O-bridged NiSe2/CQDs composite synergistically triggers interfacial electrons transfer to promote H2O2 electrosynthesis

Modulating the electronic structure of electrocatalysts represents a widely employed strategy to enhance the oxygen reduction reaction (ORR) activity and H 2 O 2 selectivity, yet achieving precise control over this process remains challenging. In this work, we introduce oxygen-doped carbon quantum dots (O-CQDs) into NiSe 2 nanoparticles/nanosheets to regulate the electronic structure of Ni active sites. This optimization promotes favorable O 2 adsorption and reduces the energy barrier for • OOH formation, thereby significantly boosting the electrocatalytic production of H 2 O 2 via the two-electron (2e – ) ORR pathway. Combined spectroscopic analysis and density functional theory calculations reveal that the O-bridged interface facilitates electron transfer to surface Ni sites, strengthening O 2 adsorption in an “end-on” configuration and favoring the 2e – ORR mechanism. The resulting O-bridged NiSe 2 /CQDs catalyst exhibits outstanding 2e – ORR performance under alkaline conditions, achieving a high H 2 O 2 production rate of 7458.24 mmol g cat –1 h –1 at 31.25 mA cm –2 and a Faradaic efficiency of 92.88% at 0.5 V. The efficient degradation of the Rhodamine B and Methylene Blue is achieved by utilizing the electrolyte obtained after the H 2 O 2 electrosynthesis process as a Fenton reagent. This study demonstrates that rational tailoring of interfacial charge distribution in hybrid catalysts provides an effective strategy for enhancing catalytic performance, offering a promising design principle for advanced electrocatalysts.