PLoS One
·
2018
·Vol. 13
·期 4
·e0192324
·
IF 2.766
Hai-qian Zhao,Zhong-hua Wang,Xing-cun Gao,Cheng-hao Liu,Han-bing Qi
H 2 O 2 was adopted to oxidize NO in simulated flue gas at 100–500°C. The effects of the H 2 O 2 evaporation conditions, gas temperature, initial NO concentration, H 2 O 2 concentration, and H 2 O 2 :NO molar ratio on the oxidation efficiency of NO were investigated. The reason for the narrow NO oxidation temperature range near 500°C was determined. The NO oxidation products were analyzed. The removal of NO x using NaOH solution at a moderate oxidation ratio was studied. It was proven that rapid evaporation of the H 2 O 2 solution was critical to increase the NO oxidation efficiency and broaden the oxidation temperature range. the NO oxidation efficiency was above 50% at 300–500°C by contacting the outlet of the syringe needle and the stainless-steel gas pipe together to spread H 2 O 2 solution into a thin film on the surface of the stainless-steel gas pipe, which greatly accelerated the evaporation of H 2 O 2 . The NO oxidation efficiency and the NO oxidation rate increased with increasing initial NO concentration. This method was more effective for the oxidation of NO at high concentrations. H 2 O 2 solution with a concentration higher than 15% was more efficient in oxidizing NO. High temperatures decreased the influence of the H 2 O 2 concentration on the NO oxidation efficiency. The oxidation efficiency of NO increased with an increase in the H 2 O 2 :NO molar ratio, but the ratio of H 2 O 2 to oxidized NO decreased. Over 80% of the NO oxidation product was NO 2 , which indicated that the oxidation ratio of NO did not need to be very high. An 86.7% NO removal efficiency was obtained at an oxidation ratio of only 53.8% when combined with alkali absorption.
研究领域:
环境科学
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化学工程
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产品关联
DOI
PubMed
高影响因子
CRYSTENGCOMM
·
2017
·Vol. 20
·期 5
·679-688
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IF 3.474
Huihui Chen,Mei Yang,Sha Tao,Guangwen Chen
A facile, template-free and easily scalable approach has been developed for the preparation of Co3O4 nanorings, which can be divided into two stages: (1) formation of CoOOH nanorings and (2) high-temperature calcination of CoOOH nanorings in air. The key step for the synthesis of Co3O4 nanorings is the formation of CoOOH nanorings, prepared by the oxidation of β-Co(OH)2 nanoplates with H2O2 under strong basic conditions. The plausible growth mechanism governing the formation of CoOOH nanorings was correlated with Ostwald ripening. It was found that the dosage of H2O2 played a vital role in the formation of CoOOH nanorings. To a large extent, other experimental variables including the H2O2 concentration, Co2+ concentration, the molar ratio of Co2+ to OH− and the reaction temperature did not affect the preparation of the CoOOH nanorings. Furthermore, the as-prepared Co3O4 nanorings exhibited superior activity in comparison with Co3O4 nanoplates and commercial Co3O4 towards the catalytic decomposition of H2O2. The apparent rate constant of the as-prepared Co3O4 nanorings was 0.38 min−1, which is 2.2 times the value of Co3O4 nanoplates.
研究领域:
材料科学
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催化化学
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DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2020
·Vol. 44
·期 21
·8952-8959
·
IF 3.288
Hehe Qin,Jinhong Fan,Shun Mao
The Fenton method is an important water treatment process. However, the mechanism of the Fenton reaction is still not widely recognized. In this article, the autocatalysis process responsible for the degradation of 4-chlorophenol (4-CP) as well as the generation of Fe(II) and the decomposition of H2O2 is elaborated using a Fe(III)/H2O2 system. It was found that the one electron reduction of Fe(III) to Fe(II) via oxidization of H2O2 to ˙HO2 is not spontaneous according to the standard electrode potential rather than being limited by the rate constant of 0.0027 M−1 s−1 in view of the Haber–Weiss circulation. However, the reaction of Fe(III) and 4-CP is spontaneous with a second-order kinetic rate constant of >0.12 M−1 s−1 and a conversion rate of 0.56%, which triggers the switch of the Fenton-like reaction as a real rate-determining step. The circulation of Fe(III) to Fe(II) in the proposed Fenton-like reaction mechanism depends on the organic species and various intermediates, which indicates its reaction selectivity, preferable for organics with a stronger thermodynamic and kinetic activity. Besides, a slight pH decline with time-scale and the stoichiometric ratio of ˙OH to H2O2 and H2O2 to 4-CP being 1 and 2, respectively, pointed to the new proposed reaction mechanism. The discovery of the new reaction mechanism might promote the theoretical and technical advancement of the Fenton-like process.
