Succimer

A crystalline@amorphous MnO₂ (HT@RT) plasma catalyst was successfully constructed in this study to address the problem of odor pollution, especially from volatile organic sulfur compounds (VOSCs) with low olfactory thresholds. Complete conversion of dimethyl sulfide (DMS) at 140 J/L was achieved, and the ozone concentration in the exhaust gas was maintained below 5 ppm. Deeper mineralization of DMS was achieved in the HT@RT sample than in the individual HT and RT samples. A comprehensive analysis of multiple characterization techniques revealed that the HT@RT sample exhibited excellent DMS adsorption capacity, appropriate electric field responsiveness, high oxygen vacancy content, and abundant reactive oxygen species, which play key roles in the degradation of DMS. In addition, the DMS degradation process was investigated using in situ plasma diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy. Combined with the results of gas chromatography-mass spectrometry, degradation pathways for DMS were proposed. The HT@RT sample combined the advantages of both amorphous and crystalline materials, significantly enhancing the activity and stability of the catalyst. Therefore, the crystalline@amorphous structured catalysts constructed in this study not only offer new insights for improving the performance of plasma catalysis but also provide an effective solution for eliminating odorous gases.

Volatile sulfur compounds, such as dimethyl sulfide (DMS), carbonyl sulfide (OCS), and carbon disulfide (CS₂), significantly influence atmospheric chemistry and climate change. Despite the oceans being an important source of these sulfides, the limited understanding of their biogeochemical cycles in seawater introduces considerable uncertainties in quantifying their oceanic emissions and assessing atmospheric OCS budgets. To address this issue, we conducted a comprehensive field survey in the tropical eastern Indian Ocean (EIO) to examine the spatial distributions, source-sink dynamics, and sea-air exchange fluxes of marine DMS, OCS, and CS₂. Our study indicates that nutrients, organic matter, and freshwater input from terrestrial runoff significantly affect most of the source-sink processes of these sulfides in the Bay of Bengal and even the tropical EIO. The resulting sulfide accumulation in seawater combined with high wind speeds establishes the tropical EIO as a considerable direct and indirect atmospheric OCS source. These insights underscore the potentially critical role of marine environments influenced by runoff in contributing to the atmospheric OCS budget. However, by integrating these results with previous field surveys, we believe that actual OCS emissions from tropical oceans exceed some bottom-up box-model simulations, yet fall significantly below those predicted by top-down models, still insufficient to bridge the atmospheric OCS source gap. Our detailed examination of source-sink dynamics offers deeper insights into the marine sulfur cycle and has potential implications for refining future box-models, thus mitigating uncertainties in estimating marine sulfur emissions.