Synthesis of Pd nanoparticles decorated with graphene and their application in electrocatalytic degradation of 4-chlorophenol

• Published in: Journal of nanoscience and nanotechnology Vol. 14; no. 9; p. 7279
• Main Authors: Bian, Zhao-Yong, Bian, Yu, Wang, Hui, Ding, Ai-Zhong
• Format: Journal Article
• Language: English
• Published: United States 01.09.2014
• Subjects: Chlorophenols - analysis; Chlorophenols - chemistry; Electrochemical Techniques - methods; Graphite - chemistry; Metal Nanoparticles - chemistry; Palladium - chemistry
• ISSN: 1533-4880
• DOI: 10.1166/jnn.2014.8949

Pd/graphene catalysts were prepared in situ from graphite oxide and palladium salts by the hydrogen-reduction method and were then used for the construction of Pd/graphene gas-diffusion electrodes (GDE). The prepared catalysts were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and differential pulse voltammetry (DPV) techniques. In the Pd/graphene catalysts, Pd particles, with an average size of 3.6 nm and an amorphous structure, were highly dispersed in the graphene. The Pd/graphene catalysts accelerated the two-electron reduction of O2 to H2O2 by feeding air, which favors the production of hydroxyl radicals (HO*). In the electrolytic system, HO* was determined in the reaction mixture by the electron spin resonance spectrum (ESR). The dechlorination degree of 4-chlorophenol reached approximately 90.5% after 80 min, and the removal efficiency and the average removal efficiency of 4-chlorophenol, in terms of total organic carbon (TOC) after 120 min, reached approximately 93.3% and 85.1%, respectively. Furthermore, based on the analysis of electrolysis intermediates by high performance liquid chromatography (HPLC) and ion chromatography (IC), a reaction scheme was proposed for the Pd/grapheme GDE catalytic degradation of 4-chlorophenol.