Catalytic Electrogenerated Chemiluminescence and Nitrate Reduction at CdS Nanotubes Modified Glassy Carbon Electrode

• Published in: Langmuir 2009-01, Vol.25 (1), p.555-560
• Main Authors: Fang, Yi-Min, Sun, Jian-Jun, Wu, Ai-Hong, Su, Xiu-Li, Chen, Guo-Nan
• Format: Article
• Language: English
• Subjects: Cadmium Compounds - chemistry; Carbon - chemistry; Catalysis; Chemiluminescence; Chemistry; Colloidal state and disperse state; Electrochemistry: Charge Transfer, Electrocatalysis, Kinetics, Bioelectrochemistry; Electrodes; Exact sciences and technology; General and physical chemistry; Glass; Luminescence; Nanotubes; Nitrates - chemistry; Oxidation-Reduction; Sulfides - chemistry; Surface physical chemistry; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry
• ISSN: 0743-7463; 1520-5827
• DOI: 10.1021/la802650e

Electrochemical and electrogenerated chemiluminescence (ECL) properties of a glassy carbon electrode modified with CdS nanotubes (CdS−GCE) are investigated in neutral media. The cyclic voltammogram (CV) shows two cathodic peaks (PC1 and PC2) at −0.76 and −0.97 V and an anodic peak (PA) at −0.8 V, while two ECL peaks around −0.76 V are observed. Similar mechanisms of both ECLs are supposed and possibly related to the capture of an electron at a surface trap, that is, the surface sulfide vacancy (VS 2+) of CdS nanotubes and its electrocatalytic reduction to H2O2 generated from the dissolved oxygen. PC2 and PA are ascribed to the two-electron redox at VS 2+. Moreover, electrocatalysis to nitrate reduction is also found at PC2, with a good linear relationship between nitrate concentration and electrocatalytic peak current in CV.