研究领域:
环境科学
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化学工程
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DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2021
·
IF 10.588
Xiao Zhang,Bin Ren,Xi Li,Biming Liu,Shiwen Wang,Peng Yu,Yanhua Xu,Guoqiang Jiang
Carbon-bridge-modified malonamide (MLD)/g-C 3 N 4 (CN) was prepared by copolymerization of MLD with urea and melamine and loaded with Fe 3 O 4 for the high-efficiency removal of tetracycline (TC) in water under photo-Fenton. The prepared catalysts were characterized by SEM, TEM , N 2 adsorption–desorption analysis, XPS, XRD, and FTIR, which proved that the modification method successfully introduced the C bridge into the carbon nitride molecular system and increased the structural defects of the catalyst. The Carbon-bridge-modified MLD/CN/Fe 3 O 4 also had good visible-light response and charge-separation and transport abilities in the photoelectrochemical test. Degradation results showed that the photo-Fenton degradation of TC reached 95.8%, and the mineralization rate was 55.7% within 80 min at 80 mM H 2 O 2 dosage, 0.5 g/L catalyst dosage, and near-neutral pH by 0.8MLD/CN/Fe 3 O 4 . Moreover, the oxidation products and mineralization pathways of TC were explored by LC-MS. Toxicity analysis indicated low environmental threat of the intermediates in TC mineralization. EPR analysis and H 2 O 2 decomposition efficiency analyses showed an improvement in the H 2 O 2 decomposition performance of 0.8MLD/CN/Fe 3 O 4 . This work could provide a valuable insight for the application of heterogeneous photo-Fenton technology in wastewater treatment .
研究领域:
环境科学
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化学工程
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材料科学
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水处理技术
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DOI
PubMed
高影响因子
CHEMOSPHERE
·
2020
·
IF 5.778
Fengxia Chen,Daojian Tang,Ya Wang,Tuo Li,Jiahai Ma
A novel catalyst which integrates heterogeneous and homogenous Fenton reactions is designed and fabricated by encapsulating 2,5-dihydroxy-1,4-benzoquinone (2,5-DBQ) in ECDP-Fe 3 O 4 , a composite of Fe 3 O 4 nanoparticles immobilized on a β-cyclodextrin polymer (ECDP) with ethylene diamine tetraacetic acid (EDTA) as cross-linking agent. The 2,5-DBQ@ECDP-Fe 3 O 4 has superior catalytic performance for 4-nitrophenol and 2,4-dichlorophenol degradation compared with control systems. Mechanism study revealed that although the initial active site is Fe 3 O 4 loaded on ECDP, the actually catalyst is the iron ions released from Fe 3 O 4 but confined within the composite. EDTA in β-cyclodextrin polymer can improve both the solubility and adsorption capacity to H 2 O 2 of Fe 3 O 4 . The quinone molecules 2,5-DBQ in the β-cyclodextrin cavity can accelerate Fe 3+ /Fe 2+ cycle adjacent to the cavity, thus in favor of the decomposition of H 2 O 2 into OH as main reactive oxidizing species. The current catalyst integrates the advantages of homogeneous and heterogeneous advanced oxidation processes and is promising in practical applications.
