Graphene-Based Catalytic Surfaces Decorated with Au and Cu Nanoparticles: A Model Approach toward e‑Waste-Derived Catalysts.

The increasing demand for sustainable technologies and resource efficiency is driving the development of materials that can both mitigate CO2 emissions and recover valuable metals from e-waste. In this work, we report a simple and environmentally friendly approach for fabricating catalytic surfaces based on laser-reduced graphene oxide (rGO) decorated with gold or copper nanoparticles (Au or Cu NPs). The process involves laser reduction of graphene oxide, followed by immersion in aqueous Au3+ or Cu2+ model solutions, simulating metal leachate from an e-waste recovery process. Morphological and chemical analyses (SEM and XPS) confirm the formation of metallic nanoparticles. The resulting metal@rGO surfaces were tested for CO2 photothermo-catalytic conversion under simulated solar irradiation, achieving conversion efficiencies above 40%, with CO and CH4 as the main products. Both catalytic surfaces displayed comparable activity and good stability over three consecutive cycles. This method integrates CO2 conversion with metal recycling, offering a promising route toward circular catalytic materials.