Photovoltammetry of p-Phenylenediamine Mediated by Hexacyanoferrate Immobilized on CdS-Graphene Nanocomposites

Redox active hexacyanoferrate (HCF) was immobilized on CdS-graphene (CdS-G) electrode to study the photovoltammetric behavior of p-phenylenediamine (PPD). Under visible light illumination, the immobilized HCF could quickly consume photogenerated carriers on CdS-G electrode and mediate the photoelectrocatalytic oxidation of PPD, leading to an enhanced anodic limiting current response. The HCF/CdS-G electrode fabricated with 1% graphene content in CdS-G composites and 0.3 mmol·L−1 K4[Fe(CN)6] was found to show the optimum photovoltammetric response to PPD. The fabricated HCF/CdS-G electrode was explored for photovoltammetric determination of PPD, which showed a current response linearly proportional to PPD concentration from 1.0 × 10−7 to 1.0 × 10−5 mol·L−1. The detection limit (3S/N) was 4.7 × 10−8 mol·L−1. Moreover, the HCF/CdS-G electrode displayed good reproducibility and high stability. The developed photovoltammetric method was successfully applied to the determination of PPD in environmental water samples.