Journal of Materials Chemistry B
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2020
·Vol. 8
·期 33
·7494-7500
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IF 5.344
Chan Song,Weiwen Zhao,Haibo Liu,Wei Ding,Linlin Zhang,Jie Wang,Yuewei Yao,Cheng Yao
In the past few years, the development of novel nanozymes with excellent performance has attracted increasing attention in biosensing. However, most of those nanozymes were found to possess peroxidase activity with the prerequisite of the presence of H2O2. In contrast, oxidase mimics can catalyze the oxidation of substrates without H2O2, delivering a higher signal-to-noise ratio than that of peroxidase mimics in practical applications. Herein, for the first time, two-dimensional (2D) nanosheets composed of iron phosphide embedded in a carbon matrix (FeP@C nanosheets) were found to demonstrate a robust oxidase-like property, different from those previously reported peroxidase mimics based on transition metal phosphides (TMPs). Based on this intriguing observation, the fluorescent substrate Amplex Red (AR) of peroxidase can be effectively oxidized by FeP@C nanosheets in the absence of H2O2. Benefiting from the oxidase-like enzymatic activity of the FeP@C nanosheets, a novel fluorescence sensing platform was developed for the detection of cysteine (Cys) and Cu2+. The outstanding performance of the 2D FeP@C nanosheets endows the proposed platform with superior sensitivity and selectivity compared to many previously reported approaches. Besides, the inherent features of simplicity, being label free, and low cost also allow this methodology to stand out among many other strategies, revealing its huge potential in practical analysis and detection applications.
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Journal of Cleaner Production
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2020
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IF 7.246
Bowei Shen,XueJun Yu,Farong Zhang,Wenxiu Jiang,Hui Yuan,Zhiquan Pan,Hong Zhou
A new method of the catalytic alcoholysis of Dioscorea zingiberensis C. H. Wright into diosgenin by magnetic solid acid in a Teflon-lined stainless-steel autoclave for the first time. The magnetic solid acid, Fe 3 O 4 @SiO 2 –SO 3 H, was prepared by the connecting the –SO 3 H groups on the surface of SiO 2 encapsulated Fe 3 O 4 microspheres . The synthesized catalysts were systematically analyzed by Fourier transform infrared (FT-IR) spectroscopy, thermogravimetric analyzer (TGA), X-ray diffraction (XRD), vibrating sample magnetometry (VSM), temperature programmed desorption of ammonia (NH 3 -TPD), scanning electron microscope (SEM), transmission electron microscope (TEM) and transmission electron microscope-mapping(TEM-mapping). To obtain the best conditions for the alcoholysis of Dioscorea zingiberensis C. H. Wright, single factor test was first utilized to determine the range of optimal conditions and optimized by response surface method . A three-level-three-factor Box-Behnken design was adopted to illustrate the effect of solid acid mass, solvent volume, reaction time and temperature on the yield of diosgenin. The optimum conditions obtained by response surface methodology were: 0.42 g Fe 3 O 4 @SiO 2 –SO 3 H, 4.38 mL solvent of ethanol, the reaction temperature at 100 °C and 6.09 h reaction time. At the optimal conditions, this method can reach the highest yield 2.64% from Dioscorea zingiberensis C. H. Wright. The yield of the new method was 21.66% higher than conventional sulfuric acid hydrolysis based on the analysis results of UV and HPLC. Importantly, the catalysts and solvents used in the alcoholysis process by the solid acid can be recovered, which is green and environmentally friendly, indicating that the catalytic alcoholysis with magnetic solid acid under hydrothermal conditions had a broad application prospect in diosgenin production.
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Nature Communications
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2021
·Vol. 12
·期 1
·1-10
·
IF 14.919
Sayed Mahmoud,Xu Feiyan,Kuang Panyong,Low Jingxiang,Wang Shengyao,Zhang Liuyang,Yu Jiaguo
Solar conversion of CO 2 into energy-rich products is one of the sustainable solutions to lessen the global energy shortage and environmental crisis. Pitifully, it is still challenging to attain reliable and affordable CO 2 conversion. Herein, we demonstrate a facile one-pot approach to design core-triple shell Mn, C-codoped ZnO hollow spheres as efficient photocatalysts for CO 2 reduction. The Mn ions, with switchable valence states, function as “ionized cocatalyst” to promote the CO 2 adsorption and light harvesting of the system. Besides, they can capture photogenerated electrons from the conduction band of ZnO and provide the electrons for CO 2 reduction. This process is continuous due to the switchable valence states of Mn ions. Benefiting from such unique features, the prepared photocatalysts demonstrated fairly good CO 2 conversion performance. This work is endeavoured to shed light on the role of ionized cocatalyst towards sustainable energy production.
