Photoelectrocatalytic degradation of glyphosate on titanium dioxide synthesized by sol-gel/spin-coating on boron doped diamond (TiO2/BDD) as a photoanode
Photoelectrocatalytic degradation of glyphosate on titanium dioxide synthesized by sol-gel/spin-coating on boron doped diamond (TiO2/BDD) as a photoanode
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DOI：
10.1016/j.chemosphere.2021.130488
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发表时间：
2021-04-08
期刊：
影响因子：
8.8
通讯作者：
Espinoza-Montero, Patricio J.
中科院分区：
文献类型：
--
作者：
Alulema-Pullupaxi, Paulina;Fernandez, Lenys;Espinoza-Montero, Patricio J.
报道了以硫酸氧钛为前驱体，在掺硼金刚石-BDD（BDD）上制备TiO 2-TiO 2（TiO 2/BDD）光阳极，并将其应用于水溶液中草甘膦的光电降解。研究分为三个阶段：（1）采用溶胶-凝胶/旋涂法优化TiO 2前驱体的层数，以[Fe（CN）（6）]（3-/4-）体系对TiO 2/BDD电极进行了扫描电镜-SEM、能谱-EDX、X射线衍射-XRD、接触角和电化学响应等表征;（3）BDD电氧化和TiO 2/BDD光电催化降解草甘膦（50 mg L-1），在黑暗和紫外光条件下，在不同的电流密度下，反应5 h。通过高效液相色谱、总有机碳、化学需氧量和无机离子（NO3-、PO 43-和NH 4+）浓度等指标评价了草甘膦的降解和矿化情况。此外，通过HPLC定量氨甲基膦酸-AMPA作为降解中间体。采用5层TiO 2前驱体，在较低的接触角下，实现了对[Fe（CN）（6）]（3-/4-）氧化还原体系的更好光电催化，并比未改性的BDD更好地降解草甘膦。通过SEM和XRD证实了在BDD上形成了纳米TiO 2（14.79 +/- 3.43 nm）。此外，在3 mA cm（-2）和紫外光下，相对于BDD，TiO 2/BDD光电催化草甘膦降解和矿化快2.3倍。因此，相对于BDD上的电化学氧化，BDD上的TiO 2的存在增加了草甘膦降解的速率和效率。(C)2021爱思唯尔有限公司保留所有权利。
The construction of a photoanode with several layers of titanium oxysulfate as a precursor to form titanium dioxide-TiO2 on boron doped diamond-BDD (TiO2/BDD), and its application for the photoelectro-degradation of glyphosate in aqueous medium are presented. The study was divided into three stages: i) optimization of the number of layers of the TiO2 precursor to modify BDD using a novel method combining Sol-gel/Spin-Coating; ii) characterization of the TiO2/BDD electrodes, by scanning electron microscopy-SEM, dispersive energy spectroscopy-EDX, Ray diffraction-XRD, contact angle, and electrochemical response by cyclic voltammetry using [Fe(CN)(6)](3-/4-) system; iii) degradation of glyphosate (50 mg L-1) by electrochemical oxidation on BDD and photoelectrocatalysis on TiO2/BDD in dark and UV-light conditions, at different current densities, for 5 h. The glyphosate degradation and mineralization were evaluated by High-Performance Liquid Chromatography, Total Organic Carbon, Chemical Oxygen Demand and inorganic-ions concentration (NO3-, PO43-, and NH4+). Also, the aminomethylphosphonic acid-AMPA was quantified by HPLC, as a degradation intermediate. Using five layers of the TiO2 precursor, in the construction of TiO2/BDD photoanode, and a lower contact angle, greater photoelectrocatalysis against the [Fe(CN)(6)](3-/4-) redox system and better degradation of glyphosate compared to BDD without modification were achieved. The formation of TiO2 nanoparticles (14.79 +/- 3.43 nm) in anatase phase on BDD was verified by SEM and XRD. Additionally, glyphosate degradation and mineralization were 2.3 times faster by photoelectrocatalysis on TiO2/BDD, relative to BDD, at 3 mA cm(-2) and UV-light. Thus, the presence of TiO2 on BDD increases the rate and efficiency of glyphosate degradation with respect to electrochemical oxidation on BDD. (C) 2021 Elsevier Ltd. All rights reserved.