Influence of parameters on the heterogeneous photocatalytic degradation of pesticides and phenolic contaminants in wastewater: A short review

TiO2 photocatalyst for water treatment applications

In this review, for a variety of metals and semiconductors, an attempt is made to generalize observations in the literature on the effect of process conditions applied during photodeposition on (i) particle size distributions, (ii) oxidation states of the metals obtained, and (iii) consequences for photocatalytic activities. Process parameters include presence or absence of (organic) sacrificial agents, applied pH, presence or absence of an air/inert atmosphere, metal precursor type and concentration, and temperature. Most intensively reviewed are studies concerning (i) TiO2; (ii) ZnO, focusing on Ag deposition; (iii) WO3, with a strong emphasis on the photodeposition of Pt; and (iv) CdS, again with a focus on deposition of Pt. Furthermore, a detailed overview is given of achievements in structure-directed photodeposition, which could ultimately be employed to obtain highly effective photocatalytic materials. Finally, we provide suggestions for improvements in description of the photodeposition methods applied when included in scientific papers.

Methods, Mechanism, and Applications of Photodeposition in Photocatalysis: A Review.

Photocatalytic oxidation of organic dyes and pollutants in wastewater using different modified titanium dioxides: A comparative review

1 A Practical Introduction to Differential Scanning Calorimetry. 2 Fast Scanning DSC. 3 ThermoGravimetric Analysis. 4 Principles and applications of mechanical thermal analysis. 5 Applications of thermal analysis in electrical cable manufacture. 6 Application to Thermoplastics and Rubbers. 7 Thermal Analysis of Biomaterials. 8 Pharmaceuticals. 9 Thermal methods in the study of foods and food ingredients. 10 Thermal analysis of inorganic compound glasses and glass-ceramics

Principles and applications of thermal analysis

The photooxidation of oxalic acid, catalyzed by nanosized TiO2 or WO3 and composite photocatalysts: Au/TiO2, Au/WO3, WO3/TiO2, Au/WO3/TiO2 was studied under irradiation with UV, visible and combined UV–visible light. The catalysts were characterized by the XRD, XPS, SEM and TEM methods. The photocatalytic mineralization of oxalic acid, catalyzed by WO3/TiO2 or Au/WO3/TiO2, proceeded at a significantly higher rate under UV-A irradiation than that under visible light. This is due to the lower specific surface area of the WO3 and its small amount in the composite catalyst. Doping of the semiconductor materials with gold nanoparticles more than doubles the rates of mineralization of oxalic acid, compared to the un-doped samples, and more significantly in the case of Au/WO3/TiO2. The higher rate constants of oxalic acid decomposition under UV, visible or UV–visible light irradiation with the WO3/TiO2 and Au/WO3/TiO2 catalysts, compared with those measured with the individual oxide photocatalysts, are due to the more efficient separation of the electron–hole charges generated upon irradiation. Especially efficient is the charge separation in the case of the Au/WO3/TiO2 photocatalyst under irradiation with UV or combined UV–visible light, when the rate constants of oxalic acid destruction are approximately 1.7 times higher than that of the process catalyzed by Au/TiO2 and 3 times higher than that catalyzed by pure TiO2.

Slavcho Rakovsky

Papers

Enhancement of photocatalytic oxidation of oxalic acid by gold modified WO3/TiO2 photocatalysts under UV and visible light irradiation

Ozone decomposition on Ag/SiO2 and Ag/clinoptilolite catalysts at ambient temperature.

Nanosized N-doped TiO2 and gold modified semiconductors — photocatalysts for combined UV–visible light destruction of oxalic acid in aqueous solution

Kinetics and Mechanism of Ozone Reactions With Organic and Polymeric Compounds in Liquid Phase

Promoting the oxidative removal rate of oxalic acid on gold-doped CeO2/TiO2 photocatalysts under UV and visible light irradiation