| dc.description.abstract | With the development of industry, the issue of environmental pollution is becoming an increasingly important issue that cannot be ignored. Many people are devoted to the sustainable development of the environment, therefore, the reduction of pollutants generated by industrial development has become an important issue. Photocatalysts are often used in the degradation of environmental pollutants, because of its low cost and high efficiency, so the development of photocatalysts has attracted much attention. Titanium dioxide is the most popular photocatalyst material because of its non-toxic, stable, low cost, and abundant. Therefore, this study investigates the properties of titanium dioxide modification by first principle calculations with the purpose of titanium dioxide having a wider application.
In this study, we discussed three different structures, pristine TiO2(101), Cu5/TiO2(101), and Cu4Fe/TiO2(101), and investigated the electronic structure, methanol adsorption sites, and methanol dissociation mechanism of the three structures. The results of the calculations show that TiO2(101) adsorbed with metal clusters have a smaller band gap of 1.579 eV for Cu5/TiO2(101) and 1.527 eV for Cu4Fe/TiO2(101). This means that the application of modified TiO2(101) surface is no longer limited to ultraviolet light, but expands its application to the visible and infrared light environment. It is worth noting that the bimetallic cluster-modified TiO2(101) shows a better band gap reduction effect. In addition, the photocatalytic hydrogen production reaction of methanol is one of the popular applications of photocatalysts, so the dissociation mechanism of methanol is the main concern of our study to investigate whether the TiO2(101) modification by adsorption of metal clusters has the effect of reducing the energy barrier of methanol dissociation reaction. In this study, all the possible methanol adsorption sites on TiO2(101) were tested and the most stable methanol adsorption configurations on the three structures were determined by geometry optimization calculations. Then, the dissociation mechanism of methanol on the three different structures was calculated. The dissociation mechanism of methanol is divided into two steps. Although TiO2(101) modified by metal clusters has a slightly higher energy barrier in the second step, the energy barrier in the first step has a smaller effect on Cu4Fe/TiO2(101), which facilitates the dissociation reaction of methanol. | en_US |