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CHINESE CHEMICAL LETTERS
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2021
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IF 6.779
Min Zhang,Bolong Yang,Ting Yang,Yahui Yang,Zhonghua Xiang
Unremitting and intensive researches about efficient non-precious metal electrocatalysts are necessary for large-scale commercial applications of fuel cells, while iron and nitrogen co-doped carbon (Fe-N-C) materials has become one of the most promising electrocatalysts to replace Pt-based noble metal catalysts . However, the traditional Fe-doped ZIF with rhomb dodecahedron morphology limits the exposure of active sites and the utilization of atoms, even affecting the performance of the catalyst. Herein, a Fe/N co-doped catalyst with a flower-like morphology was prepared using ferric citrate source along with secondary NH 3 heat treatment. The optimal catalyst (termed as 4Fe citrate -N-C-3) showed distinguished oxygen reduction reaction (ORR) activity with a half-wave potential of 0.8 and 0.9 V ( vs . RHE) in acid and alkaline media, respectively. In addition, 4Fe citrate -N-C-3 maintained more than 80% of original activity even after 50,000 s which is superior to the benchmark Pt/C. The strategy of controlling morphology and composition is meaningful for the optimization of non-precious metal electrocatalysts for ORR in fuel cells or metal-air batteries .
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JOURNAL OF ALLOYS AND COMPOUNDS
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2021
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IF 5.316
Qiuyue Wang,Xiaofen Wu,Ji Huang,Siyi Chen,Yang Zhang,Chengjun Dong,Gang Chen,Lihong Wang,Hongtao Guan
With rapid advances in the portable electronics industry, the creation of microwave absorbing materials with high-performance to dissipate the unwanted electromagnetic wave is an important prerequisite. Herein, unique ternary organic-inorganic composites (C/Ni/PPy) were fabricated by hydrothermal method combined with in-situ polymerization approach. The correlation between structure, components, and microwave absorption capability is investigated in detail. The carbon matrix was prepared through a typical “carbonization-activation” procedure. Then, the PPy particles were decorated on the surface of the biomass carbon matrix incorporated with Ni particulates via an in-situ polymerization method. The microwave absorbing results suggest that the C/Ni/PPy ternary composites exhibit stronger dielectric loss and microwave absorption capabilities than C/PPy binary composites. A reflection loss of − 42.09 dB and an outstanding effective absorption bandwidth of 5.24 GHz are achieved simultaneously with a thickness of only 2.4 mm. The excellent microwave absorbing performances can be ascribed to the unique microstructure, enhanced polarization and the synergistic effects between dielectric loss and magnetic loss. The present work achieves a new paradigm to improve microwave absorption characteristics through the combination of dielectric components with magnetic materials. Furthermore, a prototype is proposed, which has broad application prospects for applications in next-generation wearable and portable electronics.
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INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
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2021
·Vol. 22
·期 18
·9668
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IF 5.924
Xiaoxuan Yu,Hui Li,Dongfa Lin,Weizhuo Guo,Zhihao Xu,Liping Wang,Shuwen Guan
Panax ginsengis a valuable traditional Chinese medicine in Northeast China. Ginsenoside, the active component of ginseng, has not been investigated much for its effects on aging and its underlying mechanism(s) of action. Here, we investigated the effects of total ginsenoside (TG), a mixture of the primary active ginsenosides fromPanax ginseng, on the lifespan ofCaenorhabditis elegans(C. elegans). We found that TG extended the lifespan ofC. elegansand reduced lipofuscin accumulation. Moreover, TG increased the survival ofC. elegansin response to heat and oxidative stress via the reduction of ROS. Next, we used RNA-seq to fully define the antiaging mechanism(s) of TG. The KEGG pathway analysis showed that TG can prolong the lifespan and is involved in the longevity regulating pathway. qPCR showed that TG upregulated the expression ofnrh-80,daf-12,daf-16,hsf-1and their downstream genes. TG also reduced the fat accumulation and promoted lipid metabolism. Moreover, TG failed to extend the lifespan ofdaf-16andhsf-1mutants, highlighting their role in the antiaging effects of TG inC. elegans. The four main constitution of TG were then confirmed by HPLC and included ginsenoside Re, Rg1, Rg2and Rd. Of the ginsenosides, only ginsenoside Rd prolonged the lifespan ofC. elegansto levels comparable to TG. These findings provided mechanistic insight into the antiaging effects of ginsenoside inC. elegans.Keywords:Panax ginseng;lifespan;lipid metabolism;stress-resistant;Caenorhabditis elegans
