High-efficiency visible-light photocatalytic H2O2 production using CdSe-based core/shell quantum dots

Abstract

Photocatalytic production of hydrogen peroxide (H₂O₂) has received great attention as a promising route for sustainable solar fuel. In this work, we demonstrate that quantum dots (QDs) can be explored as a useful photocatalyst for high-efficiency photocatalytic production of H₂O₂ under visible-light with a record-high concentration of 126 mmol L⁻¹. By band structure and wavefunction engineering, QDs exhibit an enhanced stability in an oxidized and humid environment. An oil/water two-phase system is designed to realize spontaneous separation of the H₂O₂ formed to the aqueous phase and of the organic by-products formed to the oil phase. By electron paramagnetic resonance (EPR) measurements, ˙O₂⁻ radicals are generated from QDs in the oil phase and transferred to the water phase immediately. The results in this work show that QDs with a rational surface and structure design can serve as an outstanding photocatalyst for the production of H₂O₂ under visible-light.