Search

The development of high performance triethylamine (TEA) sensors for the protection of human safety is essential. Herein, we reported a promising semiconductor metal oxide (SMO) gas sensor based on Pr-doped ZnO nanospindles as the sensing materials for the detection of TEA. The elemental composition and micromorphology of the as-prepared samples were systematically analyzed. The gas sensing performance of the pristine, 1 mmol%, 2 mmol%, and 3 mmol% Pr-ZnO sensor was evaluated. Among them, the 2 mmol% Pr-ZnO sensor exhibited the highest response value for TEA gas, and reached 158.0 towards 50 ppm TEA at 200 °C, which was about 10.0-fold higher than the response value of the pristine ZnO sensor. In addition, the 2 mmol% Pr-ZnO sensor also showed good reproducibility, rapid response/recovery time (10/46 s), theoretical limit of detection (168 ppb), outstanding long-term stability, and excellent selectivity for TEA gas. [Display omitted] • A series of the ZnO nanospindles were prepared via one-pot precipitation method. • The 2 mmol% Pr-ZnO sensor showed the best response of 158 to 50 ppm TEA at 200 °C. • The enhanced TEA sensing performance of Pr-ZnO were discussed. [ABSTRACT FROM AUTHOR]

ZnFe 2 O 4 nanoparticles with diameter of ca.10 nm were successfully synthesized under hydrothermal conditions without using any surfactant or structure-directing agents. The structure, composition and morphology of the samples were characterized by means of powder X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), field-emission scanning electron microscopy (SEM), transmission electron microscopy (TEM), diffuse reflectance spectra (DRS) and the Brunauer–Emmett–Teller (BET) surface area measurement. The results showed that the mole ratio of reactants ZnO to FeCl 3 played an important role in controlling the composition and morphology of the products. BET specific surface area of ZnFe 2 O 4 nanoparticles was evaluated to be 115.6 m 2 g −1 . Interestingly, as-prepared ZnFe 2 O 4 nanoparticles displayed enhanced gas sensing performance to acetone, which response value reached 39.5 for 200 ppm acetone gas at lower optimum working temperature of 200 °C, in comparison with the precursor ZnO (4.2) at the same condition. The gas sensing property demonstrates that as-prepared ZnFe 2 O 4 has potential applications in the detection of acetone. [ABSTRACT FROM AUTHOR]

Highlights: [•] Cu2SnSe3 nanocrystals was successfully synthesized by a “hot-injection” protocol. [•] Low-toxicity, inexpensive Se precursor was used. [•] The as-prepared CTSe nanocrystals can be used as promising thermoelectric materials. [ABSTRACT FROM AUTHOR]

Abstract: Tremelliform Co0.85Se nanosheets have been successfully synthesized through a hydrothermal reaction of Co(NO3)2·6H2O, Na2SeO3 and N2H4·H2O without using any surfactant or structure-directing agents. The hydrothermal reaction products were confirmed as pure phase of Co0.85Se. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) characterizations further showed that the obtained products were flexible tremelliform nanosheets, which were composed of the slices with thickness of ca. 10nm. Additionally, detailed investigation indicated that the formation of the tremelliform Co0.85Se nanosheets was strongly dependent on the reaction temperature, reaction time and reactant ratios. The obtained tremeliform Co0.85Se nanosheets displayed ferromagnetic properties at room temperature according to the magnetic measurement. More interesting, the as-prepared Co0.85Se nanosheets showed efficient catalytic performance for decomposition of hydrazine hydrate at room temperature. In addition, the stability and reversibility of Co0.85Se nanosheets as catalysts are also excellent, indicating that these nanomaterials can be used as long term catalysts in wastewater treatment. [Copyright &y& Elsevier]

