rGO nickel matrix composites with high ozone degradation efficiency under high humidity

Abstract

Low stability or deactivation of materials under high humidity limits the development of ozone removal via catalytic degradation. To address this challenge, a novel material comprising Ni₂(CO₃)(OH)₂ (NiCH) that encapsulates a reduced graphene oxide (rGO) microsphere (NiCH–rGO) with excellent ozone removal was studied herein. The postprocessing catalyst exhibits a stable ozone degradation efficiency of 99% and excellent stability over 12 h under a relative humidity of 60% at a space velocity of 900 L h⁻¹. The mechanism for promoting ozone removal can be summarized as follows: On the one hand, rGO promotes the degradation of ozone via a bond formed between rGO and NiCH, which increases the internal charge transfer of NiCH–rGO. On the other hand, the introduction of rGO decreases the average valency of Ni from 2.42 to 2.37, which enhances the adsorption behavior of ozone. Further, density functional theory and quartz crystal microbalance demonstrated that an appropriate rGO concentration reduced the adsorption energy for ozone and water adsorption capacity. Therefore, the method for improving the properties of catalysts has provided a new approach to designing high-efficiency catalysts.