Gu H, Hao X. Electrolytic coloration below 0°C and spectral properties of ammonium alum crystals using a pointed anode.
SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2015;
146:273-276. [PMID:
25819315 DOI:
10.1016/j.saa.2015.03.066]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2014] [Revised: 02/05/2015] [Accepted: 03/05/2015] [Indexed: 06/04/2023]
Abstract
Ammonium alum crystals are colored electrolytically below 0°C and under various voltages using a pointed anode and a flat cathode. SO2(-), O3(-), O2(-), O(-) hole-trapped centers and O(0), O(2-), H(+) radicals are produced in colored ammonium alum crystals. The absorption bands of the SO2(-) and O3(-) hole-trapped centers are observed in the absorption spectra of the colored ammonium alum crystals. The hole-trapped centers and radicals come mainly from the electric-field-induced decomposition of the SO4(2-) radicals and crystalline water molecules. Current is measured during electrolytic coloration. Electron exchanges from electrons and small charged radicals to electrodes induce complete current.
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