2022 Annual Meeting
Integration and Durability of PTFE/Carbon Black Modified Electrodes for Hydrogen Peroxide Generation in an Estrogenic Pollutant Water Treatment System
Hydrogen peroxide (H2O2) plays a significant role in wastewater treatment and environmental remediation applications as it is a versatile and environmentally friendly oxidant with high oxidation potential and no hazardous decomposition products. More than 95 percent of H2O2 produced globally is manufactured by the anthraquinone oxidation process; however, this process cannot be recognized as a green process due to its significant infrastructure and energy requirements. H2O2 production via 2-electron O2 electroreduction is an attractive alternative as it allows for in situ H2O2 production under mild conditions, and the electrocatalysts can be tuned to improve activity and selectivity towards 2-electron O2 electroreduction. Graphite felt (GF) in particular has been used extensively to electrogenerate H2O2 for wastewater treatment applications and electrochemically modified to introduce oxygen-containing functional groups to the carbon surface for enhanced H2O2 production. We sought to explore the effects of modifying carbon electrodes with a polytetrafluoroethylene (PTFE)/carbon black coating on electrolytic H2O2 generation in a novel water remediation system to treat estrogenic contaminants in agricultural runoff. GF electrodes were coated and annealed with a mixture of PTFE and carbon black. The modified cathodes were used to electrogenerate H2O2, and solution samples collected throughout were analyzed by UV-Vis spectroscopy. We found that modified electrodes exhibited H2O2 yield 30 times greater than unmodified electrodes, which is attributed to increased concentrations of surface oxygen behaving as active sites for 2-electron O2 electroreduction. However, repeated uses of a given modified electrode resulted in a 50 percent drop in H2O2 generation by the fourth use as a result of the dislodging of carbon black particles and lack of resiliency of the coating.