Rational engineering WO3-X/CNTs@carbon fiber membrane for the high-efficient produce H2O2 via electrochemical two-electron water oxidation route

The electrochemical two-electron water oxidation reaction (2e-WOR) offers a promising avenue for hydrogen peroxide (H 2 O 2 ) production. It is crucial to design electrocatalysts with high selectivity, yield, resource abundance, and environmental friendliness. In this paper, as a new generation 2e-WOR electrocatalyst, the WO 3-X /CNTs@carbon fiber membrane nanostructure with abundant oxygen-rich vacancy (O V ) has been discovered by a series of test techniques including XRD, FE-SEM, TEM, FT-IR, Raman and XPS, comprising interconnected carbon nanotubes and carbon fibers enveloped in WO 3 nanorods with oxygen-rich vacancies. By comparing the specific surface area of WO 3-x /CNTs@carbon fiber membrane at different temperatures, it was observed that the maximum value is 44.09 m 2 /g when the mass ratio of AMT to PAN was 3:2 at 600 °C. Furthermore, the WO 3-X /CNTs@carbon fiber membrane can be directly utilized as an independent electrode. The electrochemical performance test revealed that the Faraday efficiency of the WO 3-X /CNTs @CF-600-2 can reach 54 % (2.48  V vs RHE (reversible hydrogen electrode)), while the H 2 O 2 yield can achieve 10.3 μmol· min −1 ·cm −2 , nearly ten times higher than that of pure WO 3 . Furthermore, the stability testing demonstrated that after 12 h, the WO 3-X /CNTs @CF-600-2 exhibited excellent stability with minimal change in its Faraday efficiency. This enhancement is attributed to the improved selectivity of WO 3 , excellent electrical conductivity, and mass transfer performance of carbon fiber. Finally, we proposed a mechanism for 2e-WOR and provided some perspectives on this reaction along with summarizing recent discoveries.