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ACS Catalysis
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2021
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IF 13.084
Xiangdong Long,Jia Wang,Guang Gao,Chao Nie,Peng Sun,Yongjie Xi,Fuwei Li
Direct oxidative amination of the sp3 C–H bond is an attractive synthesis route to obtain amides. Conventional catalytic systems for this transformation are based on transition metals and complicated synthesis processes. Herein, direct and efficient oxidative amination of the methyl C–H bond in a wide range of N-heterocycles to access the corresponding amides over metal-free porous carbon is successfully developed. To understand the fundamental structure–activity relationships of carbon catalysts, the surface functional groups and the graphitization degree of porous carbon have been purposefully tailored through doping with nitrogen or phosphorus. The results of characterization, kinetic studies, liquid-phase adsorption experiments, and theoretical calculations indicate that the high activity of the carbon catalyst is attributed to the synergistic effect of surface acidic functional groups (hydroxyl/carboxylic acid/phosphate) and more graphene edge structures exposed on the surface of carbon materials with a high graphitization degree, in which the role of acidic functional groups is to adsorb the substrate molecule and the role of the graphene edge structure is to activate O2.
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Nano Research
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2021
·Vol. 15
·期 1
·519-527
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IF 8.897
Zhou Dan,Zhang Leilei,Liu Xiaoyan,Qi Haifeng,Liu Qinggang,Yang Ji,Su Yang,Ma Jingyuan,Yin Jianzhong,Wang Aiqin
Fine-tuning of the coordination environment of single-atom catalysts (SACs) is effective to optimize their catalytic performances, yet it remains challenging due to the vulnerability of SACs. Herein, we report a new approach to engineering the coordination environment of M-N-C (M = Fe, Co, and Ni) SACs by using glutamic acid as the N/C source and pyrolysis atmosphere as a regulator. Compared with that in N 2 , NH 3 was able to promote the doping of N at T < 700 °C yet etch the N-species at higher temperatures, by which the M-N coordination number (CN) and the electronic structure were delicately tuned. It was found that the electron density of Ni single atoms increased with the decrease of Ni-N CN. As a consequence, the capability of Ni-N-C to dissociate H 2 was greatly enhanced and a higher catalytic activity in chemoselective hydrogenation of functionalized nitroarenes was achieved. Moreover, this modulation method could be applied to other transition metals including Fe and Co. In particular, the as-synthesized Co-N-C SAC afforded a turnover frequency of 152.3 h −1 with 99% selectivity to 3-vinylaniline in the hydrogenation of 3-nitrostyrene, which was the highest ever reported thus far and was at least one order of magnitude more active than state-of-the-art noble-metal-free M-N-C catalysts, demonstrating the great potential of engineering the coordination environment of SACs.
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JOURNAL OF CATALYSIS
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2021
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IF 7.92
Huiyuan Cheng,Zihao Fan,Xuemei Wu,Manman Feng,Wentao Zheng,Guangping Lei,Xiangcun Li,Fujun Cui,Gaohong He
Single-atom catalysts (SACs) with well-defined active sites provide an efficient route for catalyzing CO 2 reduction reaction (CO 2 RR). Although enormous attention has been focused on metal-N x moieties, understanding the effect of metal-C coordination and engineering of the hybrid metal-N/C sites have rarely been reported. Herein, we fabricated Co SACs with tunable isolated Co-N 5-x C x ( x = 1, 2, 3) sites supported on porous carbon frameworks. Benefiting from the difference in electronegativity of the coordinated N and C atoms, the CO Faradaic efficiency (FE CO ) enhanced considerably from 54% to 76% and 92% at −0.8 V vs . RHE for Co-N 4 C 1 , Co-N 3 C 2 , and Co-N 2 C 3 , respectively. Further density functional theory (DFT) calculations uncover that the increased ratio of Co-C coordination induced electron enrichment of Co atoms and upper-shift the d -band center to near Fermi level, and thus favorably promotes the electron-donating ability of Co centers and strengthens the adsorption of *COOH.
