Rapid Ozone Decomposition over Water‐activated Monolithic MoO3/Graphdiyne Nanowalls under High Humidity

Abstract Catalytic ozone (O 3 ) decomposition at high relative humidity (RH) remains a great challenge due to the catalysts poison and deactivation under high humidity. Here, we firstly elaborate the role of water activation and the corresponding mechanism of the promoted O 3 decomposition over the three‐dimensional monolithic molybdenum oxide/graphdiyne (MoO 3 /GDY) catalyst. The O 3 decomposition over MoO 3 /GDY reaches up to 100 % under high humid condition (75 % RH) at room temperature, which is 4.0 times as high as that of dry conditions, significantly surpasses other carbon‐based MoO 3 materials(≤7.1 %). The sp‐hybridized carbon in GDY donates electrons to MoO 3 along the C−O−Mo bond, facilitating water activation to form hydroxyl species. As a result, hydroxyl species dissociated from water act as new active sites, promoting the adsorption of O 3 and the generation of new intermediate species (hydroxyl ⋅OH and superoxo ⋅O 2 − ), which significantly lowers the energy barriers of O 3 decomposition (0.57 eV lower than dry conditions).