ACS Applied Polymer Materials
·
2023
·
IF 5
Siyuan Zhang,Jiao He,Xinjian Cheng
Amphiphilic hyperbranched polymers (AHBPs) possess important characteristics, such as high solubility, low viscosity, and multiple functional groups, making them of significant scientific interest. In this work, a chain transfer agent (CTA) with a styrene unit was synthesized at first. Subsequently, the CTA was polymerized with a coumarin derivative containing a −C=C bond through reversible addition-fragmentation chain transfer-self-condensing vinyl polymerization (RAFT-SCVP) to obtain the hyperbranched polymer HP-1. Finally, using HP-1 as a macromolecular CTA, amphiphilic hyperbranched fluorescent probes AHP-2 and AHP-3 were synthesized via RAFT polymerization of hydrophilic monomers poly[oligo(ethylene glycol) methacrylate] (PEGMA) and 2-(dimethylamino)ethyl methacrylate (DMAEMA). The as-prepared AHP-2 and AHP-3 were characterized and confirmed. These macromolecular fluorescent probes enable highly sensitive and specific recognition of 4-nitrophenol (4-NP) with detection limit as 0.59 μM. A unique fluorescence quenching effect, termed “enriching inner filter effect (IFE)”, was revealed through the study of the recognition mechanism of the probes for 4-NP in hyperbranched polymers. This effect has the potential to expand the preparation methods of both fluorescent probes and functional hyperbranched polymers. This work investigates the synthesis methodology of amphiphilic hyperbranched polymers and the performance of fluorescent probes, providing a valuable approach for the development of highly sensitive polymer fluorescent probes in the future.
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CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Fengliang Cao,Qingshan Zhao,Debin Kong,Xiaojie Tan,Xinxin Li,Tengfei Liu,Linjie Zhi,Mingbo Wu
Atomically dispersed metal-nitrogen-carbon (M-N-C) catalysts show great potential for heterogeneous catalysis. However, recognizing and engineering the microenvironment of M-N x sites to achieve satisfactory catalytic performance remains challenging. Herein, we propose a facile g-C 3 N 4 -assisted template strategy to anchor atomic Fe-N 4 sites on highly nitrogen-doped carbon nanosheets. Through regulating the ratio and type of peripheral nitrogen species by carbonization temperature, the optimal Fe-N-C-800 catalyst showed significantly boosted catalytic activities (overall turnover frequency of 13.43 min −1 and activation energy of 19.44 kJ mol −1 ) for nitroarene reduction with extremely low reductant dosage, exceeding most reported metal catalysts. Experimental and theoretical results reveal appropriate graphitic- and pyrrolic-N dopants surrounding the Fe-N 4 center can tailor the local electronic structure and contribute to obvious upshift of the d-band center, which dramatically promotes the adsorption and conversion of reactant substrates, eventually delivering the unprecedented catalytic performance. This work provides a guide for rational coordination environment regulation of single-atom catalysts for efficient chemical transformations.
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CHEMICAL ENGINEERING SCIENCE
·
2023
·
IF 4.7
Guoqiang Guo,Qi Zheng,Tingting Li,Ting Zhang,Siyuan Tang,Lintao Li,Sineng Gao,Yan Tang,Da Chen
For facile and rapid detection of 4-nitrophenol (4-NP), we synthesize nitrogen-doped carbon dots (N-CDs) through microwave radiation treatment using melamine and o-phenylenediamine as precursors. We employed N-CDs as an ingenious ratiometric fluorescence sensor via a novel bimodal excitation behavior. As the concentration of N-CDs increases, the broad excitation peak splits into two excitation peaks. The blue-shift phenomenon appears at the short-wavelength excitation peak, while the long-wavelength excitation peak presents the red-shift. Consequently, 4-NP can be sensitively detected by N-CDs owing to the localization of inner filter effect (L-IFE) with the detection limit of 83 nM ranging from 0.083 to 80 µM. Moreover, a self-calibrating on-site sensing platform constructed by 3D printing technique realizes the visual 4-NP detection in actual samples based on bimodal excitation behavior and RGB analysis. Our work not only presents a novel perspective for visual 4-NP sensing, but also renders the integration of 3D printing technology and the CDs industry.