研究领域:
环境科学
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催化
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化学工程
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材料科学
✓ 已验证
DOI
高影响因子
ANALYTICAL CHEMISTRY
·
2023
·
IF 7.4
Weixiang Huang,Chunli Yang,Jiaxi Gao,Jingjing Ye,Ruo Yuan,Wenju Xu
Exploring the cooperative amplification of peroxidase-like metal nanocomposites and cycled hairpin assembly is intriguing for sensitive bioanalysis. Herein, we report the first design of a unique electrochemical biosensor based on mimicking Au@FeCo nanozymes and bicycled hairpin assembly (BHA) for synergistic signal amplification. By loading the enzyme-like FeCo alloy in Au nanoparticles (AuNPs), the as-synthesized Au@FeCo hybrids display great improvement of electronic conductivity and active surface area and excellent mimic catalase activity to H2O2 decomposition into •OH radicals. The immobilization of Au@FeCo in an electrode sensing interface is stabilized via the resulting electrodeposition in HAuCl4 while efficiently accelerating the electron transfer of electroactive ferrocene (Fc). Upon the immobilization of a helping hairpin (HH) via Au–S bonds, a specific DNA trigger (T*) is introduced to activate BHA operation through competitive strand displacement reactions among recognizing hairpin (RH), signaling hairpin (SH), and HH. T* and RH are rationally released to catalyze two cycles, in which the transient depletion of dsDNA intermediates rapidly drives the progressive hairpin assemblies to output more products SH·HH. Thus, the efficient amplification of Au@FeCo mimic catalase activity combined with BHA leads to a significantly increased current signal of Fc dependent on miRNA-21 analogous to T*, thereby directing the creation of a highly sensitive electrochemical biosensor having applicable potential in actual samples.
研究领域:
电化学
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纳米技术
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生物化学
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生物传感器
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催化
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产品关联
DOI
PubMed
高影响因子
CRYSTAL GROWTH & DESIGN
·
2016
·
IF 4.425
Ting He,Huiqiong Wu,Xiaojuan Wang,Qiguang Zang,Peng Xue,Rujuan Shen,Li Dang,Yi Zhang,Juan Xiang
A facile strategy was developed to fabricate structure controllable microcrystals of ferrocene-based metal–organic (Fc-Ala-BCB) materials through evaporation-induced self-assembly. Two distinctive microcrystals, microrods and microtubes had been achieved by tuning the solvents during the self-assemblies. X-ray diffraction analysis was conducted on single crystals to investigate the packing mode of Fc-Ala-BCB molecules, which indicated the two crystals with the hexagonal system. Inheriting the aromaticity and chirality of ferrocenyl and l-Ala, this organic molecule self-assembled into a single-helix structure through intermolecule hydrogen bonds and π–π stacking. Theoretical analysis and stimulated computations were carried out to compare the surface energies of certain planes. Among those microcrystals, the microrods exhibited a higher chemical activity in catalyzing the decomposition of H2O2, due to the high-density atomic steps and kinks on the high energy surfaces. However, the hollow hexagonal tubes displayed appropriate catalytic activity and novel maneuverability toward catalyzing H2O2. The O2 bubbles accumulated at the inner walls of the microtube were periodically released as individual bubbles, suggesting their potential application as a new kind of microengine (e.g., the microrotor).
研究领域:
材料科学
·
纳米技术
·
化学工程
·
催化
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2023
·
IF 9.5
Yue Zhou,Xiaohua Chen,Shaoqi Zhan,Qiang Wang,Feng Deng,Qingzhi Wu,Jian Peng
Fenton-like radical processes are widely utilized to explain catalytic mechanisms of peroxidase-like nanozymes, which exhibit remarkable catalytic activity, cost-effectiveness, and stability. However, there is still a need for a comprehensive understanding of the formation, stabilization, and transformation of such radicals. Herein, a copper formate-based nanozyme (Cuf-TMB) was fabricated via a pre-catalytic strategy under ambient conditions. The as-prepared nanozyme shows comparable catalytic activity (Km, 1.02 × 10–5 mM–1; Kcat, 3.09 × 10–2 s–1) and kinetics to those of natural peroxidase toward H2O2 decomposition. This is attributed to the feasible oxidation by *OH species via the *O intermediate, as indicated by density functional theory calculations. The key ·OH radicals were detected to be stable for over 52 days and can be released in a controlled manner during the catalytic process via in situ electron spin-resonance spectroscopy measurements. Based on the understanding, an ultrasensitive biosensing platform was constructed for the sensitive monitoring of biochemical indicators in clinic settings.
