Frontiers of Optoelectronics
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2022
·Vol. 15
·期 1
·1-9
·
IF 0
Zhou Xingwei,Zhang Wei,Zhang Zunhao,Wang Zizhun,Zou Xu,Li Dabing,Zheng Weitao
The oriented two-dimensional porous nitrogen-doped carbon embedded with CoS 2 and MoS 2 nanosheets is a highly efficient bifunctional electrocatalyst. The hierarchical structure ensures fast mass transfer capacity in improving the electrocatalytic activity. And the greatly increased specific surface area is beneficial to expose more electrocatalytically active atoms. For oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) tests in 1 mol/L KOH solution, only 194 and 140 mV overpotential are required to achieve a current density of 10 mA/cm 2 , respectively. Our research provides an effective strategy for synergizing the individual components in nanostructures for a wide range of electrocatalytic reactions. Graphical Abstract
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PubMed
SENSORS AND ACTUATORS B-CHEMICAL
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2022
·
IF 9.221
Weiyi Bu,Yan Zhang,Qixuan Qin,Yuliang Li,Zhijie Zhou,Changhua Hu,Xiaohong Chuai,Tianshuang Wang,Peng Sun,Geyu Lu
In our work, CdS nanocrystals were simply prepared via coprecipitation method and subsequent annealing process (300, 400, 500 °C). X-ray powder diffraction (XRD) and the transmission electron microscope (TEM) etc. methods were used to analyze structure morphologies of the samples. The unannealed CdS nanocrystal is cubic, its phase evolution depends on annealing temperature. At 300 °C, its cubic phase was remained. Annealing at 400 °C makes small amount of hexagonal phase produced and cubic/hexagonal homojunctions were formed. Thorough phase transition to hexagonal phase was completed at 500 °C. The sensing properties based on the synthesized CdS nanocrystals with different phase structures were measured. The CdS-400 based sensor had the highest sensitivity to n-propanol, which was 41 at the optimum temperature of 225 °C. The response time was less than 1 s and the best selectivity was also obtained. The greatly enhanced gas sensing performance may be attributed to cubic/hexagonal CdS homojunction.
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高影响因子
CATALYSIS TODAY
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2022
·
IF 6.562
Zhen Liu,Hu Li,Yi Wang,Yu Wang,Peng Peng,Xinmei Liu
Due to higher thermal and hydrothermal stability, suitable acidity properties, Beta zeolite is considered as promising catalyst for naphtha catalytic cracking process. However, high cost and environmental pollution issue limit its industrial application by using high content of N-containing organic structural directing agent (SDA). In this paper, different SiO 2 /Al 2 O 3 ratios of Beta zeolites were prepared assisting by seeds induced method with low SDA and cheap industrial silica sol as the silicon source. Physical and chemical properties of as-prepared Beta zeolites were characterized by XRD, N 2 adsorption-desorption, NH 3 -TPD, Py-FTIR and SEM. N-Heptane was used as model compound for catalytic cracking performance evaluation. The results showed that Beta zeolite with high SAR was successfully synthesized, which had well defined crystallinity, proper specific surface area and pore structure, high B/L ratio and strong acid site. n-Heptane catalytic cracking performance showed high yield of low-carbon olefins with relative low activity on hydrogen transfer reaction and coke formation.
