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

Catalytic ozone (O₃ ) 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 O₃ decomposition over the three-dimensional monolithic molybdenum oxide/graphdiyne (MoO₃ /GDY) catalyst. The O₃ decomposition over MoO₃ /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 MoO₃ materials(≤7.1 %). The sp-hybridized carbon in GDY donates electrons to MoO₃ 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 O₃ and the generation of new intermediate species (hydroxyl ⋅OH and superoxo ⋅O₂ ^- ), which significantly lowers the energy barriers of O₃ decomposition (0.57 eV lower than dry conditions).