Highly efficient photocatalytic degradation of unsymmetrical dimethylhydrazine with 001-TiO2/CeO2 S-scheme heterojunction

Unsymmetrical dimethylhydrazine is a high-energy liquid rocket fuel widely utilized in the aerospace field. Its highly toxic nature poses a significant threat to the ecosystem and human health, necessitating the urgent development of efficient and environmentally friendly treatment technologies. In this study, a (001) crystal facet-dominated 001-TiO 2 /CeO 2 S-scheme heterojunction was constructed via a solvent hydrothermal-photoassisted method. Under simulated solar light irradiation, the catalyst demonstrated a degradation efficiency of 98.4 % for high-concentration Unsymmetrical dimethylhydrazine wastewater (100 mg/L) within 140 min, while effectively decomposing highly toxic intermediates with a mineralization rate reaching 84.5 %. This is attributed to the synergistic interaction between the crystal facet effect and the S-scheme heterojunction, which significantly enhances the spatial separation and transfer of photogenerated carriers. The intermediate products were identified using solid-phase microextraction coupled with gas chromatography-mass spectrometry (SPME-GC–MS), revealing the possible degradation pathways of Unsymmetrical dimethylhydrazine and elucidating the reaction mechanism. This study offers a viable approach for the efficient degradation of Unsymmetrical dimethylhydrazine wastewater, offering significant reference value for advancing wastewater treatment in the aerospace industry.