Ionic–Covalent Bond-Mediated Electron-Rich Lattice Oxygen for Solar-Driven Acetic Acid Abatement

Domestic waste generates volatile fatty acids (VFAs) and emits strong malodors that reduce environmental comfort. The generation of these odor-causing molecules usually occurs in relatively high-humidity conditions, which speed up the deterioration of adsorbents, creating secondary waste from frequent replacement. Herein, we report a lithium-doped manganese dioxide (Li–MnO2) photothermal system that sustainably degrades acetic acid (CH3COOH, a key VFA). Mechanistic studies reveal the ionic bond in Li–O localizes electrons at the oxygen atom, while the covalent bond in Mn–O establishes an efficient electron transport channel. This electron-rich oxygen can cleave the O–H bond in H2O with an ultra-low energy barrier of 0.01 eV, generating dihydroxy groups, which subsequently initiate a nucleophilic attack on the O–H and C–H bonds in CH3COOH molecules. The introduction of light not only efficiently converts the material surface into thermal energy, but it also triggers electron rearrangement. The engineered Li–MnO2 catalyst demonstrates complete CH3COOH degradation at 291 mW cm–2. A modular photothermal purification device demonstrates above 1000 h odor removal efficiency in municipal waste scenario. We anticipate this work will enable perpetual CH3COOH removal from domestic waste without external energy input, offering a sustainable solution for odor control in waste management.