Reduced Graphene Oxide (rGO)–Sn Modified Graphite Felt for Enhanced Electro-Oxidation Degradation of Congo Red Dye

Developing highly efficient and robust catalysts as anode materials is crucial for improving the electrocatalytic degradation of dye wastewater, yet it remains a significant challenge. Here, a reduced graphene oxide-tin (rGO–Sn) nanocomposite was synthesised as an advanced anode material and applied to a low-cost electrode (graphite felt) through a dip-coating method. The physico-chemical and electrochemical analyses were performed to elucidate the properties and validate the successful synthesis of nanomaterials and modified electrodes. Benefitting from the incorporation of highly conductive rGO together with high oxygen evolution potential (OEP) of Sn, the rGO–Sn modified GF exhibits improved electrocatalytic properties by demonstrating lower charge transfer resistance, Rct (4.601 Ω), higher specific capacitance (0.056 mF cm–2) and OEP at 1.490 V when compared with unmodified graphite felt (38.664 Ω, 0.033 mF cm–2 and 1.253 V). The improvement of electrochemical properties results in enhanced efficiency in electro-degradation performance, achieving a 92.44 ± 0.94% removal of the dye Congo red after 2 h of reaction in contrast to the 60.14 ± 0.71% removal by unmodified GF. Moreover, the enhanced mechanical strength contributed by rGO and the elevated oxidation resistance provided by Sn, which safeguards the underlying substrate, significantly prolongs the service lifetime of the modified GF to 6.8 h, as compared to the unmodified GF’s 1.2 h. This study opens up new avenues for improving the performance of low-cost electrodes through an easy coating method of rGO–Sn since cost is a major concern for the EO process.