Transition metallic oxides have attracted considerable attention for supercapacitor applications because of their superior electrochemical performance at relatively low cost. Co 3 O 4 /NiO nanofilms were successfully prepared by calcination of precursor α-Co(OH) 2 /α-Ni(OH) 2 . XRD, XPS, SEM and TEM techniques were used to characterize the composition and morphology of as-prepared samples. The results demonstrated that Co 3 O 4 /NiO nanofilms presented graphene-like morphology with shrinkage and wrinkles. The Brunauer–Emmett–Teller (BET) measurement showed that specific surface area of Co 3 O 4 /NiO was 176.5 m 2 /g. Electrochemical properties tests indicated that the Co 3 O 4 /NiO nanofilms had a higher specific capacitance and better rate capability than that of precursor α-Co(OH) 2 /α-Ni(OH) 2 at high current density. As to the cycling performance, the specific capacitance of Co 3 O 4 /NiO electrode would first increase from 556 F/g to 710 F/g quickly at 2 A/g after 80 cycles and then remained stable. Therefore, compared with that of precursor α-Co(OH) 2 /α-Ni(OH) 2 , the capacitance performance of as-prepared Co 3 O 4 /NiO nanofilms was improved after calcination. The possible reason for the enhancement of capacitance performance was discussed. [ABSTRACT FROM AUTHOR]

Metal-organic framework (MOF) can be used as sacrificial templates for preparing metal oxides with unique hollow structures. The heterojunction formed between two metal oxides is conducive to improvement of gas sensor performance. Herein, MOF compounds containing In with hexagonal prism morphology were synthesized first, and then annealed to obtain uniform hexagonal In 2 O 3 hollow microtubes. Subsequently, the surface of In 2 O 3 hollow microtubes was decorated by the Pr-doped SnO 2 nanoparticles (NPs) in solution under stirring, and the Pr-SnO 2 /In 2 O 3 composite was obtained. Various characterization techniques confirmed the successful preparation of the Pr-SnO 2 NPs/In 2 O 3 composite. The specific surface area of the composite reached 72.07 m2/g. The sensing performance of the SnO 2 , Pr-SnO 2 , In 2 O 3 , SnO 2 /In 2 O 3 , and Pr-SnO 2 /In 2 O 3 sensors to ethanol gas were systematically investigated. Among these sensors, at the optimal working temperature, the Pr-SnO 2 /In 2 O 3 sensor displayed the best sensing performance with a response value of 75 towards 50 ppm ethanol, and further exhibited good linearity coefficient, selectivity, reproducibility, and long-term stability. • Pr-SnO 2 /In 2 O 3 composite with hollow microtube was prepared via step-by-step method. • The composite combined rare earth doping, heterojunction and special structure. • The composite exhibited superior sensing properties to ethanol with response of 75 to 50 ppm. • The mechanism is explained by comparing the sensing performance of each component unit. [ABSTRACT FROM AUTHOR]

Cu 2-x Se has been known as an ideal thermoelectric material for application in the middle-high temperature range due to the outstanding electric transmission conductivity and relatively low lattice thermal conductivity. However, its performance is significantly constrained by its high thermal conductivity and thermal stability issues, as well as its difficulty in element doping because of the influence of atomic size and atomic solid solubility. Here, we prominently reduced the thermal conductivity of Cu 2-x Se by addition different amounts of WS 2 to the Cu 2-x Se matrix, and successfully improved the power factor of the material because of the reduction of high Cu defects to coordinate the three mutually coupled parameters. The zT value of the WS 2 -doping Cu 2-x Se sample was eventually enhanced by 56% compared with pristine Cu 2-x Se, and up to ca. 1 at 823 K. Further, we found that the symmetry of the Cu 2-x Se crystal had not been destroyed undergoing the doping of WS 2 into its crystal lattice, and the doped sample showed good thermal stability when cycle test was carried out twice between 315 K and 823 K. Cu 2-x Se were prepared by colloidal synthesis, and it's thermal conductivity was reduced by doping with different amounts of WS 2 into the Cu 2-x Se matrix, and the power factor of the doping material was improved through the reduction of high Cu defects to coordinate the three mutually coupled parameters. The ZT value of the WS 2 -doping Cu 2-x Se sample was eventually enhanced by 56% compared with pristine Cu 2-x Se, and up to ca. 1 at 823 K. [Display omitted] • The samples of WS 2 -doping Cu 2-x Se were prepared. • WS 2 -doping Cu 2-x Se had low thermal conductivity and high power factor through the reduction of high carrier concentration. • The zT value of the WS 2 -doping Cu 2-x Se sample was eventually enhanced by 56% compared with pristine Cu 2-x Se, and up to ca. 1 at 823 K. [ABSTRACT FROM AUTHOR]

