Fabrication, characterization and electrocatalytic properties of a solid modified electrode based on PW11O39Fe(III)(H2O)4− and chitosan

Highlights: ► A novel solid modified electrode PW11Fe/CS/C was fabricated by sol–gel process. ► The electrode shows an excellent eletrocatalytic activity towards H2O2 reduction. ► An efficient eletrocatalytic degradation of nitrobenzene by the electrode was obtained. - Abstract: A solid modified electrode based on PW11O39Fe(III)(H2O)4− (PW11Fe) and chitosan (CS) was fabricated by sol–gel process via immobilization of PW11Fe, adsorbed on CS, onto the surface of a glassy carbon (GC) or a graphite (C) electrode with methyltrimethoxysilane as a cross-linking agent. After characterization by scanning electron microscope (SEM) and transmission electron microscope (TEM), the electrochemical characteristics of the PW11Fe/CS/C system and its electrocatalytic activity towards H2O2 reduction were investigated using electrochemical methods such as cyclic voltammetry and alternating current impedance. It was found that the PW11Fe/CS/C system still retained the electrochemical properties of the PW11Fe and its eletrocatalytic activity towards H2O2 reduction in homogeneous solution. Application of the PW11Fe/CS/C system in electrocatalytic degradation of nitrobenzene (NB) revealed that 100% of NB degradation was obtained at 120 min in 0.1 M Na2SO4 + NaHSO4 (pH 3.5) solution containing 1 mM NB.