SEPARATION AND PURIFICATION TECHNOLOGY
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2022
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IF 9.136
Jiandong Guo,Aiqin Zhang,Zhen Pei,Xuguang Liu,Bingshe Xu,Husheng Jia
Photo-Fenton performance of Fe-based metal–organic frameworks needs to be further improved owing to little coordinatively unsaturated metal sites (Lewis acid sites) and poor photogenerated carrier separation and migration efficiency. In view of this problem, this work has developed missing-linker metal–organic framework with mix-valence coordinatively unsaturated metal site (abbreviated as CUS-Pac-MIL-100 (Fe)) for photo-Fenton degradation by thermal activation and introducing missing linker. The structure of catalysts was characterized by SEM, XRD, XPS, in-situ DRIFT, TG, BET, and EPR, which proves abundant mixed-valence coordinatively unsaturated metal sites are introduced by vacuum thermal activation and plenty of ligand vacancies are introduced by missing-linker. The conditions for TC-HCl degradation were optimized. The results indicate that CUS-Pac-MIL-100 (Fe) exhibits remarkable removal rate of TC-HCl within 80 min at 10 mL/L H 2 O 2 dosage, 0.2 g/L catalyst dosage, and a wide pH range (4.0–7.0). The total organic carbon (TOC) removal rate also reaches 52.3% within 80 min. Such remarkable improvement in the photo-Fenton activity is attributed to the mix-valence coordinatively unsaturated metal sites improving the adsorption and activation ability of H 2 O 2 , and the ligand vacancies promoting the separation efficiency of carriers to accelerate Fe 2+ regeneration. The catalyst also exhibits excellent cyclability and stability after multiple cycles. Further, the degradation mechanism and degradation pathways of TC-HCl in the photo-Fenton reaction has been proposed on the basis of radical quenching, electron paramagnetic resonance, and LC-MS tests. This work provides a worthy insight for the construction of high-efficiency MOF-based photo-Fenton materials.
研究领域:
环境科学
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材料科学
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产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2021
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IF 7.312
Jiandong Guo,Husheng Jia,Aiqin Zhang,Zhen Pei,Man Luo,Jinbo Xue,Qianqian Shen,Xuguang Liu,Bingshe Xu
Iron-based MOFs have been considered as the candidate for Fenton-like reagents owing to their open pore size and uniformly dispersed Fe active centers. However, the strong coordination of metal ions with organic ligands greatly reduces the exposed active sites of most iron-based MOFs, thus reducing Lewis acid sites and limiting the activation efficiency of H 2 O 2 . At the same time, low Fe 3+ /Fe 2+ cycle efficiency also restricts H 2 O 2 activation efficiency. Hence, in this work, a series of MIL-100 (Fe) containing mixed valence coordinatively unsaturated metal site (CUS) with different Fe 2+ /Fe 3+ ratios was synthesized by heat treatment and used for tetracycline hydrochloride (TC-HCL) degradation with the assistance of visible light. Interestingly, accelerated Fe 3+ /Fe 2+ cycle was observed with the aid of visible light. Among the prepared samples, CUS-MIL-250 prepared under vacuum at 250℃ has superior degradation performance, primarily owing to its large specific surface area and pore volume, improved visible light absorption, and the introduction of more Fe 2+ CUS. Meanwhile, compared with Fenton-like system and photocatalytic system, the CUS-MIL-250/H 2 O 2 /Vis system, with effective separation of photogenerated electrons and holes, demonstrates a synergistic effect to generate more reactive oxidation species, thereby improving the degradation efficiency. In addition, the catalyst shows good stability and recyclability.
研究领域:
环境科学
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材料科学
✓ 已验证
DOI
高影响因子
BIOSENSORS & BIOELECTRONICS
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2023
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IF 12.6
Jun Wang,Jiawen Han,Juan Wang,Xujuan Lv,Daoqing Fan,Shaojun Dong
Versatile nanozymes with fascinating catalytic properties provide inspiring and effective options for biosensing and pharmaceutical analysis. Herein, we report the first nanozyme-based ratiometric fluorescent platform for cysteine (Cys) and bleomycin (BLM) detection by harnessing the cost-effective and “mix & act” G-quadruplex/Cu(II) (G4/Cu) metal-nanozyme with satisfactory peroxidase-like activity, which was fully proven by circular dichroism (CD), electron paramagnetic resonance (EPR) spectra and reactive oxygen species (ROS) scavenging experiments. Based on the catalytic oxidation of G4/Cu metal-nanozyme toward two fluorescent substrates (Amplex Ultrared, AU; Scopoletin , Sc) with opposite responses in the presence of H 2 O 2 , and the specific interaction between Cu 2+ and targets, we achieved the highly sensitive detection of Cys and BLM. Through recording the fluorescence changes of AU (emission at 590 nm, F590) and Sc (emission at 465 nm, F465), we obtained good linear relationships between ratiometric fluorescence values (F590/F465) and variable contents of targets, resulting in the competitive LODs of Cys (6.7 nM) and BLM (10 nM), respectively. Moreover, this platform presented high selectivity (without the need for masking agent) and acceptable performance in human serum samples. Furthermore, a library of DNA contrary logic pairs (CLPs) and multilevel concatenated circuits were fabricated based on the reverse dual-output of the above platform, enriching the building blocks of biocomputing. This work not only enlightened the design of affordable, “mix & act” type nanozyme-based ratiometric biosensors with high reliability, but also facilitated the pluralistic application of nucleic acid-templated nanozymes to innovative biocomputing.
研究领域:
生物传感
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药物分析
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生物计算
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产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）