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Journal of Physical Chemistry C
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2021
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IF 4.126
Chen Ding,Zijie Mao,Jia-Shun Liang,Xianxian Qin,Qing Zhang,Fan Yang,Qing Li,Wen-Bin Cai
The commercialization of proton exchange membrane fuel cells (PEMFCs) calls for the development of active and durable Pt-based catalysts for oxygen reduction reaction (ORR) by means of a cost-effective and environmentally benign protocol. We report herein an all aqueous phase preparation of carbon supported Au-modified Pt–Co alloy catalyst (Au/Pt–Co/C), which involves the dimethylamine borane co-reduction of aqueous Pt(II) and Co(II) precursors to form a Pt–Co/C catalyst and the ethanol reduction of an aqueous Au(III) precursor to form Au/Pt–Co/C. This Au/Pt–Co/C catalyst not only shows a greatly enhanced ORR activity like the homemade Pt–Co/C and state-of-art Pt–Co/C(com) catalysts as compared to the Pt/C catalyst but also exhibits a much higher durability over the Pt/C(com), homemade Pt–Co/C, and state-of-art Pt–Co/C(com) catalysts in accelerated degradation tests (ADTs) with both half-cell and single-cell configurations. Specifically, the maximum power density of a PEMFC involving the Au/Pt–Co/C cathode suffers only a 6% loss after 30 000 cycles of a standard ADT while that involving the state-of-art Pt–Co/C(com) suffers a 37% loss. This research provides an alternative route to prepare efficient and durable Pt-based ORR catalysts toward a widespread application of PEMFCs.
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JOURNAL OF HAZARDOUS MATERIALS
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2021
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IF 10.588
Cheng Zeng,Yan Wang,Tong Xiao,Zhicheng Yan,Jinquan Wan,Quanmo Xie
To improve the efficacy of organic pollutant removal using sulfate radicals, we designed MIP@C-Fe-Nx, a molecularly imprinted material capable of targeting the degradation of tetrabromobisphenol A (TBBPA), which can be used as both adsorbent and catalyst to recognize and degrade Tetrabromobisphenol A (TBBPA) accurately, and the final removal rate of TBBPA can reach 104.6 mg·g −1 . Based on the synergistic effects of MIP@C-Fe-Nx on the excellent organic pollutant recognition and catalytic performance, low concentrations of TBBPA can be pre-targeted, concentrated, and fixed on the surface of MIP, and degraded simultaneously in-situ by·OH and SO 4 •- which are produced by activating PS with C-Fe-Nx. Recognition experiments demonstrated that MIPs had perfect performance in recognizing and adsorbing TBBPA and debromination intermediates. The DFT calculations and HPLC-MS analysis indicated that MIP@C-Fe-Nx had a targeted recognition and accumulation for TBBPA and debromination intermediates, for example, dibromobisphenol A, monobromobisphenol A, and bisphenol A, thus avoid the formation of toxic intermediates causing secondary contamination.
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CHEMICAL ENGINEERING JOURNAL
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2021
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IF 13.273
Shiqi Wang,Wenyi Huo,Feng Fang,Zonghan Xie,Jian Ku Shang,Jianqing Jiang
Recently, high entropy alloy (HEA) based materials have been vigorously explored as viable catalysts in water electrolysis for their unique properties. However, the synthesis of efficient and robust high entropy catalysts remains a challenge. Here a facile and scalable approach is reported to synthesize advanced HEA (CoNiCuMnAl)/C nanoparticles from the polymetallic Metal–organic framework (MOF). The novel core-shell nanoarchitectures feature face-centered cubic HEA wrapped in ultra-thin carbon shell. The optimized catalyst (deposited upon Ni foam) boosted alkaline Oxygen evolution reaction (OER) (in 1.0 M KOH) with an ultralow overpotential of 215 mV at 10 mA/cm 2 (also by a low Tafel slope of 35.6 mV dec −1 ). The enhanced performance is closely tied to surface reconstruction (i.e., formation of oxyhydroxide catalytic active species) and the high entropy effect, revealed by Fourier-transformed alternating current voltammetry (FTACV) and in-situ Raman spectrum analysis, in conjunction with Density Functional Theory (DFT) computations. Furthermore, the new design showed excellent long-term OER stability with negligible decay through 30 h testing (under 200 mA cm −2 ). The present work demonstrates the feasibility and advantage of utilizing highly efficient and durable high entropy alloys for catalyzing electrochemical water splitting process.
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