The effect of the sp3/sp2 carbon ratio on the electrochemical oxidation of 2, 4-D with p-Si BDD anodes. (1st January 2016)

• Record Type: Journal Article
• Authors: Souza, F.L.; Saéz, C.; Lanza, M.R.V.; Cañizares, P.; Rodrigo, M.A.
• Is Part Of: Electrochimica acta. Volume 187(2016)
• Page Start: 119
• Page End: 124
• Publication Date: 2016-01-01
• Subjects: Boron-doped diamond -- sp3/sp2 ratio -- electrolysis -- pesticide -- 2-4-D -- perchlorate; Electrochemistry -- Periodicals; Electrochemistry, Industrial -- Periodicals; 541.37
• DOI: 10.1016/j.electacta.2015.11.031
• Languages: English
• ISSNs: 0013-4686

Abstract

Highlights: The efficiency of the electrolysis of 2, 4-D depends on the sp 3 /sp 2 ratio of the diamond anode. A higher sp 3 /sp 2 ratio lowers the energy required to mineralize the pesticide. The sp 3 /sp 2 ratio influences the concentration but not the type of intermediates produced. Chlorate and perchlorate production is favored at higher sp 3 /sp 2 ratios. Abstract: Boron-doped diamond films on silicon substrates (p-Si BDD) with different sp 3 /sp 2 carbon ratios are systematically varied in electrodes used to oxidize 2, 4-dichlorophenoxyacetic acid (2, 4-D) in synthetic wastewater containing chlorides. 2, 4-D is completely mineralized during the electrolysis. A higher sp 3 /sp 2 ratio in the anode results in a more rapid and efficient oxidative removal of 2, 4-D. Chlorinated compounds such as 4-chlororesorcinol, 2-chlorophenol, and 2, 4-dichlorophenol form as intermediates during the oxidative treatment. Although these compounds are completely depleted during the electrolysis, their maximum observed concentrations decrease as the sp 3 content increases in the anode. On the contrary, higher maximum concentrations are observed for non-chlorinated intermediates, especially hydroquinone, and there is a greater formation of chlorates and perchlorates in chloride-containing solutions as the sp 3 content increases in the anode.