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高影响因子
NEW JOURNAL OF CHEMISTRY
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2022
·Vol. 46
·期 35
·16752-16763
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IF 3.925
Kai Guo,Aizeng Ma,Zijian Wang,Jinzhi Li,Bingfeng Wu,Tong Liu,Dadong Li
The design of various hierarchical structures and morphologies of ZSM-22 zeolite catalysts is attempted through a post-treatment using different concentrations of NaOH and subsequently treating with HCl solution including fluosilicic acid (H2SiF6) and then loading Pt on their surfaces. The effects of samples on textural characters, acidity, as well as n-heptane catalytic hydroisomerization evaluation were examined. The formation process of the hierarchical structures was further investigated. Test and evaluation results indicated that samples treated with 0–0.5 M NaOH and subsequently treated with 6.0 M HCl and 0.1 M H2SiF6 were much more controllable and reasonable due to the better structure-activity relationship of the catalyst by changing crystal morphologies and introducing hierarchical structures. Indeed, PZH-0.3 exhibited 81.1% of the highest n-heptane conversion and 76.4% of total i-heptane yield in the n-heptane catalytic hydroisomerization process at 260 °C, PZH-0.5 displayed 13.6% of the maximum multi-branched i-heptane yield, which was above 104.1% in comparison with PZ-0 at 320 °C. Moreover, PZH-0.3 presented the highest n-butane yield, which possessed a proportion of 65.9% in the butane component of cracking products at 340 °C and improved an average of 16% and 22 times when utilizing PZ-0 and Pt/ZSM-5 catalysts. Additionally, the mechanism of the reaction process is briefly depicted according to the distribution of the reaction products. The regulation of zeolite both on crystal morphologies and pore hierarchy has obvious advantages in the hydroisomerization process, which can improve the composition of multi-branched isomers with high octane number effectively as well as supply raw materials for the chemical industry.
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高影响因子
DALTON TRANSACTIONS
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2022
·Vol. 51
·期 26
·10160-10168
·
IF 4.569
Li Luo,Siran Xu,Xin Yu,Zhe Wang,Wenjing Li,Yeshuang Du,Min Ruan,Qi Wu
Developing low-cost, high-performance and corrosion-resistant catalysts for water splitting is anticipated, but it will also be a big challenge. In this study, nanowall-like N-Ni5P4/Ni2P/NF (N-NiP/NF) was synthesized by a simple two-step method involving hydrothermal treatment and phosphorylation. The catalyst has good catalytic activity for the OER, and only 160 mV is required to achieve a current density of 10 mA cm−2 in 1 M KOH, which is even better than RuO2, with good corrosion resistance. In addition, N-Co2P/Ni2P/NF (N-CoP/NF) was synthesized by the same method with good electrocatalytic properties and good conductivity towards the HER. N-NiP/NF was used as the anode and N-CoP/NF was used as the cathode to form the N-NiP//N-CoP double electrode system, which showed excellent electrolytic performance for water splitting, requiring only 1.48 V to reach 10 mA cm−2. This is mainly due to the strong electronegativity of N that makes the N doping induce the electron transfer process, which results in a high catalytic activity of the adjacent transition metal atoms and thus promotes the electrolysis of water, as well as the unique vertical nanowall-like structure, which gives the material a large surface area and accessibility to active sites, facilitating the adsorption of water molecules and catalytic reactions. In addition, the unique structure favors the diffusion of water molecules and the release of gaseous products, ensuring close contact between the catalyst and the electroactive material. This simple non-metallic N doping strategy provides a new way to produce efficient non-precious metal catalysts.
