Phosphomolybdic acid immobilized on graphite as an environmental photoelectrocatalyst

Chemosphere. 2016 Oct:161:422-428. doi: 10.1016/j.chemosphere.2016.07.030. Epub 2016 Jul 22.

Abstract

A new phosphomolybdic acid (PMA)/Graphite surface was prepared based on electrostatic interactions between phosphomolybdic acid and graphite surface. The PMA/Graphite was characterized by cyclic voltammetry (CV) analysis and scanning electron microscope (SEM). SEM images showed that the phosphomolybdic acid particles were well stabilized on the graphite surface and they were evidenced the size of particles (approximately 10 nm). The CV results not only showed that the modified surface has good electrochemical activity toward the removal of the dyestuff, but also exhibits long term stability. The PMA/Graphite was used as a photoanode for decolorization of Reactive Yellow 39 by photoelectrocatalytic system under UV irradiation. The effects of parameters such as the amount of phosphomolybdic acid used in preparation of PMA/Graphite surface, applied potential on anode electrode and solution pH were studied by response surface methodology. The optimum conditions were obtained as follows: dye solution pH 3, 1.5 g of immobilized PMA on graphite surface and applied potential on anode electrode 1 V. Under optimum conditions after 90 min of reaction time, the decolorization efficiency was 95%.

Keywords: Dyestuff; Electrostatic interaction; Environment; Photoelectrocatalyst; Polyoxometalate.

MeSH terms

  • Catalysis
  • Coloring Agents / chemistry
  • Electrochemical Techniques
  • Electrodes
  • Graphite / chemistry*
  • Graphite / radiation effects
  • Microscopy, Electron, Scanning
  • Molybdenum / chemistry*
  • Molybdenum / radiation effects
  • Phosphoric Acids / chemistry*
  • Phosphoric Acids / radiation effects
  • Ultraviolet Rays

Substances

  • Coloring Agents
  • Phosphoric Acids
  • Graphite
  • Molybdenum
  • phosphomolybdic acid