Efficient and novel cobalt doped MnO 2 nanowires decorated with Graphene oxide was successfully synthesized with hydrothermal method and ultrasonic process. The nanocomposite phase was confirmed by XRD and XPS data. TEM and HRTEM analysis showed the good dispersion of MnO 2 nanowires on graphene oxide sheets. Benefiting from the synergistic effect between cobalt-doped MnO 2 nanowires and graphene oxide, the electrode material showed a satisfactory electrochemical performance with high specific capacitance of 397 F g−1 at 0.5 A g−1, high rate capability (328 F g−1 at 20 A g−1), and excellent capacitance retention only 2.5% decay after 4000 cycles at 10 A g−1 current density. As application for asymmetric supercapacitor device, the Cobalt doped MnO 2 decorated with graphene oxide (MCo(0.25)/GO) electrode achieved a wide potential window up to 2.3 V with a high energy density of 35.3 Wh·kg−1 at power density of 590 W kg−1. Moreover, an energy density value of 25.8 Wh·kg−1 is maintained at high power density (5.6 kW kg−1). Therefore, the prepared MCo(0.25)/GO nanocomposite, with outstanding electrochemical performance, is considered as suitable and great potential application for supercapacitor device in the next generation. Image 1 • MCo(0.25)/GO nanocomposite was prepared by hydrothermal and ultrasonic way. • The nanocomposite exhibited a high specific capacitance and high rate capability. • An energy density of 35.3 Wh·Kg−1 was achieved at a potential window of 2.3 V. [ABSTRACT FROM AUTHOR]

Abstract This study was about the simple method for the rapid colorimetric and visual detection of glucose molecules in water medium. Silver nanoparticles were spread on the chitosan surface (CS/Ag NCs) and it was characterized by UV–visible spectroscopy, fourier transform infrared spectroscopy (FTIR), X-ray diffraction spectroscopy (XRD), scanning electron microscope (SEM) and transmission electron microscope (TEM). The CS/Ag NCs displayed a strong surface plasmon resonance band at 429 nm which disappears in the addition of accelerative concentrations of glucose molecules and it was attended by color alteration from yellow to colorless. The interaction of glucose molecules on the CS/Ag NCs was displayed through TEM technique. Glucose molecules was detected not only by naked eyes (from yellow to purple grey) but also by UV–vis spectrophotometer in the concentration range between 0 and 100 μM, with limit detection of 5 μM and a good linear relationship of R2 value = 0.99. The proposed paper was used for the application of the detection of glucose molecules in water sample with adequate outcome. This CS/Ag NCs was very simple and low cost system without using any other enzymatic catalyst and organic chromogenic agents for glucose molecules detection. Highlights • Synthesis of CS/Ag NCs using simple method of heating at 90 °C for 6 h • Synthesized CS/Ag NCs were characterized using FTIR, XRD, SEM and TEM. • Addition of glucose molecules on the surface of CS/Ag NCs was imaged using TEM analysis. • To develop a colorimetric detection of glucose molecules between 5 and 100 μM concentration using CS/Ag NCs [ABSTRACT FROM AUTHOR]

Highlights • A novel, enhanced photoelectrochemical aptasensing was constructed for MUC1 detection. • CdS:Eu was first time prepared with successive ionic layer adsorption and reaction technique (SILAR). • CdS:Eu was first time applied to photoelectrochemical aptasensing. • FTO/TiO 2 /CdS:Eu composite electrode could evidently promote the photocurrent intensity. • The proposed photoelectrochemical protocol presented ultrahigh sensitivity, reproducibility, specificity and stability. Abstract A novel ultrasensitive photoelectrochemical aptasensing was developed to detect mucin 1 (MUC1) based on TiO 2 /CdS:Eu nanocomposite. The TiO 2 /CdS:Eu nanocomposite modified fluorine-doped tin oxide (FTO) electrode was prepared by successive ionic layer adsorption and reaction technique (SILAR) and then was employed as matrix for immobilization of SH-DNA (DNA1). After 6-mercaptohexanol (MCH) blocked unbound sites of the electrode surface, the MUC1 aptamer(DNA2) was introduced, allowing MUC1 aptamer to hybridize with DNA1. Subsequently, CdS-COOH QDs as signal amplification elements were successively labeled on the terminal of MUC1 aptamer. In this case, the target MUC1 detection was based upon the photocurrent change originated from quantities change of the signal amplification elements CdS. In the presence of MUC1, the MUC1 aptamer was specifically bound with MUC1, and meanwhile MUC1/DNA2/CdS was released from the electrode surface, resulting in significantly decreased photocurrent intensity. The novel ultrasensitive photoelectrochemical aptasensing presented a highly selective, sensitive and reproductive detection of MUC1 from 1 nM to 5 μM with a lower detection limit of 0.3 nM. At the same time, it also provided a good specificity, reproducibility, stability and promising strategy to detect a variety of other protein targets for early clinical diagnosis of different diseases. [ABSTRACT FROM AUTHOR]

