A general strategy to enhance hydrogen peroxide generation via two-electron water oxidation by antimony modification for removal of triethyl phosphate and hexavalent chromium

Abstract

Two-electron water oxidation has attracted more and more attention for H2O2 production. This strategy mainly uses water and does not require bubbling of oxygen gas, which can be widely used in oxygen-deficient environments. Currently, the most important research for two-electron water oxidation is the design of high-efficiency anode materials. Herein, a general method is developed to enhance the activity of two-electron water oxidation for H2O2 production via Sb2O3 modification. This strategy is suitable for a series of electrodes, including carbon fiber paper, graphite plate, WO3, CuWO4 and WO3&CuWO4 composite. The mechanism for Sb2O3 modification toward enhanced H2O2 generation is clearly demonstrated. It should be due to three factors: 1) enhance the reaction kinetic, 2) enlarge the specific surface area and 3) suppress H2O2 decomposition. According to density function calculation, it is firstly found that the Sb optimizes the Gibbs free energy of adsorbed *OH intermediate of its nearby atom, making its adjacent atom (such as W) the active site. Finally, these Sb-modified electrodes are firstly used to produce H2O2 for high-efficiency removal of triethyl phosphate, an environmental pollutant that are difficult to be degraded. It can also be used for the removal of hexavalent chromium, one kind of heavy metal.