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FOOD CHEMISTRY
·
2023
·
IF 8.8
Guoqiang Guo,Tingting Li,Ziyi Liu,Xinyu Luo,Ting Zhang,Siyuan Tang,Xu Wang,Da Chen
Recently, converting bio-waste into bio-asset and implementing a portable sensing instrument for pollutant monitoring has been highly desirable and challenging. Herein, biomass-derived nitrogen-doped carbon dots (CDs) are prepared hydrothermally and emit blue fluorescence (470 nm) with a high quantum yield of 23.2%. Significantly, CDs can serve as a pH-modulated fluorescence switching nano-sensor to detect 4-NP from 0.054 to 68 μM with low detection limit (LOD, 54 nM) and limit of quantification (LOQ, 181 nM) based on inner filter effect. Moreover, the satisfactory recovery of 101.8–107.5% is gained in practical sample monitoring. Furthermore, a smartphone-integrated optosensing device with CDs-based film is developed for detecting 4-NP with LOD and LOQ of 0.110 μM and 0.350 μM. Concomitantly, the practicability of this device is further validated in several crop samples with satisfactory recovery rates of 101.6–108.6%. Therefore, this work provides a reliable way and a prospective application for on-site 4-NP monitoring in food.
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JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS
·
2023
·
IF 4
Baogang Su,Yao Li,Yijun Du,Linjun Shao,Hongyu Tao,Chenze Qi,Shujing Zhou,Jinjing Li
Supported transition metal catalysts have played a critical role in the modern synthetic chemical industry. Herein, MCM-41 was chemically modified with amino groups and then used as the support of six transition metal cations . The chemical structures , microstructures and dispersions of these supported transition metal cations were carefully characterized by XRD , TEM and BET. The chelations of modified MCM-41 support with these transition metal cations were confirmed by FT-IR and XPS . The reduction reaction of 4-nitrophenol into 4-aminophenol was employed to evaluate the catalytic activities and recyclabilities of these supported transition metal catalysts. Meanwhile, their reactivities with o -Ps species were assessed by positron annihilation lifetime spectroscopy (PALS). It was found that the reduced o -Ps annihilation intensities (ΔI 3 ) were well associated with their catalytic activities while the o -Ps annihilation lifetime values (τ 3 ) were related to their catalytic recyclabilities. In all, the catalytic activities and recyclabilities of supported transition metal cations can be conveniently evaluated by their o -Ps annihilation properties. This method holds great potential in the design and preparation of highly active and stable supported transition metal catalysts.
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LANGMUIR
·
2023
·
IF 3.9
Xiaoyu Li,Yuanyuan Min,Feng Liu,Maochang Liu,Yiqun Zheng
Frame/skeleton-like nanostructures are of great value in plasmonic catalysis as a result of the synergetic structural advantages arising from both maximized surface atomic exposure and efficient incident light absorptions. Herein, we report the size-tunable fabrication of yolk–shell AuAg nanoparticles containing a spherical core and cuboctahedral skeletons (AuAg YSCNSs), together with the exploration of their applications for assisting the reduction of 4-nitrophenol (4-NP) under ultraviolet–visible (UV–vis) light irradiation. The use of glutathione (GSH) at an appropriate amount to mediate the galvanic replacement reaction between Au@Ag core–shell nanocubes and HAuCl4 is found to be crucial in regulating the shape evolution. Their sizes could be readily tuned by altering the edge lengths of Au@Ag core–shell nanocubes. When working as the photocatalyst assisting the reduction of 4-NP, the AuAg YSCNSs exhibit a higher apparent rate constant under UV–vis light irradiation. The current work demonstrates the feasibility to create skeleton-like noble metal nanocrystals with the shape largely deviated from that of the original template via the “top-down” carving strategy by introducing non-metallic surface doping, which could be potentially extended to other noble metals or alloys.
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ACS Applied Polymer Materials
·
2023
·
IF 5
Xiaoqiu Yao,Runxin Teng,Ming Jin,Decheng Wan
Uniform gold nanoclusters (AuNCs) are hardly available unless through abundant strong ligands (at the cost of low catalytic activity and narrow catalytic spectrum) or through well-defined (but expensive) templates, and it appears a tougher challenge for direct preparing supported and uniform AuNCs. Here, we show that with an amphiphilic and dendritic molecular template in hand, highly catalytically active, uniform, and supported AuNCs are one-pot achievable. Branched polyethylenimine (PEI) is modified with a few thioether groups and alkylated with hydrophobic acetyls and polystyrene chains to afford reverse micelle-like dendritic polymers. The structurally optimized dendritic polymer can act as a surfactant to mediate very stable water-in-oil high internal phase emulsion (HIPE) within a wide pH spectrum. Moreover, the dendritic polymer switches into the unimolecular state along the interface of the HIPE when pH is below 6, which is critical to the formation of uniform AuNCs. Experimentally, upon the transformation of HIPE into an open-cellular polyHIPE, the gold ions are simultaneously transformed into AuNCs. Direct preparation of the supported and uniform AuNCs (1.8 ± 0.2 nm) are feasible because the dendritic polymer can simultaneously act as a surfactant, a polymer ligand, and a unimolecular template. Meanwhile, the trace thioether groups in the PEI core reduce the size of AuNCs by enhancing nucleation of AuNCs since in the absence of thioether groups, larger particles are obtained. The supported AuNCs are catalytically active because they are stabilized by weak coligands. For the model reaction of the catalyzed reduction of 4-nitrophenol, the catalyst shows a turnover frequency of 112.5 h–1, which is very high. The catalyst is durable and well recyclable.
