Low-consumption water purification: Trace H2O2 triggering H2O2 generation through pollutant utilization on non-equilibrium ZnS surface

Abstract

A low-consumption water purification system is firstly constructed based on a new dual-reaction-center (DRC) catalyst molybdenum-doped zinc sulfide (Mo-ZnS, MZS) with a confined nonequilibrium surface. The extremely strong electron trapping ability of the Mo site is realized by the substitution of Mo for ZnS lattice. In this way, the electrons of emerging contaminants (ECs) are efficiently transferred to the nonequilibrium surface through the oriented interface process (Mo-S-Zn bond bridge), and obtained by the natural dissolved oxygen (DO) to generate hydrogen peroxide (H2O2) under trace H2O2 trigger without light and electricity assistant. The highest yield of H2O2 is even up to ∼230 % of the initial value, and the ECs removal can reach 100 % within 60 min, which is far superior to conventional Fenton catalysts. This work realized the efficient utilization of the contaminant electrons through the construction of Mo-S-Zn bond bridge, which greatly reduced the energy consumption of water purification and improved the resourcefulness of ECs.