Electrocatalytic ozone decomposition over the entire humidity range with a three-phase system

Abstract

The ever-increasing ground-level ozone pollution threatens the health of both humans and ecosystems. Two-phase catalysts can achieve rapid ozone decomposition at room temperature, yet most show moisture-deactivated performance. Herein, we build a three-phase (gas-liquid-solid) electrocatalytic system for ozone decomposition at the three-phase interface. Almost 100% of ozone decomposition over the entire humidity range (3.1%–92.1% relative humidity) is achieved with no interference from moisture. Amphiphilic carbon cloth as a cathode provides the three-phase interface, promoting ozone diffusion and strengthening the electrochemical reactions. Nitric acid as an electrolyte is also indispensable. It not only suppresses the hydrogen evolution reaction but also generates reducing species, such as ammonia, via the nitrate reduction reaction. Enriched ammonia concentrations at the three-phase interface rapidly reacts with ozone, accelerating its depletion. This work provides a strategy for the development of a moisture-resistant ozone decomposition system and expands on current state-of-the-art ozone decomposition techniques.