Quantum mechanics

Reaction rate constant

Catalysis

Chemical physics

Photochemistry

Synergistic catalysis

Materials science

Sulfite

Telecommunications

Computer science

Inorganic chemistry

Redox

Combinatorial chemistry

Physics

Nanotechnology

Organic chemistry

Degradation (telecommunications)

Sulfite oxidase

Catalytic cycle

Radical

Kinetics

Crystallography

Chemistry

Applied Catalysis B Environment and Energy

Sulfite has been recently recognized as a source of radicals for oxysulfur radical-based advanced oxidation process due to its low cost and low toxicity. Inspired by sulfite oxidase enzyme, we demonstrate single Fe atoms confined in two-dimensional MoS2 nanosheets (FexMo1-xS2) as highly reactive catalysts for heterogeneous activation of sulfite, thereby promoting efficient oxidative degradation of propranolol in water. Highest propranolol degradation efficiency of ∼90 % was observed at pH 4.0. The Fe or Mo sites of FexMo1-xS2 activate sulfite via the Fe2+/Fe3+ or Mo4+/Mo5+/Mo6+ redox cycle. More importantly, the synergistic catalysis involving the Fe and Mo sites play an essential role. SO5− is the major radical responsible for propranolol degradation with the 2nd-order rate constant of (1.1 ± 0.6)×107 M−1 s−1. Furthermore, the FexMo1-xS2/sulfite system is capable of degrading a wide range of recalcitrant organic pollutants and operating in a real water environment, suggesting its great potential in practical water treatment applications.

Single Fe atoms confined in two-dimensional MoS2 for sulfite activation: A biomimetic approach towards efficient radical generation