The Effect of Transition Metal Doping on the Photooxidation Process of Titania‐Clay Composites

Abstract

Montmorillonite- composites containing various transition metal ions (silver, copper, or nickel) were prepared, and their photocatalytic efficiencies were tested in the degradation of ethanol vapor at 70% relative humidity. Two light sources, UV-rich ( = 254 nm) and visible ( = 435 nm), were used. The kinetics of degradation was monitored by gas chromatography. It was established that, in the case of each catalyst, ethanol degradation was more efficient in UV-C ( = 254 nm) than in visible light, furthermore, these samples containing silver or copper ions were in each case about twice more efficient than P25 (Degussa AG.) used as a reference. In photooxidation by visible light, /clay samples doped with silver or copper were also more efficient than the reference sample, P25 . We show that doping metal ions can also be delivered to the surface of the support by ion exchange and significantly alters the optical characteristics of the /clay composite.

Thermal, structural and ethylene adsorption properties of Ag-, Cu- and Fe-modified bentonite from Turkey

“…1, the impurities such as illite, quartz and feldspar remained in the Ag-B, Cu-B and Fe-B samples. Menesi et al[47] also observed the similar changes after treatment of smectite with silver, copper and iron nitrate solutions.…”

“…This shows that copper ions can be incorporated between the silicate layers and produce well-oriented lamellar structure[47]. In addition, Ag-B, Cu-B and Fe-B samples showed a decrease in the intensities of the other reflections of montmorillonite (4.48 and 2.57 Å ), indicating the compositional change within the bentonite after the exchange of heavy metals and a loss of crystallinity of the smectite.…”

Decontamination of Chemical Warfare Agents – What is Thorough?

“…Chemically, clays are hydrous aluminum silicates, ordinarily containing impurities, for example, potassium, sodium, calcium, magnesium, or iron in small amounts [33]. Every soldier should be well educated in terms and methods of hasty decontamination.…”

Photooxidation of ethanol on Cu-layer silicate/TiO2 composite thin films

“…The Na-ions were exchanged with copper nitrate (1 mmol g -1 clay). The compositions of the catalysts prepared for thin film of ~1 µm thickness were the following: 20/80, 35/65, 50/50, 75/25 Cu-clay/TiO 2 ratio [26].…”

“…700 ml) at 25 ± 0.1°C. The experimental setup and schematic drawing of the photoreactor are described in our previous papers [26,27]. The light sources of the reactor were two types of 15 W low pressure mercury lamp (LightTech, Hungary), at λ max = 254 nm and λ max = 435 nm wavelength.…”