HO inducing dissolved oxygen activation and electron donation of pollutants over Fe-ZnS quantum dots through surface electron-poor/rich microregion construction for water treatment.

In common advanced oxidation processes, excess reagents and energy are often added to the reaction system to maintain the continuity of the reaction. These additions result in a large waste of resources and energy, which has become a bottleneck in the development of water treatment technology. In this study, we propose a new strategy to solve this problem based on a novel dual-reaction-center (DRC) Fe-ZnS quantum dots (Fe-ZnS QDs) catalyst that forms a non-equilibrium surface with an electron-polarized distribution. Through experimental and theoretical studies, it was verified that the activation of trace amounts of HO could break the energy barrier for pollutants to transfer electrons. The dissolved oxygen (DO) in the reaction system could be activated by gaining energy on the surface of the Fe-ZnS QDs catalyst, and was converted to O to attack organic pollution. In addition, the pollutants themselves supplied electrons to HO through the surface of the Fe-ZnS QDs catalyst to generate more •OH radicals for pollutant degradation, thus providing two fast paths for pollutant degradation. The system could drive the reaction through a trace amount of HO, thereby activating DO to generate O while effectively using the energy of pollutants. Therefore, the proposed system offers a new direction for the development of environmentally-friendly catalysts and greatly reduces the consumption of resources and energy.