternary Nanocomposite of N-TiO2 and Ag3PO4 Co-Grafted on Graphene Oxide: Influence of System Parameters and Kinetic Study

The photodegradation of 4-NP is extensively studied by ternary nanocomposite of N-TiO₂ and Ag₃PO₄ co-grafted on GO sheets. The photodegradation of 4-NP follows pseudo-first order kinetics, which can be fitted by Langmuir–Hinshelwood model. The kinetic study confirms that photodegradation is influenced by catalyst dose, initial 4-NP concentration and solution pH. The highest photocatalytic activity of 68% is achieved with N-TiO₂/Ag₃PO₄@GO(0.6) using a catalyst dose of 1.5 g L^–1 for initial 4-NP concentration of 10 mg L^–1 at pH 7.5 up to 150 min of visible-light illumination. The enhanced visible light absorption, substantial separation of photogenerated e^––h⁺ pair, improved surface area and faster interfacial charge separation between the three components in the ternary composite favoured the efficient photodegradation of 4-NP.