Electrochemical Oxidation of Atrazine and Clothianidin on Bi-doped SnO₂–Ti_nO_2n–1 Electrocatalytic Reactive Electrochemical Membranes

Abstract

This research focused on improving mineralization rates during the advanced electrochemical oxidation treatment of agricultural water contaminants. For the first time, bismuth-doped tin oxide (BDTO) catalysts were deposited on Magneĺi phase (Ti n O 2n−1 , n = 4−6) reactive electrochemical membranes (REMs). Terephthalic acid (TA) was used as a OH • probe, whereas atrazine (ATZ) and clothianidin (CDN) were chosen as model agricultural water contaminants. The BDTO-deposited REMs (REM/BDTO) showed higher compound removal than the REM, due to enhanced OH • production. At 3.5 V/SHE, complete mineralization of TA, ATZ, and CDN was achieved for the REM/BDTO upon a single pass in the reactor (residence time ∼3.6 s). Energy consumption for REM/BDTO was as much as 31-fold lower than the REM, with minimal values per log removal of <0.53 kWh m −3 for TA (3.5 V/SHE), <0.42 kWh m −3 for ATZ (3.0 V/SHE), and 0.83 kWh m −3 for CDN (3.0 V/ SHE). Density functional theory simulations provided potential dependent activation energy profiles for ATZ, CDN, and various oxidation products. Efficient mass transfer and a reaction mechanism involving direct electron transfer and reaction with OH • were responsible for the rapid and complete mineralization of ATZ and CDN at very short residence times.

Recent advances in electrocatalysts for halogenated organic pollutant degradation

“…In this process, water moves through the pores on the designed electrode materials, which can minimize the thickness of the boundary layer, thus significantly upgrading the mass transfer rate of HOPs moving towards the electrode surface. 226,227,239 In a recent work, tubular porous Ti/SnO 2 -Sb filters which possessed excellent electrochemical activity and penetration flux were worked as anodic reactive electrochemical membranes in a reactive electrochemical filter system. 227 The developed reactive electrochemical filter system in flow-through mode resulted in a higher RhB oxidation efficiency than the flow-by mode by 8.6-fold under the same operational conditions.…”

Rapid and selective electrochemical transformation of ammonia to N2 by substoichiometric TiO2-based electrochemical system

“…An increased ow rate (e.g., 4 mL min À1 ) also facilitates the rapid sweeping out of bubbles. 24,25 Therefore, 3.0 V vs. Ag/AgCl was selected as optimal for subsequent investigations.…”

Membrane processes

“…The performance of bismuth‐doped tin oxide (BDTO) catalyst deposited on the Mangneli phase (Ti n O 2 n ‐1 , n = 4–6) reactive electrochemical membranes (REMs) was the subject of study by Gayen, Chen, Chen, Abiade, and Chaplin (2018). Using terephthalic acid (TA) as OH* probe and atrazine (ATZ) and clothianidin (CDN) used as model agricultural water contaminants, the researchers reported the BDTO‐deposited REMs (REM/BDTO) showed higher compound removal than REM, due to the enhanced OH* production.…”