SENSORS AND ACTUATORS B-CHEMICAL
·
2018
·
IF 5.667
Yabin Zhang,Kai Fung Chan,Ben Wang,Philip Wai Yan Chiu,Li Zhang
Fluorescent carbon dots hold great promise in biomedical real-time tracking due to their outstanding optical properties and biocompatibility. Here, we report a one-pot synthetic strategy to produce multi-doped carbon dots (MCDs) with bright and color-tunable emission. The resultant MCDs are doped by abundant biogenic elements (O, N, P), so that they contain a variety of surface functional groups. Such hetero-doping and functionalization make MCDs display strong fluorescent emission and excitation-wavelength-dependent characteristic, good aqueous solubility as well as high photo-stability and ion-stability. Moreover, the as-prepared MCDs response to the change of pH values and exhibit high selective and sensitive detection of Fe 3+ ions under blue light illumination with the limit of detection (LOD) of 15.9 nM. Such a Fe 3+ sensing ability is further demonstrated in real water samples and extended to intracellular multi-color monitoring of Fe 3+ . More interestingly, the MCDs can also sense the gastrointestinal bacteria Escherichia coli , exhibiting linear sensing dependent behavior. With low cytotoxicity and tunable emission, such MCDs hold great potential as efficient multi-color probes and imaging agents for clinical diagnosis.
研究领域:
生物医学
·
材料科学
·
分析化学
✓ 已验证
DOI
高影响因子
Nanomaterials
·
2022
·Vol. 12
·期 5
·832
·
IF 5.719
Tao Wang,Oluwafunmilola Ola,Malcom Frimpong Dapaah,Yuhao Lu,Qijian Niu,Liang Cheng,Nannan Wang,Yanqiu Zhu
Recently, electrocatalysts for oxygen reduction reaction (ORR) as well as oxygen evolution reaction (OER) hinged on electrospun nanofiber composites have attracted wide research attention. Transition metal elements and heteroatomic doping are important methods used to enhance their catalytic performances. Lately, the construction of electrocatalysts based on metal-organic framework (MOF) electrospun nanofibers has become a research hotspot. In this work, nickel-cobalt zeolitic imidazolate frameworks with different molar ratios (NixCoy-ZIFs) were synthesized in an aqueous solution, followed by NixCoy-ZIFs/polyacrylonitrile (PAN) electrospun nanofiber precursors, which were prepared by a simple electrospinning method. Bimetal (Ni-Co) porous carbon nanofiber catalysts doped with nitrogen, oxygen, and sulfur elements were obtained at high-temperature carbonization treatment in different atmospheres (argon (Ar), Air, and hydrogen sulfide (H2S)), respectively. The morphological properties, structures, and composition were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), selected area electron diffraction (SAED), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). Moreover, the specific surface area of materials and their pore size distribution was characterized by Brunauer-Emmett-Teller (BET). Linear sweep voltammetry curves investigated catalyst performances towards oxygen reduction and evolution reactions. Importantly, Ni1Co2-ZIFs/PAN-Ar yielded the best ORR activity, whereas Ni1Co1-ZIFs/PAN-Air exhibited the best OER performance. This work provides significant guidance for the preparation and characterization of multi-doped porous carbon nanofibers carbonized in different atmospheres.Keywords:electrospinning;porous carbon nanofibers;oxygen reduction reaction;oxygen evolution reaction
研究领域:
材料科学
·
电催化
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Nanoscale
·
2019
·Vol. 11
·期 18
·8950-8958
·
IF 6.97
Hui Yang,Shunxing Li,Huiwu Yu,Fengying Zheng,Luxiu Lin,Jie Chen,Yuehai Li,Ye Lin
Control of the active sites/centers plays an important role in the design of novel electrode materials with unusual properties and achievement of sensors with high performance. In this study, three-dimensional (3D) freestanding multi-doped hollow carbon spheres (N–Co–Fe–HCS) with a layer thickness of 30 nm, which contained multiple active sites of the heteroatom N and transition metals (Co and Fe), were synthesized via a simple template method (with SiO2 as the template) and cost-efficient in situ self-polymerization, self-adsorption/reduction and carbonization strategies. Moreover, a series of hollow carbon sphere composites of the same family (N–HCS, N–Co–HCS and N–Fe–HCS) were prepared by this sensible process using the same method and precursors but different doping elements. These differences lead to different active sites/centers from hollow carbon spheres and improved electrocatalytic activities for dihydroxybenzene isomers. Furthermore, N–Co–Fe–HCS as an electrochemical sensor exhibited excellent simultaneous qualitative and quantitative determination performance for catechol (CC) and hydroquinone (HQ). The detection limit and the linear range were 75 nmol L−1 and 0.5–500 μmol L−1 for CC and 80 nmol L−1 and 0.5–1500 μmol L−1 for HQ, respectively. The interference from the components coexisting in river water on the detection of CC and HQ was not observed. These results indicate that high-performance electrochemical sensors can be constructed by in situ multi-element doping into electrode materials to achieve multi-active sites.
