第一作者:张恒睿
通讯作者:邢璇
通讯单位:中央民族大学
DOI:10.1016/j.cej.2024.156427
为提高电化学体系中H2O2的原位生成性能,本研究制备了一种硼(B)改性空气扩散电极(B@ADE)。将B掺杂的炭黑(CB)沉积在ADE表面作为催化层。研究了不同B/C质量比下B@ADE的性能,其中0.3为最优质量比,45 min时0.3-B@ADE体系的H2O2产量可达204.85 mg L-1,为ADE的1.51倍。同时,验证了H2O2在B@ADE表面的自催化作用,并分析了不同操作参数对·OH形成的影响。XPS分析表明,BC2O、BC2O和C=O/O-C=O与H2O2的生成有关。DFT计算结果表明,BCO2有利于O2的吸附,而BC2O则利于*OOH的解吸,降低自由能垒,促进H2O2和·OH的生成。淬灭实验表明,OH、O2·-和1O2在体系中共存,同时对各物种的贡献进行了量化。通过DFT计算的活性位点鉴定和HPLC-MS/MS的中间体检测,提出了四种可能的降解途径。生物毒性分析结果表明,大多数中间体的毒性均低于CIP。这些结果表明, B@ADE电化学氧化体系增强了H2O2的原位生成和自催化,具有巨大的实际应用潜力。
Fig. 1. Scheme of x-B@ADE preparation.
Fig. 2. (a) Degradation of CIP, (b) H2O2 yield and (c) current efficiency in EAOP system with x-B@ADE. (d) Water contact angels and (e) digital photos of x-B@ADE and CF.
Fig. 3. TEM and HRTEM images of CB (a,c) and 0.3B-CB (b,d). Element mapping (e-h) and ToF-SIMS image (i) of 0.3B-CB.
Fig. 4. N2 adsorption–desorption isotherm (a), the pore size distribution curve (b), Raman spectrum(c), and EIS (d) of 0.3B-CB and CB.
Fig. 5. CV test of 0.3B-CB and CB in O2 (a) and N2 (b) atmosphere. LSV (c) and electron transfer number (d) of 0.3B-CB and CB.
Fig. 6. Self-activation of 0.3-B@ADE. The effect of current density on ·OH concentration (a-b) and H2O2 yield (c) within 15 min (c). The effect of pH values on ·OH concentration (d-e) and H2O2 yield (f) within 15 min.
Fig. 7. B 1 s (a), C 1 s (b), O 1 s (c) spectra and corresponding content of different O (d), B (e) and C groups (f) for x-B@ADE with x from 0.1 to 2
Fig. 8. O 1 s (a), B 1 s (b), C 1 s (c) spectra of used 0.3-B@ADE and content of O (d), B (e) and C groups (f) for fresh and used 0.3-B@ADE.
Fig. 9. Configuration O2 adsorption on (a) BC2O and (b) BCO2. Configuration of *OOH generation on (c) BC2O and (d) BCO2. Free energy diagram H2O2 generation and activation on BC2O (e) and BCO2 (f).
Fig. 10. (a) The effect of pH on CIP degradation. Quench experiment at pH of (b) 3, (c) 5.9 (c), (d) 9 and (e) 11. (f) The contribution of different ROS at different pH.
B@ADE双功能阴极应用于EAOP体系,促进了H2O2的原位生成和自催化。在不同的B/C质量比中,0.3-B@ADE在45 min内的H2O2产量最高(204.85 mg L-1),而普通碳毡(CF)浸没在水中时H2O2产量仅为10.69 mg L-1。DFT计算表明,BCO2有利于O2吸附,BC2O有利于*OOH生成H2O2和·OH,XPS分析结果也证实了这一点。pH对H2O2原位生成和自催化的影响研究表明,酸性条件有利于H2O2和·OH的生成。在pH为3-9的范围内,OH和O2·-为主导ROS,而pH为11时, 1O2起重要作用。提出了CIP的4种降解途径,并分析了中间体的毒性。本研究提出了一种无金属改性阴极EAOP体系的设计思路及其降解抗生素的潜力。
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