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Chemistry of 2D Materials for Energy Applications
Published in Ram K. Gupta, 2D Nanomaterials, 2022
Charu Goyal, Anuj Kumar, Ram K. Gupta
Several types of 2D materials have been noted in the wake of graphene’s discovery, containing mono-elemental analogues (MEAs) of graphene, transition metal dichalcogenides (TMDs), carbides, nitrides, and carbonitrides (MXene) of transition metals. The typical architecture of popular 2D materials is shown in Figure 1.1. MEAs are 2D materials that are made up of only one kind of element with 2D structures similar to graphene. MX2, in which M is a transition metal atom (including Mo, Nb, V, or W) and X is represented as a chalcogen atom, is the chemical formula for TMDs (including S, Se, or Te). 2D transition metal dichalcogenides have a wide range of applications in high-end electronics, spin-manipulated electronics technology, optoelectronic devices, and energy storage and conversion due to their sturdy spin–orbit coupling and favorable electrical as well as mechanical characteristics [3]. MXenes are typically made by carefully removing the ‘A’ components from MAX phases, which have the chemical stoichiometry of Mn+1AXn (where M is an earlier transition metal, A is a group 12–16 element, and X is carbon or nitrogen). Large electrical conductivity, appropriate hydrophilic behavior, good thermal stability, broad interlayer spacing, with readily adjustable structure have all been discovered in MXenes [4], which makes it a potential material for electrochemical energy storage.
Hg, 80]
Published in Alina Kabata-Pendias, Barbara Szteke, Trace Elements in Abiotic and Biotic Environments, 2015
Alina Kabata-Pendias, Barbara Szteke
Mercury (Hg), a metal of the group 12 in the periodic table of elements, is the only metal that exists in the liquid state in natural conditions. Its average content in the Earth’s crust is 0.07 mg/kg, and is much lower in igneous rocks (0.004–0.008 mg/kg) than in sedimentary rocks (0.01–0.4 mg/kg). It is likely to be concentrated in argillaceous sediments. Contents of Hg in coal vary within the range of 0.2–10 mg/kg, and in fly ash, the content is around 0.01 mg/kg.
Cadmium and Lead: Contamination
Published in Brian D. Fath, Sven E. Jørgensen, Megan Cole, Managing Global Resources and Universal Processes, 2020
Gabriella Kakonyi, Imad A.M. Ahmed
Cadmium (Cd) and lead (Pb) are transition metals that have no known vital or beneficial role in the human body or health. Cadmium (atomic number 48, atomic mass 112.4 g mol−1) belongs to Group 12 of the periodic table, possessing somewhat similar chemical properties as zinc and mercury. Lead (atomic number 82, atomic mass 207.2g mol−1) is a member of Group 14 in the periodic table, which also includes C, Si, Ge, and Sn.[1] The most predominant oxidation state of Cd and Pb under normal environmental conditions of temperature and pressure is +2. In organolead chemistry, the oxidation state (+4) of Pb is remarkably dominant.[2] Both Cd and Pb are considered to form stable oxidation states as divalent Cd2+ and Pb2+ ions in inorganic compounds. Their biological toxicity appears to be determined by their availability for ligand exchange and chelation properties.[3–6] The chemical similarity of Cd and Pb to certain alkaline earth metals such as calcium; their ability to form highly insoluble inorganic salts (e.g., phosphate, carbonate, sulfate), organometallic complexes, or free hydrated ions; and their increased affinity to biological donors (e.g., proteins) play an important role in their transport in the environment and toxicity in biological systems.[2,7,8]
Bacillus altitudinis MT422188: a potential agent for zinc bioremediation
Published in Bioremediation Journal, 2022
Maryam Khan, Munazza Ijaz, Ghayoor Abbas Chotana, Ghulam Murtaza, Arif Malik, Saba Shamim
Zinc (Zn2+) is one of the essential heavy metals that belongs to group 12 of the periodic table of elements. It exists as a positively charged, divalent ion in nature, which interacts with various negatively charged ions. It is also able to form soluble complexes by chelating organic compounds present in the body, with its role being significant in more than 200 proteins and enzymes (Cuajungco, Ramirez, and Tolmasky 2021). In bacteria, Zn tends to support basic survival as well as assist in the pathogenicity of some pathogens (Kandari, Joshi, and Bhatnagar 2021). In the environment, the toxic concentrations of Zn2+ can arise from various anthropogenic activities that can render harmful consequences. Soils polluted by Zn2+ can affect plants, animals and microbes, which can also lead to the contamination of water sources (Gautam et al. 2016).