研究领域:
材料科学
·
分析化学
✓ 已验证
DOI
高影响因子
DYES AND PIGMENTS
·
2023
·
IF 4.5
Changxing Wang,Xiameng Li,Tingting Li,Yiru Wang,Guoqiang Guo,Siyuan Tang,Chenjie Gu,Da Chen
Multiple emission GQDs have always been the focus of researchers due to the unique emission characteristics and high-level application capabilities. Nevertheless, the most of GQDs with double emissions are formed by different chemical reactions, and the realization of double emission by adjusting the solvent environment is rarely reported. Here, the multi-doped and double-peak emissive GQDs (MD-GQDs) have been synthesized via one pot hydrothermal synthesis and re-dispersed in solvents with different polarity. Systematic characterizations of optical property indicate that the solvent polarity related double-peak emission photoluminescence is ascribed to the existence of multi-emissive centers in MD-GQDs from aromatic C O bond and surface/edge state (C–N/C–F). Furthermore, the double emission fluorescent mechanism of MD-GQDs has been proposed due to the electrostatic interaction between MD-GQDs and solvent molecules , which induces intramolecular charge transfer (ICT) effect in MD-GQDs. Finally, based on the unique solvent-induced discoloration behavior of MD-GQDs, a multi-mode anti-counterfeiting application based on organic solution as the secret key with easy operation and high visual effect is developed.
研究领域:
材料科学
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光学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF ENERGY RESEARCH
·
2022
·Vol. 46
·期 12
·17056-17067
·
IF 4.672
Tao Lyu,Shiying Lin,Lanlan Mo,Feijun Wang,Ziqiang Shao
Summary Natural polyelectrolyte complex has designable structure, unique advantages of composite and strong intermolecular or intramolecular force without chemical cross-linking agents, showing the advantages of good biodegradability and low toxicity. This work reports an application research of natural polyelectrolyte in energy storage device. A multi-doped hierarchically porous carbon is fabricated from polyelectrolyte of sodium lignosulfonate and chitosan and used as electrode material of supercapacitor. The material characterization reveals its large specific surface area of 1768 m 2 g −1 , pore volume of 0.94 cm 3 g −1 with optimum 3D porous structure, and high heteroatom (oxygen, nitrogen, and sulfur) concentration. Benefit from these, the electrodes it made exhibit 354 F g −1 specific capacitance at 1 A g −1 current density, outstanding rate retention of 82.9% at a testing environment of 20 A g −1 , and 97.8% capacitance retention in 3 M KOH electrolyte after 10 000 cycles. Using this material, all-solid symmetric supercapacitor devices show 30.11 Wh kg −1 energy density at 520.88 W kg −1 power density and retains 20.90 Wh kg −1 at 1.03 kW kg −1 . These remarkable electrochemical performances prove the promising porous carbon in this work as electrode material with excellent performance for supercapacitors.
