Improving Water Spray Efficacy for Fire Suppression via CO2 Addition at High Pressures and Low Temperatures: Evidence for CO2 Clathrate Hydrate Formation

Enhanced CO2 Sensing by Oxygen Plasma-Treated Perovskite-Graphene Nanocomposites

Carbon dioxide (CO2) is a major greenhouse gas responsible for global warming and climate change. The development of sensitive CO2 sensors is crucial for environmental and industrial applications. This paper presents a novel CO2 sensor based on perovskite nanocrystals immobilized on graphene and functionalized with oxygen plasma treatment. The impact of this post-treatment method was thoroughly investigated using various characterization techniques, including Raman spectroscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. The detection of CO2 at parts per million (ppm) levels demonstrated that the hybrids subjected to 5 min of oxygen plasma treatment exhibited a 3-fold improvement in sensing performance compared to untreated layers. Consequently, the CO2 sensing capability of the oxygen-treated samples showed a limit of detection and limit of quantification of 6.9 and 22.9 ppm, respectively. Furthermore, the influence of ambient moisture on the CO2 sensing performance was also evaluated, revealing a significant effect of oxygen plasma treatment.

An Initial Evaluation on the Adsorption of SO2 and NO2 over Porous Fe3O4 Nanoparticles Synthesized by Facile Scalable Method

In this study, Fe3O4 nanoparticles used as an adsorbent for the removal of toxic gases were successfully synthesized via the facile coprecipitation method. The Fe3O4 nanoparticles displayed a well-defined morphology with the size of ∼10 nm and a porous structure with a specific area of 115.90 m2/g and a wide range of pore sizes. These nanoparticles exhibited effective adsorption abilities upon the exposure to toxic gases. In particular, the amount of 40.5 mg SO2 and 108.5 mg NO2 was adsorbed in 1 g of Fe3O4 nanoparticles after 60 minutes of exposure, making the Fe3O4 nanoparticles become a promising adsorbent for the removal of toxic gases.

Gas storage in "dry water" and "dry gel" clathrates

"Dry water" (DW) is a free-flowing powder prepared by mixing water, hydrophobic silica particles, and air at high speeds. We demonstrated recently that DW can be used to dramatically enhance methane uptake rates in methane gas hydrate (MGH). Here, we expand on our initial work, demonstrating that DW can be used to increase the kinetics of formation of gas clathrates for gases other than methane, such as CO(2) and Kr. We also show that the stability of the system toward coalescence can be increased via the inclusion of a gelling agent to form a "dry gel", thus dramatically improving the recyclability of the material. For example, the addition of gellan gum allows effective reuse over at least eight clathration cycles without the need for reblending. DW and its "dry gel" modification may represent a potential platform for recyclable gas storage or gas separation on a practicable time scale in a static, unmixed system.