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RSC Advances
·
2023
·Vol. 13
·期 37
·25828-25835
·
IF 3.9
Xia Xu,Liming Yang,Yanjun Cui,Bing Hu
The successful development of efficient and stable catalysts for 4-NP reduction reactions is beneficial to the environment and ecology. Fe3O4@Pt exhibits excellent catalytic performance for 4-NP reduction reaction due to the synergistic effect between Fe and Pt. But its structure and catalytic performance are extremely unstable. Here, we utilized the small-scale organic compound 2-hydroxyethylamine as surfactant to construct a stable composite nanomaterial. Then investigated the influence of monochromatic light (650 nm, 808 nm and 980 nm) and temperature on the kinetics of 4-NP reduction reaction by 2-hydroxyethylamine stabilized Fe3O4@Pt. The results indicate that both temperature and monochromatic light radiation can affect kinetic regulation. Increasing temperature can promote the catalytic rate, while monochromatic light radiation can induce agglomeration and inhibit the catalytic rate. This study opens up a new way for developing and regulating catalysts for heterogeneous catalysis reactions.
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WATER AIR AND SOIL POLLUTION
·
2023
·Vol. 234
·期 7
·1-17
·
IF 2.9
Xiao Sihua,Wan Jinquan,Wang Yan,Yan Zhicheng,Ma Yongwen,Sun Jian,Tang Min,Cao Jianye,Chen Jinxin
The large-scale wastewater treatment plants (WWTPs) in developed regions collect volumes of wastewater containing various emerging contaminants (ECs) every day, but without any effective process to eliminate them. Therefore, it is of vital importance to study the occurrence of ECs in the effluents from WWTPs. In this study, the concentration levels and pollution characteristics of typical ECs in effluents were investigated for source identification and risk assessment. In total, 13 of 39 analyzed ECs were detected in the effluents, with the highest detection concentration at 706 µg/L (oxolinic acid). Sulfaphenazole showed the highest detection frequency at 100%, while Liede WWTP (1.2 million m 3 /day), located at Tianhe District, was with the highest detection concentration (899 µg/L) among all sampling sites. Parallel factor analysis was applied to identify the dissolved organic matters (DOMs) of excitation–emission matrix spectroscopy (EEMS) first. Based on previous research data, the connection between DOMs and pollution sources could be built. Then, principal component analysis (PCA) and Pearson’s correlation analysis were used to determine the correlation between ECs and DOMs. Finally, ecological and health risk quotients were calculated for the risk assessment of ECs. The results illustrated that oxolinic acid, sulfaphenazole, sulfaquinoxaline, sulfadimethoxypyrimidine, penicillin V, and flumequine were potentially discharged from human activities and livestock, poultry, and aquaculture industry; the possible sources of sulfadoxine and nafcillin were agricultural activities, food production, and catering industry; sulfapyridine and erythromycin were believed to come from hospital wastewater; and the discharges of lincomycin, sulfameter, and sulfamerazine were related to petrochemical industry or chemical production activities. Except for sulfadoxine, all detected ECs posed a high or median risk on aquatic ecosystem, which is enough to threaten aquatic organisms. Even though only oxolinic acid, sulfaquinoxaline, and sulfadimethoxypyrimidine presented a potential risk on humans’ health, the cumulative effect of ECs in the human body still needs attention. The threats of ECs from large-scale WWTPs in China’s developed regions are pointed out for the first time, which could possibly bring widespread attention on emerging pollution from WWTP effluents, potentially advance the introduction of relevant policies, and provide the direction and target pollutants for follow-up mitigation actions.
