Fabrication of N-Doped Graphene@TiO₂ Nanocomposites for Its Adsorption and Absorbing Performance with Facile Recycling

The present work aims to synthesize nitrogen-doped reduced graphene oxide-titanium dioxide nanocomposite (N-rGO@TiO₂) using a simple, eco-friendly method and its applications in spectroscopic detection of heavy metal ions such as lead (Pb²⁺), mercury (Hg²⁺), and chromium-VI [Cr(VI)] in potable water. Initially, TiO₂ nanoparticles loaded N doped rGO sheets were fabricated by an ecological method using Gossypium hirsutum (cotton) seeds extract as a green reducing agent. Then, the N-rGO@TiO₂ nanocomposites were subjected for characterizations such as spectroscopic techniques, particle size analysis, zeta potential analysis, and spectroscopic sensing. Notably, the results of this study confirmed that N-rGO@TiO₂ exhibited countless stupendous features in terms of sensing of an analyte. Briefly, the UV-visible spectroscopy and Fourier transform infrared (FTIR) spectroscopy confirmed the successful synthesis of N-rGO@TiO₂. The SEM images showed the wrinkled, folded, and cross-linked network structures that confirmed the surface modification and nitrogen doping in the rGO sheet and synthesis of N-rGO@TiO₂. The EDAX study confirmed the elemental composition of the N-rGO@TiO₂ nanocomposite. Finally, due to the larger surface area, porous nature, high electron mobility, etc. the N-rGO@TiO₂ probe provides the lower detection limit for Pb²⁺, Hg^2+, and Cr (VI) as low as 50 nM, 15 µM, and 25 nM, respectively. Concisely, our study affirms the admirable sensitivity of N-rGO@TiO₂ nanocomposite to the Pb²⁺, Hg^2+, and Cr (VI) in potable water can provide better environmental remediation.