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高影响因子
Chemosensors
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2022
·Vol. 10
·期 8
·334
·
IF 4.229
Shangxin Guo,Jing Lan,Bo Liu,Baixiu Zheng,Xingchu Gong,Xiaohui Fan
The carbon quantum dot (CQD) paper-based analytical device (PAD) has drawn great attention and is being intensively explored. However, the construction of a continuous flow CQD synthesis device remains challenging. In this work, a continuous flow reaction apparatus was constructed to synthesize nitrogen-doped CQDs using a mixed-solvent system of tetraethylene glycol and water. The optical properties of the CQDs were characterized. The CQDs were found to be quenched by phenolics such as chlorogenic acid, salvianolic acid B, and rutin. The CQD PAD was prepared for the determination of the total phenolic content of honeysuckle extracts. A smartphone was used to test the analytical performance of the CQD PAD. The results demonstrated that the degree of fluorescence quenching of the CQDs showed a linear relationship with the concentration of the added chlorogenic acid solution. This method was compared with the total phenolic assay in the Chinese Pharmacopoeia, and the statistical test showed no significant difference between their results. With aqueous tetraethylene glycol as the solvent for the synthesis, the continuous flow reactor for CQD preparation could be easily set up. The CQD PAD is convenient, cheap, and expected to be used for the rapid quality detection of traditional Chinese medicines.Keywords:Chinese medicine quality;carbon quantum dots;PAD;total phenolic content;continuous flow synthesis;tetraethylene glycol
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高影响因子
Polymers
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2022
·Vol. 14
·期 18
·3889
·
IF 4.967
Jing Li,Fanxun Lv,Ran Yang,Liping Zhang,Wei Tao,Guotao Liu,Hui Gao,Ying Guan
Medulla tetrapanacisis composed of a lignocellulosic biopolymer and has a regular porous structure, which makes it a potential biomass material for preparing porous N-doped biochar. Herewith, N-dopedMedulla tetrapanacisbiochar (UBC) was successfully prepared by modification with urea and NaHCO3under pyrolysis at 700 °C. The nitrogen-containing groups were efficiently introduced into biochar, and the micro-pore structures of the UBC were developed with sizeable specific surface area, which was loaded with massive adsorption sites. The adsorption kinetics and isotherms of the UBC conformed to pseudo-second-order and Langmuir model. The superior adsorption capacities of the UBC for methylene blue (MB) and congo red (CR) were 923.0 mg/g and 728.0 mg/g, and the capacities for Cu2+and Pb2+were 468.5 mg/g and 1466.5 mg/g, respectively. Moreover, the UBC had a stronger affinity for Cr3+and Fe3+in multiple metal ions and retained at a preferable adsorption performance for dyes and heavy metals after five cycles. Precipitation, complexation, and physical adsorption were the main mechanisms of the UBC-adsorbing metal ions and dyes. Thus, lignocellulosic biochar has great potential for removing dyes and heavy metals in aqueous solutions.Keywords:urea modification;efficient adsorption;porous biochar
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高影响因子
ACS Applied Nano Materials
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2022
·
IF 6.14
Jiang Zhao,Shumeng Wang,Lijuan Gao,Da Zhang,Yanyan Guo,Rongqing Xu
As an energy storage component of wearable electronics, planar micro-supercapacitors (MSCs) hold great advantages in terms of flexibility, miniaturization, and integration. However, the preparation process of MSCs is rather cumbersome. A simple, fast, and efficient technique for preparing MSCs is still of strong desirability. Herein, a fast and efficient laser direct writing technique is proposed to in situ fabricate NiO nanoparticles anchored on N-doped laser-induced graphene (NiO/NLIG) composite electrodes on account of the formation principle of the polyimide (PI) film, which are subsequently assembled into high-performance flexible planar MSCs. The as-assembled NiO/NLIG MSCs can achieve a remarkable areal specific capacitance of 25.11 mF cm–2, a superior energy density of 1.88 mW h cm–2 at a high power density of 0.02 mW cm–2, excellent bendability, and good cycling performance. Furthermore, due to advantages of consistency and stability of laser direct writing, the proposed high-performance planar NiO/NLIG MSCs with consistency and stability can be easily modularized and integrated to provide customized requirements and are the most promising crucial micro-power energy storage components for flexible integrated electronics.
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高影响因子
ANALYTICAL CHEMISTRY
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2022
·
IF 8.008
Li Fu,Xiancheng Liu,Ying Zeng,Qingqing Zhang,Bin Zhang,Xuwen Gao,Guizheng Zou
The electrochemiluminescence (ECL) bioassay is prominently carried out with the involvement of the coreactant. To remove the detrimental effects of the coreactant on the ECL of luminophores, herein, a promising ECL immunoassay strategy with biocompatible nanoparticles as the luminophore is proposed, which involves directly and electrochemically oxidizing the luminophore methionine-capped Au (Met@Au) nanocrystals (NCs) without the participation of any coreactant. Met@Au NCs are a kind of n-type nanoparticles, and they can be electrochemically injected with valence band (VB) holes around +0.80 and +1.10 V (vs Ag/AgCl). The electrochemically injected exogenous VB hole can recombine with the endogenous conduction band electron of Met@Au NCs and eventually bring out two coreactant-free and near-infrared ECL processes around 0.80 V (ECL-1) and 1.10 V (ECL-2). The intensity of coreactant-free ECL is primarily determined by the electrochemical oxidation-induced hole-injection process. ECL-2 is considerably stronger than ECL-1 and can be exploited for determining the carcinoembryonic antigen (CEA) in a sandwich immunoassay procedure with a linear range from 0.1 to 50 pg/mL as well as a limit of detection of 0.03 pg/mL (S/N = 3).
