Melamine sponge templated synthesis of nickel nanoparticles encapsulated in B, N co-doped carbon nanotubes towards the selective electrosynthesis of hydrogen peroxide

Abstract

Hydrogen peroxide is a versatile and environmentally friendly oxidant. However, its centralized anthraquinone production method triggers considerable cost, energy consumption, and safety issues. The electrochemical synthesis of H₂O₂via a two-electron oxygen reduction reaction (2e⁻ ORR) provides a new strategy for decentralized H₂O₂ production to meet the end-user demands. Here, we report the synthesis of Ni nanoparticles encapsulated in B, N co-doped carbon nanotubes (Ni@B/N-CNTs-MS) as an efficient electrocatalyst for H₂O₂ synthesis. Such B, N co-doped configuration achieves both high activity and selectivity towards 2e⁻ ORR in alkaline electrolytes, affording a high H₂O₂ production rate of 690 ± 17 mmol g_cat⁻¹ h⁻¹ with ∼90% selectivity. The produced H₂O₂ enables almost 100% degradation of RhB pollutants with a concentration of 30 ppm. Theoretical calculations unveil that the C atoms adjacent to B and N atoms are the active sites with the optimal binding strength of *OOH intermediates that are generated on metallic Ni sites, collectively responsible for the superior 2e⁻ ORR performance.