Improvement of photocatalytic activity of nanoparticulate zinc oxide

(Nanowerk News) Researchers from Islamic Azad University, Shahreza branch, and Shahr-e Kord University succeeded in the improvement of crystalline growth and surface modification of ZnO layer in In2O3/SnO2/ZnO catalyst by using network accommodation between zinc and tin oxides and by reducing the inductive tension in the heterojunction of the two oxides (see paper in Ceramics International: "Effect of heterojunction on photocatalytic properties of multilayered ZnO-based thin films").
The modification was used in order to increase the photocatalytic activity of the nanocatalyst. The catalysts synthesized through this method can be used cost-effectively at large scale in the purification of textile industry wastewater after more optimization.
In this research, the two catalysts In2O3/SnO2/ZnO and SnO2/In2O3/ZnO were firstly synthesized, and then they were used in the degradation of an azo dye (light brown solantine) that exists in the wastewater of textile industry. The first catalyst showed higher degradation efficiency in comparison to the second one. In order to optimize the catalysts, silver was used between the layers and finally, the multilayer film of In2O3.Ag/SnO2/ZnO was selected as the best catalyst.
According to Dr. Nasrin Talebian, one of the researchers of the study, the use of network accommodation in order to modify photocatalytic activity of zinc oxide was one of the most important innovations of the study.
“The surface energy of (002) crystallography sheet is more than that of (100) and (101) sheets in thermodynamic equilibrium conditions. Therefore, nanoparticles preferably grow in this direction more than other directions in order to minimize the surface energy,” she stated about the research.
Source: INIC