Electrochemical degradation of methyl red in zinc hydroxide and zinc oxide thin films, physical and chemical activation

• Published in: Materials chemistry and physics Vol. 280; p. 125793
• Main Authors: Ahmad, Ahmad A., Al-Bataineh, Qais M., Aljarrah, Ihsan A., Telfah, Ahmad D.
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 15.03.2022; Elsevier BV
• Subjects: Annealing; Circuits; Crystallization; Decoloring; Decolourization efficiency; Degradation; Metal hydroxides; Optical properties; Thin films; Zinc hydroxide; Zinc oxide; Zinc oxides; Thin films; Zinc oxide; Decolourization efficiency; Zinc hydroxide; Optical properties
• ISSN: 0254-0584; 1879-3312
• DOI: 10.1016/j.matchemphys.2022.125793

The experimental and ab initio results on structural, optical, and electronic properties of Zn(OH)2 and ZnO thin films (TFs) at various annealing temperatures are reported. The as-grown TF consists of Zn(OH)2 while annealing them at temperatures higher than 300 °C yields high-quality ZnO. The films were highly crystallized in a hexagonal structure with (200) orientation by XRD analysis. The evaluated optical band gap energies of Zn(OH)2 and ZnO TFs were 3.955 and 3.286 eV, respectively, and agree well with Vienna ab initio hybrid functional HSE06 density of states calculations. The material activation of ZnO and Zn(OH)2 TFs in electrochemical degradation catalyses of methyl red in water proven that ZnO TFs have higher decolourization efficiency than Zn(OH)2 TFs. The electrochemical circuit used was performed under experimental conditions of 12 V voltage difference and 0.3 A current. •Zinc oxide and zinc hydroxide thin films are interrelated with the role of hydrogen and hydroxide in ZnO.•Zn(OH)2 coating is usually used as a galvanic coating to prevent corrosion of metal substrates.•ZnO and Zn(OH)2 thin films activation performed in electrochemical degradation catalyzed Methyl red (MR) in water.•ZnO thin film has higher decolourization efficiency compared to that of Zn(OH)2 thin film.•The experimental and the computational ab intio hybrid functional HSE06 density of states of bandgap energies are comparable.