Nitrogen and oxygen co-doped graphite felt gas diffusion electrodes for efficient hydrogen peroxide electrosynthesis

Abstract

In order to improve the efficiency and reusability of gas diffusion electrodes for hydrogen peroxide (H2O2) electrosynthesis, we modified the graphite felt with nitric acid and constructed nitrogen-oxygen co-doped graphite felt/polytetrafluoroethylene/gas diffusion electrodes. The graphite felts before and after nitric acid modification were characterized by SEM, contact angle measurements, FTIR, and XPS, which showed that nitric acid modification resulted in a significant increase of oxygen- and nitrogen-containing functional groups (such as carboxyl groups and pyridinic nitrogen), which could improve the H2O2 yield and current efficiency. The H2O2 yield of the electrode prepared under the optimized modification conditions can reach 42.2 mg·L−1·cm−2, and the current efficiency can be maintained at about 80.0%. The electrode shows relatively stable performance of H2O2 electrogeneration during 13 cycles, and has a promising application prospect.