研究领域:
纳米技术
·
生物传感器
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催化
·
分析化学
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产品关联
DOI
PubMed
高影响因子
Science Advances
·
2024
·Vol. 10
·期 26
·
IF 11.7
Ruifeng Luo,Jinwei Liu,Qian Cheng,Mitsuhiko Shionoya,Cheng Gao,Ruibing Wang
Oral medication for ulcerative colitis (UC) is often hindered by challenges such as inadequate accumulation, limited penetration of mucus barriers, and the intricate task of mitigating excessive ROS and inflammatory cytokines. Here, we present a strategy involving sodium alginate microspheres (SAMs) incorporating M2 macrophage membrane (M2M)–coated Janus nanomotors (denominated as Motor@M2M) for targeted treatment of UC. SAM provides a protective barrier, ensuring that Motor@M2M withstands the harsh gastric milieu and exhibits controlled release. M2M enhances the targeting precision of nanomotors to inflammatory tissues and acts as a decoy for the neutralization of inflammatory cytokines. Catalytic decomposition of H2O2 by MnO2 in the oxidative microenvironment generates O2 bubbles, propelling Motor@M2M across the mucus barrier into inflamed colon tissues. Upon oral administration, Motor@M2M@SAM notably ameliorated UC severity, including inflammation mitigation, ROS scavenging, macrophage reprogramming, and restoration of the intestinal barrier and microbiota. Consequently, our investigation introduces a promising oral microsphere formulation of macrophage-biomimetic nanorobots, providing a promising approach for UC treatment.
研究领域:
药学
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纳米技术
·
胃肠病学
·
生物医学工程
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产品关联
DOI
PubMed
高影响因子
ANALYTICA CHIMICA ACTA
·
2022
·
IF 6.911
Hui Ouyang,Hongwei Yuan,Junyi Huang,Jiaxin Xian,Wenwen Wang,Zhifeng Fu
In view of the optimal catalytic efficiency (∼100%), single-atom site catalysts are being widely exploited in a range of areas including organic synthesis, energy conversion, environmental remediation, biotherapy, etc. However, low loading ratio of the unitary active sites on single-atom site catalysts dramatically hinders the remarkable improvement of their catalytic activity . Hereby, a facile low-temperature reduction protocol was adopted for synthesizing CoN 4 -supported Co 2 N metal clusters on graphitic carbon nitride , which show the remarkably superior chemiluminescent (CL) catalytic capacity than some reported pure single-atom site catalysts. Nitrogen-encapsulated Co 2 N clusters coupled with isolated Co–N 4 moieties (Co 2 [email protected] –N 4 ) endowed the synergetic catalysts with high Co content of 53.2 wt%. Through X-ray absorption spectroscopy, the synergetic active sites (Co 2 [email protected] –N 4 ) afforded the CoN 4 -supported Co 2 N clusters with the remarkable catalytic activity for accelerating the decomposition of H 2 O 2 to produce extensive superoxide radical anion rather than singlet oxygen or hydroxyl radical . Therefore, the CoN 4 -supported Co 2 N clusters possessed the superb enhancement effect on luminol-H 2 O 2 CL reaction by ∼22829 times. The CoN 4 -supported Co 2 N clusters were utilized as signal probes to establish a CL immunochromatographic assay (ICA) platform for quantitating mycotoxins . Herein, aflatoxin B1 was employed as a mode analyte and the limit of detection was as low as 0.33 pg mL −1 (3σ). As a proof-of-principle work, the developed ICA protocol was successfully employed on the detection of aflatoxin B1 spiked in Angelica dahurica and Ganoderma lucidum with acceptable recoveries of 84.0–107.0%. The ideal practicability of the work elucidates that CoN 4 -supported Co 2 N clusters showed a new perspective for developing the sensitive CL biosensing.
研究领域:
分析化学
·
材料科学
·
生物化学
·
食品安全
✓ 已验证
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）