Selenium Nanoparticles: Characteristics, Production, and Applications Publisher



S Rahimzadeh SARA ; M Hosseini MINA ; Mh Yazdi Mohammad HOSSEIN
Source: Published:2024

Abstract

Swedish chemist Jons Jacob Berzelius discovered selenium in 1817. While initially assumed by scientists as toxic, it was proved in 1950 that selenium plays an essential role in living organisms. Since organisms are unable to produce selenium, this element enters the body via dietary intake. Selenium exists in nature in two major forms; inorganic, which occurs in different oxidation states, including selenite (SeO3 −2), selenide (Se2−), selenate (SeO4 −2), and elemental selenium (Se0); and organic, including selenomethionine and selenocysteine (1). In the aforementioned inorganic forms, the transition from one state to another occurs easily and is affected by several factors, including redox potential, oxygen concentration, pH, and humidity. Elemental selenium, which harbors the least toxicity, is formed through the reduction of other inorganic forms in biochemical cycles (2). Regarding its polymorphic structure, two forms of crystalline and amorphous structures exist in nature. The crystalline form includes monoclinic selenium (m-Se), which is red and consists of Se8 rings in three allotropic forms (α, β, and ɣ), as well as trigonal selenium (t-Se). Trigonal selenium is black and is known as the most stable crystalline form of selenium at room temperature. The non-crystalline forms of selenium include vitreous, red amorphous, and black amorphous selenium (3). © 2024 Elsevier B.V., All rights reserved.