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Oxide Nanoparticles in Heterogeneous Catalysis
Published in Varun Rawat, Anirban Das, Chandra Mohan Srivastava, Heterogeneous Catalysis in Organic Transformations, 2022
Garima Sachdeva, Jyoti Dhariwal, Monika Vats, Varun Rawat, Manish Srivastava, Anamika Srivastava
Diaryl selenides act as an important reagent in catalysis and organic synthesis. Rao et al. reported the use of CuO nanoparticles for the formation of carbon–selenium bonds. Treatment of aryl halide with diaryl diselenide under ligand-free conditions afforded diaryl selenide in high yield. Catalyst is environmentally benign, inexpensive, reusable, and effective [22].
Most Promising Solar Technologies
Published in Anco S. Blazev, Solar Technologies for the 21st Century, 2021
Also, and very importantly, selenide provides excellent uniformity, which diminishes the number of recombination sites in the bulk material, thus improving the quantum and conversion efficiencies of thus manufactured solar cells and modules.
Determination of Metals in Soils
Published in T. R. Crompton, Determination of Metals and Anions in Soils, Sediments and Sludges, 2020
The fate of selenium in natural environments such as soil and sediments is affected by a variety of physical, chemical and biological factors which are associated with changes in its oxidation state. Selenium can exist in four different oxidation states (-II, 0, IV and VI) and as a variety of organic compounds. The different chemical forms of selenium can control selenium solubility and availability to organisms. Selenate (Se(VI)) is the most oxidised form of selenium, is highly soluble in water and is generally considered to be the most toxic form. Selenite (Se(IV)) occurs in oxic to suboxic environments and is less available to organisms because of its affinity to sorption sites of sediment and soil constituents. Under anoxic conditions, elemental selenium and selenide(-II) are the thermodynamically stable forms. Elemental selenium is relatively insoluble, and selenide(-II) precipitates as metal selenides(-II) of very low solubility. Organic selenium(-II) compounds such as selenomethionine and selenocystine can accumulate in soil and sediments or mineralise to inorganic selenium. Therefore, Se(VI), Se(IV) and organic selenium(-II) are the most important soluble forms of selenium in natural environments.
Photothermal and adsorption effects of silver selenide nanoparticles modified by different surfactants in nursing care of cancer patients
Published in Science and Technology of Advanced Materials, 2020
Xingju Yang, Chen Wang, Xiaoxu Zhang, Yue Wang, Feng Gao, Lixia Sun, Wenli Xu, Changxiu Qiao, Guiqin Zhang
Metal selenides have recently attracted increasing attention because of their excellent optical properties, easiness in surface-functionalization and stability; therefore, they have been widely used in photocatalysis, optoelectronics, and energy storage [9–13]. Particularly, silver selenide possesses good biocompatibility and high efficiency in converting light to heat, making it a promising material in photothermal therapy of cancer patients [14–16]. However, there are several issues that need to be concerned for cancer treatment based on PTT. Firstly, the insufficient light penetration depth may lead to incomplete elimination of cancer cells, which is the main hidden danger of thorough cancer treatment [17,18]. Secondly, the dispersibility of nanomaterials is also a problem to be solved [1,19]. Last but not least, the shortcomings of monotherapy cannot be ignored, current antitumor research tends to favor multiple approaches [20,21]. The combination of photothermal and chemotherapy can solve the hidden danger of recurrence in single PTT, and it is necessary to use photosensitive materials to explore more comprehensive treatment methods [22]. Recently, Li et al. prepared the Ag2Se quantum dots by the introduction of bovine serum albumin (BSA) as dispersant [23]. The Ag2Se@BSA composite showed good dispersibility, high biocompatibility and remarkable photothermal conversion. However, the drug delivery and photothermal therapy of Ag2Se@BSA need to for further combine with the extra mesoporous silica nanoparticles.
Se(IV) oxidation by ferrate(VI) and subsequent in-situ removal of selenium species with the reduction products of ferrate(VI): performance and mechanism
Published in Journal of Environmental Science and Health, Part A, 2020
Selenium existed in the environment in various oxidation states such as elemental (Se0), selenide (Se2−), selenite (SeO32−), and selenate (SeO42−). Among oxyanions, selenite is more toxic than selenate.[5] When selenium contamination occurs in wastewater and drinking water systems, it poses a potential threat to the water system.[6] Therefore, removing selenium especially Se(IV) has aroused great interest and concern in countries around the world in recent years.[7]
Influence of pH of the electrolyte on the formation and properties of electrodeposited ZrSe2 thin films
Published in Inorganic and Nano-Metal Chemistry, 2022
A. Panimaya Valan Rakkini, K. Mohanraj
The transition metal diselenides have attracted considerable attention during the past few years.[1–4] These MX2 (M = transition metal; X = chalcogen) compounds are formed by a layer of transition metal atoms between two layers of selenium atoms. There is a strong covalent bonding within the layers, but a weak Vander Waals bonding between them.[5–8] These materials are used in diverse applications such as catalysis,[9] batteries,[10] and lubricants[11] recently; these materials have found potential use in the fabrication of photo electrochemical (PEC) solar cell for solar energy conversion.[12–14] However, the electronic industry needs high quality, flexible, and consequently thin semiconductor materials in order to realize devices in situations where standard silicon chips cannot work due to expense and geometry. So far research has focused on organic materials[15,16] because of their potentially low cost. But their poor mobility has prompted several groups to look for inorganic alternatives[17,18] i.e., semiconducting layered transition-metal dichalcogenides thin films. It has also been realized that selenides are more efficient as solar cell materials than sulfides.[19] In light of this realization, the deposition of zirconium diselenide thin films by electrodeposition technique and the fabrication of PEC cell have attracted more attention.[20] ZrSe2 has interesting semiconducting properties and also it exhibits switching and memory effects. Zirconium diselenides show direct and indirect band gap of 1.65 and 1.2 eV, respectively.[21] The effect of annealing in ZrSe2 reduces the band gap energy from 1.5 to 1.38 eV which has been reported in literature.[22,23]