Distributions of cadmium, zinc, and polyphenols in Gamblea innovans
Published in International Journal of Phytoremediation, 2019
Misuzu Sakurai, Rie Tomioka, Akiko Hokura, Yasuko Terada, Chisato Takenaka
Takenaka et al. (2009) reported high concentrations of Cd and Zn in G. innovans bark, petioles, and veins. However, the behavior of Cd and Zn within G. innovans has not been clarified. Both Zn and Cd belong to Group 12 in the periodic table and their chemical properties are said to be similar. Zinc is an essential element for organisms, but Cd has not been shown to be essential. Therefore, plants must control the translocation and localization of Cd and Zn in order to maintain normal physiological function. To determine whether G. innovans can distinguish between Cd and Zn, we studied their distributions throughout various organs. High-resolution micro-X ray fluorescence (µ-XRF) analysis was utilized to investigate distributions at the subcellular level. Because a previous study suggested oxalic acid as a candidate for chelation with Cd in G. innovans (Takenaka et al. 2009), we also attempted to determine the chemical form of Cd in the bark and leaves of G. innovans via micro X-ray absorption near-edge structure (µ-XANES) analysis.
1-(3-Chlorophenyl)-4-(3-phenylseleno propyl) piperazine (L); synthesis, spectroscopic characterization, DFT studies, antimicrobial evaluation and its reactivity toward group 12 metal chlorides
Published in Journal of Coordination Chemistry, 2018
Muzzaffar A. Bhat, Shabir H. Lone, Sanjay K. Srivastava
Group 12 metals (Zn, Cd, Hg) are considered to be the most covalent and chalcophilic in the periodic table. The chemistry of group 12 metal chalcogenides has been extensively studied due to their applications in the field of nanomaterials [1] and opto-electronics [2]. Due to their importance, the preparation and structural characterization of group 12–16 complexes as single-source stoichiometric precursors have continued to draw the attention of chemists. Various research groups have reported that [M(ER)2] complexes (M = Zn, Cd or Hg; E = S, Se or Te; R = aryl) can be utilized as such precursors [3]. However, these compounds are generally polymeric in the solid state, very difficult to isolate in the crystalline form, relatively insoluble in hydrocarbon solvents and therefore, very difficult to be purified and characterized [4]. Organoselenium chemistry has been exploited to present an extensive range and high diversity of products that find an inevitable place in the area of synthetic applications [5, 6]. In addition, organoselenium compounds are known to be suitable antioxidants because of their unique ability to imitate the enzymatic activities of glutathione peroxidase (Gpx) that catalyzes the decomposition of hydroperoxides in various biochemical reactions [7, 8]. Organoselenium compounds containing selenium in bivalent oxidation state play a prominent role in coordination chemistry [9, 10]. An extensive use of organoselenium compounds in semiconductors and metal organic chemical vapor deposition techniques consign these compounds a noticeable position in electronic chemistry [11, 12]. A number of methods [13–17] have been developed to obtain an array of aryl/alkyl monoselenides and symmetrical diselenides [18–20]. Symmetrical dialkyl/diaryl monoselenides have also been prepared by the cleavage of dialkyl/diaryl diselenides [21–23], while other methods use transition metal complexes [24–26]. Synthesis, ligation behavior and applications of N-{2-(4-methoxyphenyltelluro)ethyl}morpholine with palladium(II), half-sandwich ruthenium(II) complexes of N-{2-(arylchalcogeno)ethyl}morpholine as useful catalysts for oxidation of alcohols and rhodium(III) complexes of N-{2-(arylseleno/telluro)ethyl}morpholine as catalysts suitable for transfer hydrogenation of ketones have been reported by Singh and Singh. Recently, the same group carried out the synthesis and structural chemistry of N-{2-(arylthio/seleno)ethyl}morpholine/piperidine-palladium(II) complexes as potent catalysts for the Heck reaction [27].