Article

The degradation of microcystin-LR using doped visible light absorbing photocatalysts.

Innovation, Design and Sustainability Research Institute (IDeaS), The Robert Gordon University, Schoolhill, Aberdeen, UK.
Chemosphere (Impact Factor: 3.5). 02/2010; 78(9):1182-5. DOI: 10.1016/j.chemosphere.2009.12.003
Source: PubMed

ABSTRACT Microcystins are one of the primary hepatotoxic cyanotoxins released from cyanobacteria. The presence of these compounds in water has resulted in the death of both humans and domestic and wild animals. Although microcystins are chemically stable titanium dioxide photocatalysis has proven to be an effective process for the removal of these compounds in water. One problem with this process is that it requires UV light and therefore in order to develop effective commercial reactor units that could be powered by solar light it is necessary to utilize a photocatalyst that is active with visible light. In this paper we report on the application of four visible light absorbing photocatalysts for the destruction of microcystin-LR in water. The rhodium doped material proved to be the most effective material followed by a carbon-modified titania. The commercially available materials were both relatively poor photocatalysts under visible radiation while the platinum doped catalyst also displayed a limited activity for toxin destruction.

0 Followers
 · 
200 Views
  • [Show abstract] [Hide abstract]
    ABSTRACT: Innovative sol–gel synthesis based on the self-assembling template method has been applied to synthesize mesoporous anion-doped TiO2 with N–F, S and C atoms using suitable surfactants and reagents, to improve simultaneously the structural, morphological, and electronic properties of TiO2 nanomaterials and achieve anion doping of titania with high visible light photoinduced reactivity. The incorporation of anion species in the titania structure resulted in the effective extension of TiO2 optical absorption in the visible range through the formation of intragap energy states. The anion-doped titania materials immobilized in the form of nanostructured thin films on glass substrates exhibited high photocatalytic efficiency for the degradation of the microcystin-LR (MC-LR) cyanotoxin, a hazardous water pollutant of emerging concern, under visible light irradiation. The development of these visible light-activated nanocatalysts has the potential of providing environmentally benign routes for water treatment.
    Industrial & Engineering Chemistry Research 02/2013; 52(39):13957–13964. DOI:10.1021/ie3034575 · 2.24 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Microcystins, which are a group of hepatotoxins, have stable physicochemical properties. Photocatalysis has been proven to be effective for removing refractory organics. In this study, a novel visible light-sensitive photocatalyst (Ag/Ag3PO4), prepared by a simple irradiation method was used to treat microcystins (MC-LR, -YR, -RR). Results indicated that MC-LR was more easily degraded by Ag/Ag3PO4 catalysts than by Ag3PO4 alone, which was attributed to the change of Ag3PO4 morphology and the deposition of Ag nanoparticles (NPs) on Ag3PO4 after irradiation treatment. The photocatalytic efficiency of Ag/Ag3PO4 was found to be affected by both catalyst dosage and light intensity. The oxidation of the microcystins over this heterojunction catalyst reacted differently, with the removal efficiency following the trend: MC. YR > MC-RR > MC-LR. It is also worth noticing that the ratio of Ag NPs to Ag3PO4 for the best photocatalytic activity of the Ag/Ag3PO4 heterojunction in degrading MC-LR was not the one for the most stable state of it.
    Chemical Engineering Journal 08/2013; 230:172-179. DOI:10.1016/j.cej.2013.06.076 · 4.06 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Photocatalytic water treatment using nanocrystalline titanium dioxide (NTO) is a well-known advanced oxidation process (AOP) for environmental remediation. With the in situ generation of electron-hole pairs upon irradiation with light, NTO can mineralize a wide range of organic compounds into harmless end products such as carbon dioxide, water, and inorganic ions. Photocatalytic degradation kinetics of pollutants by NTO is a topic of debate and the mostly reporting Langmuir-Hinshelwood kinetics must accompanied with proper experimental evidences. Different NTO morphologies or surface treatments on NTO can increase the photocatalytic efficiency in degradation reactions. Wisely designed photocatalytic reactors can decrease energy consumption or can avoid post-separation stages in photocatalytic water treatment processes. Doping NTO with metals or non-metals can reduce the band gap of the doped catalyst, enabling light absorption in the visible region. Coupling NTO photocatalysis with other water-treatment technologies can be more beneficial, especially in large-scale treatments. This review describes recent developments in the field of photocatalytic water treatment using NTO.
    12/2012; 2(4):572-601. DOI:10.3390/catal2040572

Full-text (2 Sources)

Download
11 Downloads
Available from
Sep 4, 2014