Highly efficient two-electron electroreduction of oxygen into hydrogen peroxide over Cu-doped TiO2

Electrosynthesis of hydrogen peroxide (H2O2), as a sustainable alternative to the anthraquinone oxidation method, provides the feasibility of directly generating H2O2. Here, we report Cu-doped TiO2 as an efficient electrocatalyst which exhibits the excellent two-electron oxygen reduction reaction (2e(-) ORR) performance with respect to the pristine TiO2. The Cu doping results in the distortion of TiO2 lattice and further forms a large number of oxygen vacancies and Ti3+. Such Cu-doped TiO2 exhibits a positive onset potential about 0.79 V and high H2O2 selectivity about 91.2%. Moreover, it also shows a larger H2O2 yield and good stability. Density functional theory (DFT) calculations reveal that Cu dopant not only improves the electrical conductivity of pristine TiO2 but reduces the *OOH adsorption energy of active sites, which is beneficial to promote subsequently 2e(-) ORR process.

Automated summary

In this study, Cu-doped TiO2 was reported as an efficient electrocatalyst for sustainable electrochemical synthesis of hydrogen peroxide. The Cu doping induced lattice distortion and the formation of oxygen vacancies and Ti3+ species, leading to improved selectivity and yield of hydrogen peroxide. Theoretical calculations revealed that Cu doping not only enhanced the electrical conductivity of TiO2, but also facilitated the oxygen reduction reaction process.