Synthesis, characterisation and photocatalytic properties of visible light responsive Co2Co4(SiW10O37)2/Fe2O3 composites.

Co₂Co₄(SiW₁₀O₃₇)₂/Fe₂O₃ composite photocatalysts were created by chemical synthesis. FTIR, UV–Vis, XRD, and SEM were used to characterise the materials. The result demonstrates that polyoxometalates have a massive structure and that ferric oxide is tightly coupled with polyoxometalates in the composites. By varying the pH and amount of Fe₂O₃, the optimal synthesis conditions for the composites were determined. The catalytic degradation of methyl orange solution was performed in the presence of a xenon lamp (18.085 mW/cm²). When the pH was set to one, the composite had the best decomposition effect on methyl orange, with a decomposition efficiency of 76.2%. Simultaneously, the possible mechanism of the photocatalytic process was investigated. The photocatalytic process was almost completely inhibited after the photogenerated holes were masked by triethanolamine. The results indicate that photogenerated holes are the deciding factor in the composites' photocatalytic effect. They also measured the composites' band gap width with UV–Vis spectroscopy and cyclic-voltammetry, and the likely photocatalytic mechanism was thoroughly investigated. [ABSTRACT FROM AUTHOR]