Electrospun TiO 2 /carbon composite nanofibers as effective (photo)electrodes for removal and transformation of recalcitrant water contaminants
Electrospun TiO 2 /carbon composite nanofibers as effective (photo)electrodes for removal and transformation of recalcitrant water contaminants
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电纺 TiO 2 /碳复合纳米纤维作为有效（光）电极去除和转化顽固水污染物
DOI：
10.1039/d3va00017f
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发表时间：
2023
期刊：
影响因子：
--
通讯作者：
Mubeen, Syed
中科院分区：
文献类型：
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作者：
Butzlaff, Ashley Hesterberg;Jensen, Madeline;Yan, Chenxu;Ghanim, Abdulsattar;Werth, Charles;Cwiertny, David;Mubeen, Syed
电化学（EC）和光电化学（PEC）水处理系统越来越受欢迎，需要在各种应用平台上提供可靠性能的新型电极材料。对于专门针对稀释化学污染物（即百万分之一浓度或更低）的应用，有益的电极性能包括高表面积，以克服动力学过电位损失，低电极面积电阻，高透水性，具有足够的机械强度，可用于电活性膜基处理系统。在这里，我们使用静电纺丝技术从含有二氧化钛（TiO2）纳米粒子的碳纳米纤维（CNFs）中制造（光）电极。最佳的CNF/TiO2复合材料具有电化学和光化学活性，其表面积为~ 50 m2 g−1，电极面积电阻为2.66 Ω cm2，与商业碳基电极材料（例如Kynol活性炭布）相当。对顽固性有机污染物卡马西平（CBZ）的转化实验表明，CNF/TiO2电极具有双重吸附剂功能，首先结合CBZ，然后在正电位下氧化。在EC（暗）和PEC（紫外线；280 mW cm - 2）体系中，在90分钟内观察到完全的CBZ转化，PEC体系在+1.00 V（相对于Ag/AgCl）下的转化率高1.5倍（kobs ~ 0.18 min - 1）。复合电极在重复使用中也表现出稳定性，在CBZ转换的五个实验周期（每个120分钟）中产生一致的电流密度（0.25±0.03 mA cm - 2）。由于其高表面积、导电性、光活性和电化学稳定性，这些电纺丝CNF/TiO2复合材料代表了各种EC和PEC应用的有前途的（光）电极替代品。
Electrochemical (EC) and photoelectrochemical (PEC) water treatment systems are gaining popularity, necessitating new electrode materials that offer reliable performance across diverse application platforms. For applications specifically targeting dilute chemical pollutants (i.e., parts-per-million concentrations or less), beneficial electrode properties include high surface area to overcome kinetic overpotential losses, low electrode areal electrical resistance, and high water permeability with sufficient mechanical strength for use in electroactive membrane-based treatment systems. Here, we used electrospinning to fabricate (photo)electrodes from carbon nanofibers (CNFs) containing titanium dioxide (TiO2) nanoparticles. Optimal CNF/TiO2 composites were electrochemically and photochemically active with a surface area of ∼50 m2 g−1 and electrode areal resistance of 2.66 Ω cm2, values comparable to commercial carbon-based electrode materials (e.g., Kynol Activated Carbon Cloth). Transformation experiments with carbamazepine (CBZ), a recalcitrant organic contaminant, suggest CNF/TiO2 electrodes function dually as sorbents, first binding CBZ prior to oxidation at positive applied potentials. Complete CBZ transformation was observed in both EC (dark) and PEC (UV light; 280 mW cm−2) systems over 90 minutes, with PEC systems exhibiting 1.5-fold higher transformation rates (kobs ∼ 0.18 min−1) at +1.00 V (vs. Ag/AgCl). Composite electrodes also exhibited stability across repeated use, yielding consistent current densities over five experimental cycles (120 min each) of CBZ transformation (0.25 ± 0.03 mA cm−2). Because of their high surface area, electrical conductivity, photoactivity, and electrochemical stability, these electrospun CNF/TiO2 composites represent promising (photo)electrode alternatives for diverse EC and PEC applications.