Carbon spheres modified titanium air diffusion cathode for boosting H2O2 and application in disinfection

In situ electrochemical disinfection via H2O2 through two-electron molecular oxygen reduction reaction (2e-ORR) represents a promising strategy for sustainable disinfection. However, its disinfection performance is largely confined by its low selectivity/reactivity towards two-electron oxygen reduction reaction (2e-ORR) for H2O2 production. To tackle this, carbon spheres modified tubular titanium air diffusion cathode (CS@TTC) was developed. It intended to improve interfacial structures for high H2O2 production through a facile hydrothermal carbonation approach. Evolution of morphology and chemical nature of carbon spheres have been systemically investigated under diverse hydrothermal temperature, hydrothermal time and pyrolysis temperature center dot H2O2 accumulation has improved 6.59-fold at CS@TTC compared to the raw base TTC. Both chemical nature of carbon sphere and a superior oxygen mass transfer (0.0284 s(-1)) were responsible for this enhancement. Besides, CS@TTC cathode was used in the electrochemical system for disinfection performance, in which 6.42 log of E. coli was deactivated after 120 min. Hence, this study gives an insight into that the H2O2-based electrochemical disinfection is promising to be a next-generation process.

Automated summary

In situ electrochemical disinfection using H2O2 via the two-electron molecular oxygen reduction reaction (2e-ORR) is a promising method for sustainable disinfection. However, its effectiveness is limited by the low selectivity and reactivity towards 2e-ORR for H2O2 production. To address this issue, a carbon sphere-modified tubular titanium air diffusion cathode (CS@TTC) was developed to enhance interfacial structures and improve H2O2 production. The CS@TTC cathode showed a 6.59-fold increase in H2O2 accumulation compared to the raw base TTC due to the improved chemical nature of the carbon spheres and superior oxygen mass transfer. Additionally, the disinfection performance of the CS@TTC cathode resulted in a 6.42 log reduction of E. coli after 120 minutes, demonstrating the potential of H2O2-based electrochemical disinfection as a next-generation process.