A novel highly electrochemiluminescence (ECL) metal-organic frameworks (MOFs) have been successfully synthesized by combining CdSe quantum dots (QDs) and MIL-101 in one step by facile hydrothermal method. The as-prepared MIL-101-CdSe nanocomposites combine a high ECL activity and sensing selectivity derived from CdSe and the highly selective adsorption and efficient accumulation performance of MOFs. The selective accumulation effect of MOFs can greatly amplify the sensing signal and specificity of the ECL probe. The resulting nanocomposites were applied to develop an ultrasensitive ECL immunosensor for detection of carcinoembryonic antigen (CEA). This ECL immunosensor has a sensitive response to CEA in a linear range of 10 −12 mg mL −1 –10 −4 mg mL −1 with a detection limit of 0.33 fg mL −1 . The developed ECL immunosensor shows high sensitivity, good stability, specificity, and excellent reproducibility, and can be used for detection of real samples, which providing potential application in clinical detection. [ABSTRACT FROM AUTHOR]

The choice of an activator and activation method is crucial to the preparation of high-quality activated carbon. Herein, inspired by a foaming strategy, we selected KMnO 4 as activator, and hierarchical porous framework carbon material was prepared via lily powder being fully foamed and activated in the KMnO 4 hot solution. The Lily-derived Porous Carbon Material (LPCM) possesses the characteristics of in-situ co-doping of N and O. The maximum specific surface area of the obtained sample was 1852.5 m2g-1, and the corresponding total pore volume was 1.11 cm3g-1. Due to the interconnected hierarchical pore network structure and rich O (13.16 at%) & N (3.31 at%) contents, at 600 °C, the specific capacitance of the LPCM was 352 F g−1 at 0.5 A g1 and the cycling reliability was 100% after 10,000 charges and discharges. In addition, the voltage window of All-solid-state Symmetric Flexible Supercapacitor (ASFS) fabricated with PVA-KOH gel electrolyte was 1.4 V. And the fabricated ASFS device had energy density of 23.82 Wh kg−1 at 700 W kg−1. At the same time, two ASFSs in series could light up a small red bulb and maintained for more than 6 min. N, O co-doped porous activated carbon material was prepared by KMnO 4 as a foaming agent and activation reagent. The porous carbon material prepared exhibited superior specific capacitance (352 F g−1 at 0.5 A g−1) and cycle properties (100% after 10,000 charges and discharges). The voltage window was expanded to 1.4 V by PVA-KOH as a solid electrolyte, and had a large energy density (23.82 Wh kg−1) and power density (at 700 W kg−1). Two ASFSs in series could light up a small red bulb and maintained for more than 6 min. [Display omitted] • N/O co-doped porous carbon was prepared from Lily as biomass carbon materials. • KMnO 4 was used as an activator and foaming reagent for high-starch lily. • The porous carbon exhibited superior specific capacitance 352 F g−1 at 0.5 A g−1. • The porous carbon displayed 100% cycle stability after 10,000 charges and discharges. • The voltage window was expanded to 1.4 V by PVA-KOH as a solid electrolyte. [ABSTRACT FROM AUTHOR]

