Synthesis and Photocatalytic Application of Magnetic CoFe₂O₄/Conjugated Poly(vinyl chloride) Derivative Nanocomposite

Abstract

CoFe 2 O 4 has potential for application as a magnetically recoverable visible-light photocatalyst, but its photocatalytic activity is encumbered by the high recombination probability of its photogenerated holes (h + ) and electrons (e − ). This work was undertaken to boost the photocatalysis of CoFe 2 O 4 through coupling with conjugated poly(vinyl chloride) derivative (CPVC). An easily implementable solvothermal−liquid solid mixing−evaporation of the solvent−pyrolysis method was exploited to synthesize CoFe 2 O 4 /CPVC nanocomposites. The photocatalytic capabilities of the products were assessed through photocatalyzing the reduction of Cr(VI) under visible-light (λ > 420 nm). The results demonstrate that the optimal CoFe 2 O 4 /CPVC nanocomposite (CoFe 2 O 4 /CPVC-2) has markedly heightened photocatalytic activity (3.6 times that of CoFe 2 O 4 ) and competent reusability and is magnetically recoverable. Furthermore, CoFe 2 O 4 /CPVC-2 also shows superior performance toward photocatalytic treatment of the diluted Cr(VI)-containing passivation solution of copper alloys. It is deduced based on the photoelectricity measurement results that the increased photocatalysis of CoFe 2 O 4 /CPVC-2 is chiefly attributed to its p−n heterojunction structure, which greatly elevates the h + −e − separation and transfer efficiency. When waste PVC plastic films (replacing the new pure PVC powder) were utilized for the synthesis, the obtained CoFe 2 O 4 /CPVC nanocomposite exhibited even better photocatalytic activity (4 times that of CoFe 2 O 4 ). This work not only has made a new magnetically recoverable, efficient visible-light photocatalyst for decontamination of Cr(VI) in water but also is inspirational for recycling PVC plastic waste to produce high-valued visible-light photocatalysts.