Preparation of photocatalysts of TiO2 and Ag-TiO2 was carried out by coprecipitation method. The prepared photocatalysts were characterized by X-ray diffraction (XRD), SEM, EDX, and XRF analysis. The disinfection of
Increasing demand and shortage of satisfactory clean water supplies due to the rapid development of industrialization, population growth, and serious droughts have become a global issue [
Heterogeneous photocatalysis has recently emerged as an alternative technology of advanced oxidation processes (AOP) for bacteria inactivation [
The aim of this work was the preparation of TiO2 and Ag doped TiO2 (Ag-TiO2) by the simple coprecipitation method. The prepared photocatalysts were characterized by X-ray diffraction (XRD), SEM, EDX, and XRF analysis. The photocatalytic inactivation and disinfection of
All chemicals used such as Ti(SO)2, urea, or silver nitrate were of reagent grade (SHOWA Chemical Co., LTD., Japan or Ruenn-Jye Tech. Corp., Taiwan). The photocatalytic antibacterial activities of the samples were evaluated using
For the preparation of Ag-TiO2 powder, 75 g of urea was first dissolved into 400 mL DI-water. Then add 46 mL of Ti(SO4)2 and 0.169 g of AgNO3 into the bottle on the oil bath and uniformly mixed. Reactions were carried out for 24 h at 80°C by continuously magnetic stirring and heating. After cooling to room temperature, the separation of solid and solution was obtained by centrifugal filtration. The solids were washed by DI-water until pH of the washing water reached neutral. The solids were filtered again and removed to the oven for drying at 70°C and 24 h. By grinding, the powder was then calcined at 550°C for 4 h. The Ag-TiO2 was obtained with Ag : Ti = 1 : 99 (molar ratio). To prepare TiO2, the same procedure was repeated without the addition of silver nitrate.
Structure characterization of as prepared photocatalysts was performed by means of XRD (XRD-6000, Shimadzu, Japan) with Cu K
The antibacterial properties of
The inactivation efficiency
Ag-TiO2 after 550°C sintering was characterized by the SEM. The micrographs taken at 6000-times magnification are shown in Figure
SEM micrograph of Ag-TiO2 sintering at 550°C (×6.0k).
XRD pattern of prepared TiO2 and Ag-TiO2 with different sintering temperature.
EDX of Ag-TiO2 sintering at 550°C.
The compositions of the prepared Ag-TiO2 were determined by the analysis of XRF. The result was shown in Table
XRF of prepared Ag-TiO2.
Components | Conc.: mol% | STD-DEV | Intens.: cps/ |
---|---|---|---|
Ti (titanium) | 97.83 | 0.08 | 138.140 |
V (vanadium) | 1.2 | 0.07 | 2.533 |
Ag (silver) | 0.81 | 0.03 | 3.575 |
Fe (iron) | 0.16 | 0.03 | 0.248 |
Figures
Inactivation effect of
According to the kinetic Langmuir-Hinshelwood model [
By the linear transform of
Figure
Figures
Values of
TiO2 |
|
|
Ag-TiO2 |
|
|
---|---|---|---|---|---|
Dark | 19% | 0.03 | Dark | 19.46% | 0.03 |
Visible | 23% | 0.28 | Visible | 23.14% | 0.28 |
Dark + TiO2 | 87% | 0.7 | UV | 100% | 1.67 |
Visible + TiO2 | 96% | 1.08 | Dark + Ag-TiO2 | 100% | 6.56 |
UV | 99% | 1.56 | Visible + Ag-TiO2 | 100% | 6.67 |
UV+TiO2 | 100% | 2.22 | UV + Ag-TiO2 | 100% | 6.67 |
Inactivation effect of
In order to study the mineralization of
TOC removal percentage of
TOC removal percentage of
TOC removal percentage of
Photocatalysts of TiO2 and Ag-TiO2 were successfully prepared by coprecipitation method annealed at 550°C; the composition of Ag-TiO2 prepared is about Ag : Ti = 1 : 99 (molar), and particle size is 0.25 silver-deposited TiO2 photocatalysts enhanced the inactivation of the study of mineralization of the visible light may effectively be applied for the disinfection unit of water and wastewater treatment system by using photocatalysts of Ag-TiO2.