Preparation of Graphite-UiO-66(Zr)/Ti electrode for efficient electrochemical oxidation of tetracycline in water

Abstract

Tetracycline (TC) is widely-used antibiotic pollutant with high toxicity, refractory, persistence and bacteriostasis, and its removal from water needs to be enhanced. In this work, a novel Graphite-UiO-66(Zr)/Ti electrode was successfully prepared and evaluated for electrochemical oxidation degradation of TC. The electrochemical performance tests indicate the Graphite-UiO-66(Zr)/Ti electrode had higher electrochemical oxidation activity, which achieved higher TC removal efficiency (98.1% ± 1.5%) than Ti plate (65.2% ± 3.5%), Graphite-MIL-53(Al)/Ti electrode (79.5% ± 2.9%) and Graphite-MIL-100(Fe)/Ti electrode (89.0% ± 2.6%). The influence of operating condition was also systematically studied, and the optimized condition was pH 5.0, 20 mA/cm2 current density and 0.1 M electrolyte (Na2SO4). Through the liquid chromatography mass spectrometry (LC-MS), the TC degradation pathway by Graphite-UiO-66(Zr)/Ti electrode oxidation was proposed. Under the •OH free radical oxidative decomposition effect, the double bond, phenolic group and amine group of TC were attacked. TC was transformed into intermediate product ① (m/z = 447), then was further degraded to intermediates ② (m/z = 401) and ③ (m/z = 417). The latter was fragmented into small fractions ④ (m/z = 194), ⑤but-2-enedioic acid (m/z = 116) and ⑥oxalic acid (m/z = 90, the proposed intermediate). In addition, TC removal remained at 89.6% ± 2.7% in the sixth cycle of operation, which confirmed the efficient reusability and stability for antibiotics removal from water.

Molecular inspired electrocatalyst materials for environmental remediation

“…The stability of the UiO-66 electrode was measured over 6 cycles showing a decrease in activity of 8.5%. 151 The FE of single atom nickel coordinated with nitrogen (Ni-N 4 ) for CO is 99% at −0.81 V vs. SHE. 152 Similarly, other types of Ni incorporated into N-doped carbon based materials, such as N-doped carbon black, Ni-nitrogenated graphene 153 and Ni-hollow carbon nanospheres, 154 show close to 99% FE for CO production at potentials ranging from −0.6 to −0.8 vs. SHE.…”

“…The stability of the UiO-66 electrode was measured over 6 cycles showing a decrease in activity of 8.5%. 151…”

Simultaneous Analysis of Trace Tetracyclines Antibiotics in Wastewater with Ultra-high Performance Liquid Chromatography Coupled with Mass Spectrometry

“…In recent years, many methods have been proposed to eliminate tetracycline in water environment [7], such as electrochemical oxidation [8], microbial degradation [9], photocatalytic method [10], adsorption method [11,12], advanced oxidation process [13] and so on [14,15]. Despite of above researches, the real application of these techniques is limited.…”