Eco-friendly synthesis and applications of graphene-titanium dioxide nanocomposites for pollutant degradation and energy storage

[Display omitted] •Eco-friendly synthesis of graphene-titanium dioxide nanocomposites using orange peel extract.•GTO/NC-2 effectively degrades methyl orange with high catalytic efficiency.•GTO/NC-2 shows excellent reusability and stability over multiple cycles.•Demonstrated high specific capacitance and good retention in supercapacitor applications.•Highlights sustainable approach for environmental and energy storage applications. An innovative, eco-friendly method has been developed to synthesize reduced graphene oxide (rGO) sheets using orange peel extract. Following this, TiO2 nanoparticles are anchored to the rGO sheets through a hydrothermal process, resulting in an rGO/TiO2 nanocomposite (GTO/NC). This study utilized standard characterization techniques to confirm the formation of GTO/NC-1 and GTO/NC-2. Comparative analysis demonstrated that orange peel extract exhibits reducing capabilities compared to other natural reducers. The resulting GTO/NC-1 and GTO/NC-2, specifically GTO/NC-2, enhanced catalytic performance in degrading methyl orange a prevalent organic pollutant in various industrial applications. This nanocomposite achieved a turnover frequency of 0.003 mg MO/mg catalyst/min and displayed remarkable durability, enduring 3.0 cycles with robust first-order rate constants of 0.0193 min−1. Additionally, the electrochemical properties of GTO/NC-1 and GTO/NC-2 as electrode materials were assessed, revealing a specific capacitance of 320.0 Fg−1 at a current density of 1.0 Ag−1 and maintaining about 86.8 % of its initial capacitance after various charge–discharge cycles. These properties highlight the potential of GTO/NC-1 and GTO/NC-2 as both efficient catalysts for environmental remediation and durable materials for energy storage applications, offering substantial benefits for sustainable technology solutions.