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TALANTA
·
2023
·
IF 6.1
Haoyu Long,Yanhao Jiang,Yanjuan Liu,Yuefei Zhang,Wei Chen,Sheng Tang
In this work, 2,4,6-tris(4-aminophenyl)-1,3,5-triazine (TAPT) and 1,3,5-tris(4-formylphenyl)benzene (TFPB) were used as monomers to construct a triazine-containing imine-linked covalent organic framework (COF), which was then bonded onto the surface of aldehydized silica (SiO 2 –CHO), and finally a COF@silica composite material (TAPT-TFPB COF@SiO 2 ) was successfully prepared. The chromatographic separation performance of SiO 2 –CHO, TAPT-TFPB COF@SiO 2 and TAPT-TFPB COF@SiO 2 /SiO 2 –CHO (80/20, mass ratio) was evaluated and compared. It was found that separation efficiency was obviously enhanced by adding an appropriate amount of SiO 2 –CHO into TAPT-TFPB COF@SiO 2 . The obtained TAPT-TFPB COF@SiO 2 /SiO 2 –CHO showed more favorable separation ability than SiO 2 –CHO and TAPT-TFPB COF@SiO 2 . Various aromatic compounds including alkylbenzenes , polycyclic aromatic hydrocarbons , environmental endocrine disruptors , foodborne stimulants and phenyl ketones were effectively separated on the TAPT-TFPB COF@SiO 2 /SiO 2 –CHO column in reversed phase chromatography mode. The silica microspheres surface-modified with triazine-containing imine-linked COFs proved to be a new type of promising chromatographic packing materials.
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FOOD AND CHEMICAL TOXICOLOGY
·
2023
·
IF 4.3
Huiying Huang,Jian Shi,Zhongyi Li,Yifeng Rang,Weiye Li,Xueman Xiao,Congying Chen,Chunhong Liu
Nonylphenol (NP) exposure can trigger neurotoxicity and cause learning and memory impairment. Nicotinamide mononucleotide (NMN) has a therapeutic effect on neurodegenerative diseases , but the role of NMN on NP-induced learning and memory impairment is not known. Here, we examined the mitigative effect of NMN on the impaired learning and memory ability of rats exposed to NP. The NP impaired learning and memory in rats, while the low-dose intervention with NMN significantly prolonged the step-through latency of the PAT and improved the NAMPT and NMNAT1 content in brain tissue. At the same time, the NMN intervention also increased the content of 5-HTR 1A , 5-HTR 4 , and 5-HTR 6 related to learning and memory in the hippocampus. In line with this, we found that the NMN intervention activated the SIRT1/MAO-A pathway in brain tissue. NMN intervention, especially at 125 mg/kg doses, may improve rats’ NP-induced learning and memory impairment via the central 5-HT system and the NAD + /SIRT1/MAO-A pathway in the brain.
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Small Structures
·
2023
·Vol. 4
·期 10
·2300137
·
IF 15.9
Jingpeng Li,Rumin Ma,Sisi Yao,Daochun Qin,Yun Lu,Yuhe Chen,Zehui Jiang,Dongjiang Yang
Plant-based flow microreactors with natural channel structures, renewable properties, and environmental friendliness have increasingly gained popularity in heterogeneous catalysis. However, firmly immobilizing the catalysts simultaneously with ease and adaptability, maintaining great effectivity and long-term stability, is still a fundamental challenge. Herein, a highly efficient and ultrastable bamboo-based catalytic microreactor (CMR) containing mesoporous TiO 2 (M-TiO 2 )-encapsulating ultrafine Pd nanoparticles (NPs) is constructed for the continuous-flow hydrogenation of nitroaromatics. The fabrication of the Pd-TiO 2 catalysts in required bamboo microchannels (Pd-TiO 2 /B CMR) mainly involves a two-step region-selective synthetic strategy with ultra-low chemical usage, fast preparation, and low catalyst loading (0.007 wt%). The M-TiO 2 films: 1) provide abundant oxygen vacancies and enough open cavities to facilitate the growth of Pd NPs; 2) improve Pd dispersion and reduce particle size; 3) allow diffusion of reactants, and 4) induce strong metal-support interactions for enhanced catalytic activity and stability. The optimized Pd-TiO 2 /B CMR demonstrates high efficiency (>97%) and excellent stability (1,000 h) for the continuous-flow hydrogenation of nitroaniline, even under intermittent operation (12 h on/12 h off for five cycles) or in a real aqueous matrix (>200 h), making it a promising candidate for Pd-catalyzed hydrogenation.
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