Dual Enhancement of Electrochemical Ozone Production and Chlorine Evolution Reaction over Sulfur‐Doped 3D Ni‐Sb‐SnO2 Electrodes

Why It Matters

The breakthrough delivers a high‑efficiency, low‑energy electrochemical platform that simultaneously generates ozone and chlorine, addressing critical needs for sustainable water disinfection and pollutant degradation.

Key Takeaways

• Sulfur doping raises ozone Faradaic efficiency to 50%
• Chlorine evolution efficiency reaches 95.7% under acid
• Lattice‑oxygen mechanism enabled by sulfur‑induced oxygen mobility
• Overpotential reduced via tuned Cl* adsorption strength
• Continuous‑flow cell sterilizes 99.9% bacteria in tests

Pulse Analysis

Electrochemical ozone generation and chlorine evolution are cornerstone technologies for advanced oxidation processes in water treatment, yet their commercial adoption has been hampered by modest catalyst activity and high energy demand. Conventional metal‑oxide electrodes often suffer from sluggish oxygen‑transfer kinetics and poor selectivity, forcing operators to rely on separate ozone generators and chlorine dosing systems. By unifying these reactions on a single, robust electrode, the industry can simplify plant design, cut capital costs, and reduce the carbon footprint associated with auxiliary chemical production.

The key innovation lies in incorporating sulfur atoms into the Ni‑Sb‑SnO2 lattice, which subtly reshapes the electronic structure and creates oxygen vacancies that accelerate lattice‑oxygen migration. This modification stabilizes critical intermediates such as *OH and *Cl, lowering the activation barrier for both ozone formation and chlorine evolution. In situ Raman and X‑ray absorption studies, complemented by density‑functional theory calculations, reveal that the ozone pathway proceeds via a lattice‑oxygen mechanism, while the chlorine pathway benefits from weakened *Cl adsorption, translating into a 0.3 V reduction in overpotential. The resulting Faradaic efficiencies—50.10% for ozone and 95.70% for chlorine—represent a substantial leap over baseline Ni‑Sb‑SnO2 electrodes.

When deployed in a continuous‑flow stacked cell, the sulfur‑doped electrode delivers near‑complete microbial inactivation, achieving 97.5% kill rates for Escherichia coli and 99.89% for Streptomyces griseus in pilot trials. This performance underscores the technology’s readiness for scale‑up in municipal and industrial water‑reuse facilities, where combined ozone‑chlorine oxidation can target a broad spectrum of contaminants, from organic micropollutants to resistant pathogens. Future work will focus on long‑term durability, integration with renewable power sources, and cost‑optimization of the sulfur‑doping process, positioning the platform as a cornerstone of next‑generation, circular‑economy water infrastructure.