Precious metals doping can greatly change the gas sensing performance of semiconductor metal oxide. Herein, the Au-doped In 2 O 3 nanoparticles (NPs) were prepared via a combination solvothermal and liquid-phase reduction method, and the obtained nanoparticles were characterized by various techniques. The results indicated that Au nanocrystals with a diameter ca. 5 nm were uniformly distributed on the surface of the irregular In 2 O 3 NPs. Importantly, compared with undoped In 2 O 3 , the specific surface area of all the Au-doped In 2 O 3 NPs increased. And all the Au-doped In 2 O 3 sensors greatly improved the gas sensing performance towards ethanol. The optimal operating temperature reduced from 240 °C for undoped In 2 O 3 to 200 °C for Au-doped In 2 O 3. Of them, the 4 wt% Au-doped In 2 O 3 sensor displayed highly response (106 towards ethanol at 100 ppm) at the optimal operating temperature, good linear coefficient, high reproducibility, and long-term stability towards ethanol. Moreover, through the detection of seven gases including ethanol, such as methanol, acetone, benzene, formaldehyde, isopropanol, and nitrogen dioxide， we found that the fabricated sensor based on 4 wt% Au-doped In 2 O 3 had good selectivity towards ethanol. Finally, the mechanism of the excellent performance of the 4 wt% Au-doped In 2 O 3 sensor for ethanol was explained. • The Au-doped In 2 O 3 NPs were synthesized via a combination route. • The gas sensors based on Au-doped In 2 O 3 NPs were fabricated. • The optimal operating temperature reduced from 240 °C to 200 °C for Au-doped In 2 O 3. • The 4 wt% Au-doped In 2 O 3 sensor displayed high response (106 at 100 ppm) for ethanol. [ABSTRACT FROM AUTHOR]

Highlights: [•] A mild synthetic process. [•] Ag@C@Ag nanospheres with novel trilaminar core-shell structure. [•] Nonenzymatic sensor modified by Ag@C@Ag nanospheres. [•] Good performance to H2O2 detection. [ABSTRACT FROM AUTHOR]

Highlights: [•] Mnq2 nanobelts have been synthesized by a facile sonochemical route. [•] The experimental conditions play an important part in the morphology of the final products. [•] The as-prepared Mnq2 sample exhibited excellent ECL behavior. [ABSTRACT FROM AUTHOR]

Abstract: A novel graphene oxide nanosheets/polyaniline nanowires/CdSe quantum dots (GO/PANi/CdSe) nanocomposites are successfully synthesized and use as ECL immunosensor for detection of human interleukin-6 (IL-6). The as-prepared GO/PANi/CdSe nanocomposites show excellent biocompatibility, dispersity and solubility. Electrochemiluminescence (ECL) of CdSe quantudm dots (QDs) was greatly enhanced by combining with GO/PANi nanocomposites. Herein, this GO/PANi/CdSe nanocomposite was applied to develop an ultrasensitive ECL immunosensor for detection of IL-6. The ECL immunosensor has a sensitive response to IL-6 in a linear range of 0.0005–10ngmL−1. The prepared ECL immunosensor exhibits high specificity, long-term stability and excellent reproducibility with a detection limit of 0.17pgmL−1. [Copyright &y& Elsevier]

Abstract: Well-defined octahedral Znq2 has been synthesized via a facile solvothermal route. Field-emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM) images show that the as-prepared product has an octahedral structure with an edge length of 2μm. The reaction parameters, such as solvent, reaction time and temperature, play an important part in the morphology of the final product. A possible formation mechanism for octahedral Znq2 is proposed. The as-prepared octahedral Znq2 exhibits excellent electrogenerated chemiluminescence (ECL) behaviour. [Copyright &y& Elsevier]

Abstract: 8-Hydroxyquinoline cadmium (Cdq2) nanobelts with width of 100–200nm and lengths of 0.5–2μm have been successfully synthesized through a facile solvothermal method at 120°C for 24h. The composition, morphology and structure of the as-prepared products were confirmed by X-ray powder diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Experiment results indicated that the concentration of ethanol played an important effect in the morphology of the final products. Moreover, the electrogenerated chemiluminescence (ECL) properties of the Cdq2 sample with different morphologies were investigated. The ECL spectra show that the Cdq2 nanobelts exhibited excellent electrogenerated chemiluminescence (ECL) behavior. [Copyright &y& Elsevier]