Phytochemical-assisted synthesis of TiO(2)/graphene oxide nanocomposite using Syzygium cumini for enhanced photocatalytic degradation of organic pollutants in aqueous systems.

内容摘要

Photodegradation is gaining attention as an effective approach for treating wastewater, especially for removing organic pollutants. In this work, we present an environmentally friendly green route to synthesize titanium dioxide (TiO₂) nanoparticles using Syzygium cumini leaf extract as a reducing and capping agent. Graphene oxide (GO) was prepared using Hummers' method, and the TiO₂/GO nanocomposite was subsequently formed via a hydrothermal process. This green synthesis route offers a sustainable, non-toxic, and low-cost alternative to conventional methods. The materials were thoroughly characterized using XRD and FTIR to confirm their composition, SEM and TEM for morphological analysis, and UV-DRS to study their optical properties. The photocatalytic performance was evaluated through the degradation of methylene blue (MB) in water. The TiO₂/GO nanocomposites achieved an impressive 99.2 % degradation of methylene blue (MB) after 240 min. Good stability was maintained over three reuse cycles, with a degradation efficiency of 70.7 % and a rate constant of 0.01167 h⁻¹, following a first-order kinetic model. The computational investigation of the molecular orbitals of MB also helps to elucidate its photoinduced reactivity, offering valuable insights into the underlying pathways of the photocatalytic process. These results highlight the potential of green-synthesized TiO2/GO nanocomposites as efficient and reusable photocatalysts for water purification.