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高影响因子
Materials
·
2022
·Vol. 15
·期 15
·5331
·
IF 3.748
Min Sun,Pengyu Zhang,Qingmin Li,Guowu Tang,Ting Zhang,Dongdan Chen,Qi Qian
N-type bismuth telluride (Bi2Te3) based thermoelectric (TE) fibers were fabricated by thermal drawing and Bridgman annealing, and the influence of Bridgman annealing on the TE properties of n-type Bi2Te3-based TE fibers was studied. The Bridgman annealing enhanced the electrical conductivity and Seebeck coefficient because of increasing crystalline orientation and decreasing detrimental elemental enrichment. The TE performance of n-type Bi2Te3-based TE fibers was improved significantly by enhancing the power factor. Hence the power factor increased from 0.14 to 0.93 mW/mK2, and the figure-of-merit value is from 0.11 to 0.43 at ~300 K, respectively.Keywords:n-type Bi2Te3;thermoelectric fibers;thermal drawing;Bridgman annealing
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高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2021
·
IF 5.316
Kang Ji,Katarzyna Matras-Postolek,Ruixia Shi,Ling Chen,Quande Che,Junpeng Wang,Yunlong Yue,Ping Yang
MoS 2 /CoS 2 heterostructures on nitrogen-doped carbon nanosheets as an efficient electrocatalyst for hydrogen evolution reaction (HER) are prepared using zeolitic imidazolate frameworks-67 as precursors. Two dimensional (2D)/2D MoS 2 /CoS 2 heterostructures consist of layered CoS 2 and MoS 2 . The (210) facet of CoS 2 and the (002) facet of MoS 2 contacted vertically resulted in improved electrons and holes transfer in the interface. The ratios of CoS 2 /MoS 2 plays an important role to get high performance (CoS 2 /MoS 2 /NC-n%, e.g. n = 20, 25, 30, 35 wt%). Meanwhile, sample CoS 2 /MoS 2 /NC-25% revealed the best HER activity, suggesting the sample has the largest number of active sites and the fastest electron transfer rate. In addition, sample CoS 2 /MoS 2 /NC-25% exhibited the lowest onset potential of 51 mV, the lowest potential of 215 mV at 10 mA cm −2 , and the smallest Tafel slope of 80.0 mV dec −1 . The result is utilizable for the construction of heterostructures with excellent HER performance.
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高影响因子
NANO
·
2021
·
IF 1.556
Mengting Zhang,Xiaorong Li,Hong Xiao,Bin Zhao,Wei Bian
Graphene quantum dots (GQDs) have been extensively used in biosensors and bioimaging. Heteroatom-doped GQDs can regulate material properties and endow them to improve structural and physicochemical properties. In this work, N,S-GQDs were prepared through a high-temperature pyrolysis method using L-cysteine and citric acid as the precursors. The morphology and structure of nanocomposites were identified by TEM, X-ray diffractometer (XRD), X-ray photoelectron spectrometer (XPS), and FTIR. The as-prepared N,S-GQDs show bright blue fluorescence with satisfactory fluorescence quantum yield. N,S-GQDs display significant response to riboflavin, achieving a low detection limit of 27 nM. The reaction of N,S-GQDs to riboflavin is mainly governed by static quenching. The detection of riboflavin in real samples has been performed to demonstrate its practical application. The obtained N,S-GQDs have low cytotoxicity and have been applied successfully in cell imaging.
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危险品化学品经营许可证（带存储）