ZnO-TiO2 nanocomposite materials: fabrication and its applications

Abstract

Zinc oxide (ZnO) is one of the most commonly used semiconductor materials for various applications, namely as photocatalysts, gas sensors, antimicrobial substances, and photovoltaic cells. The performance of the particles is greatly influenced by the morphology and the optical properties of the particles itself. To improve the performance of ZnO, one method which can be applied is by doping support with other semiconductor materials, such as TiO2. This is caused by electron transfers between ZnO and TiO2 which are able to enhance the stability of ZnO and the electron mobility of TiO2. Therefore, the electron-hole recombination can be inhibited by this mechanism. Fabrication of ZnO-TiO2 can be prepared by several methods, which is gas or liquid phases and solid phase. Spray pyrolysis, chemical vapor deposition, micro-arc oxidation, electrospinning and electron beam evaporation are preparation method for gas-phase synthesis, while sol-gel, hydrothermal, precipitation, solution combustion, pulse plating, and wet impregnation are for liquid phases. In this study, the fabrication methods of ZnO-TiO2 and its application have been reviewed as well as the factors that affect the morphology, performance, and the stability of ZnO-TiO2 nanocomposite. This review is conducted by comparing the analysis results with their performances. It is clearly found that there is an optimum condition for obtaining the best photocatalytic performance by adjusting the ratio of ZnO to TiO2. Furthermore, ratio of ZnO:TiO2 concentration on antimicrobial activity shows a linear performance, and it is obviously observed that the ZnO- TiO2 nanocomposite shows a better performance compared to the pristine ZnO or TiO2 in various applications. We believe that this review will provide valuable information and new insights into possible fabrication methods of ZnO-TiO2 nanocomposite materials, which can be used in many applications.