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

Abstract

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 K 4 [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.

Algorithm for Assessing the Convergence of a Cyclic Voltammetry to Its Limit Cycle

“…However, in the decades of the 60s and the 70s, significant advances were made in the theory and the instrumentation of voltammetric methods, such as the development of low-cost operational amplifiers that enabled affordable potentiostats. 2 These advances boosted the practical applicability of voltammetric methods, leading to the actual situation where voltammetric methods are widely used in a large variety of fields, such as electrodeposition, 3 batteries, [4][5][6][7] fuel cells, 8,9 supercapacitors, 10,11 electrochemical advanced oxidation, [12][13][14] electrochemical sensors, [15][16][17][18] ionic liquids [19][20][21][22] and surfactants, 23 amongst many others.…”