Cadmium-based materials with various hydroxide to carbonate ratios and their composites with graphite oxide were synthesized by a fast and simple precipitation procedure and then used as H2S adsorbents at ambient conditions in the dark or upon a visible light exposure. The structural properties and chemical features of the adsorbents were analyzed before and after hydrogen sulfide adsorption. The results showed that the high ratio of hydroxide to carbonate led to an improved H2S adsorption capacity. In moist conditions cadmium hydroxide was the best adsorbent. Moreover, it showed photoactive properties. While the incorporation of a graphene-based phase slightly decreased the extent of the improvement in the H2S adsorption capacity in moist conditions caused by photoactivity, its presence in the composites enhanced the performance in dry conditions. This was linked to photoactivity of CdS that can split H2S resulting in the formation of water in the system. The graphene-based phase enhanced the electron transfer and delayed the recombination of photoinduced charges. Carbonate-based materials showed a very good adsorption capacity in dark conditions in the presence of moisture. Upon the light exposure, CdS likely photocatalyzes the reduction of carbonate ions to formates/formaldehydes. Their deposition on the surface limits the number of sites available to H2S adsorption.
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http://dx.doi.org/10.1016/j.jcis.2015.02.021 | DOI Listing |
Micromachines (Basel)
December 2024
Department of Optometry, Faculty of Allied Health Sciences, University of Sri Jayewardenepura, Nugegoda 10250, Sri Lanka.
Gas sensors play a vital role in detecting gases in the air, converting their concentrations into electrical signals for industrial, environmental, and safety applications. This study used density functional theory methods to explore the mechanism and sensitivity of a PdO-graphene composite sensor towards various gases (CO, NO, NO, HS, and Cl). All calculations, including structure, energy, and frequency optimizations, were performed using the Gaussian software with appropriate configurations and basis sets.
View Article and Find Full Text PDFACS Omega
January 2025
H.E.J. Research Institute of Chemistry, International Center for Chemical and Biological Sciences, University of Karachi, Karachi 75270, Pakistan.
The rising level of toxic gases in the environment poses a high demand for efficient gas sensing materials. MXenes, an emerging class of two-dimensional (2D) materials, have gained significant interest in this area for having an active-site rich structure, tunable surface properties, and remarkable stability. Herein, an extensive density functional theory (DFT) study is conducted to investigate the sensing properties of pristine and Au-functionalized TiC MXene for five toxic gas molecules: CO, COCl, HS, NH, and NO.
View Article and Find Full Text PDFPhys Chem Chem Phys
January 2025
Centre for Research in Molecular Modeling, Concordia University, Montreal, Canada.
The capture of toxic chemicals such as NH, HS, NO and SO is essential due to the tremendous threats they pose to human health and the environment. The M-MOF-74 family of metal-organic frameworks has recently gained attention as a promising category of sorbent materials for the capture of toxic chemicals; however, no clear and comprehensive relationships have been established between the capability of the M-MOF-74 to capture all target toxic chemicals and their properties such as the nature and magnetic state of the metal sites. Density-functional theory (DFT) is employed to investigate the binding energy of target molecules on M-MOF-74 with different metals including Mg, Ti, V, Cr, Mn, Fe, Co, Ni, Cu and Zn.
View Article and Find Full Text PDFEnviron Res
January 2025
Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou, 510640, China; CAS Key Laboratory of Renewable Energy, Guangzhou, 510640, China; Guangdong Provincial Key Laboratory of High-Quality Recycling of End-of-Life New Energy Devices, Guangzhou, 510640, China. Electronic address:
Hydrogen sulfide (HS) is a major air pollutant posing a serious threat to both the environment and public health. In this study, a novel nitrogen-rich biocarbon that effectively removes HS was produced from a mixture of sewage sludge and pine sawdust using melamine as nitrogen source. Compared with pristine biocarbons, nitrogen (N)-doped biocarbons possessed an adjustable porosity, e.
View Article and Find Full Text PDFR Soc Open Sci
January 2025
Institute of Southeast Vietnamese Studies, Thu Dau Mot University, Thu Dau Mot, Binh Duong, Vietnam.
The potential applications of low-dimensional materials continue to inspire significant interest among researchers worldwide. This study investigates the properties of one-dimensional AlSi monolayers, specifically AlSi nanoribbons, and their adsorption behaviour with CO and HS molecules. The electronic, magnetic and optical properties of these systems are calculated using density functional theory and the Vienna Ab initio Simulation Package.
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