研究领域:
材料科学
·
电化学
·
能源存储
·
纳米材料
·
功能材料
·
碳材料
✓ 已验证
DOI
高影响因子
SOLAR ENERGY MATERIALS AND SOLAR CELLS
·
2022
·
IF 7.305
Yun Da,Jialei Zhou
Calcium-looping thermochemical energy storage is a promising candidate in concentrated solar power plants. Solar-driven calcium-looping process via directly capturing sunlight can solve the challenges faced by traditional calcium-looping system, such as excessively high wall temperature, large thermal resistance , and low utilization efficiency of solar energy. In this work, we aim to improve optical absorption and cyclic stability of the direct solar-driven calcium-looping process with modified calcium-based materials for thermochemical energy storage. A simple sol-gel method was used to synthesize calcium-based composites via multi-doping strategy and the doping elements mainly included cerium (Ce), cobalt (Co), and manganese (Mn). Firstly, the role of calcium-based materials using single-doping element on the performance of thermochemical energy storage was revealed. The doping of Ce alone could generate oxygen vacancies and increase the adsorbed ability of CO 2 , accelerating the carbonization kinetics of CaO. The doping of Co alone played an important role in enhancing optical absorption while the doping of Mn alone was beneficial to cycling stability via providing a strong framework to inhibit sintering effect. Calcium-based materials using multi-doping strategy retained the function of single-doping effect on the performance of calcium-looping thermochemical energy storage, synergistically improving optical absorption, carbonization kinetics, and cyclic stability. Compared to pure CaCO 3 , Ce/Co/Mn co-doped Ca-based materials (CaCO 3 /5Ce–3Co–6Mn) exhibited a higher light trapping ability with optical absorption reached to 83.26% and more excellent cycling stability with effective conversion rate remained above 64% after 20 cycles. Furthermore, an interesting phenomenon that phase transformation of doped metal oxides formed by multi-doping strategy occurred during the calcination/carbonation cycling process was discovered and the underlying mechanisms were clarified. Finally, the feasibility of experiment by directly capturing concentrated sunlight to drive CaCO 3 decomposition for storing solar energy was verified.
研究领域:
材料科学
·
能量存储
·
太阳能
·
热化学
✓ 已验证
产品关联
DOI
高影响因子
Catalysis Science & Technology
·
2024
·Vol. 14
·期 9
·2630-2637
·
IF 4.4
Peng Hu,Qijing Zhang,Xiaodong Lu,Zihao Zuo
The electrochemical synthesis of hydrogen peroxide through the two-electron oxygen reduction (2e− ORR) pathway represents a promising and environmentally friendly technique. The development of efficient electrocatalyst is crucial to enable this process. In this work, a nickel, nitrogen and oxygen co-doped nanocatalyst (Ni–N/Cox) was prepared and its oxygen reduction performance was assessed using linear sweep voltammetry experiments. The results revealed excellent 2e− ORR activity of the catalyst under alkaline condition with a remarkable selectivity for hydrogen peroxide of up to 96%. Comprehensive characterization techniques including SEM, TEM, XPS, XRD and FT-IR were employed. These analyses indicated that the surface of the Ni–N/Cox catalyst contained abundant oxygen-containing functional groups and active nitrogen species, with the Ni element uniformly dispersed on the surface of the carbon substrates. Based on our findings, we propose that the excellent 2e− ORR activity and selectivity of the catalyst stem from the formation of Ni–N2O2 active centers on the carbon surface. Additionally, the presence of abundant oxygen functional groups and active nitrogen species on the carbon surface further enhanced the catalytic performance of bulk carbon materials. This study presents a new avenue for the development of efficient and cost-effective 2e− ORR catalysts, with potential implications for various electrochemical applications.
研究领域:
电化学
·
催化
·
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）