Self-Healing NiFe-LDH Enables Efficient Ozone Decomposition over a Wide Humidity Range

Nickel–iron layered double hydroxide (Ni1−xFex-LDH) with different Ni/Fe ratios was prepared by a simple hydrothermal method and evaluated for ozone decomposition under various humidity conditions. In particular, Ni0.8Fe0.2-LDH showed outstanding activity and stability across a wide humidity range and maintained complete ozone conversion for 10 h even at 90% relative humidity. The combined characterization and catalytic results indicate that the cooperative effect of Ni and Fe increases the specific surface area, tunes the metal valence states, and optimizes the humidity-dependent reaction pathway. More importantly, the catalyst shows clear self-healing behavior after ozone exposure, suggesting that the ozone-induced surface reconstruction is at least partly reversible rather than fully destructive. These results identify an efficient Ni1−xFex-LDH catalyst for ozone abatement and provide insight into the dynamic behavior of hydroxyl-rich layered catalysts under oxidizing atmospheres.