scholarly journals Highly sensitive, non-enzymatic and precious metal-free electrochemical glucose sensor based on Ni-Cu/TiO2 modified glassy carbon electrode

2018 ◽  
Vol 83 (6) ◽  
pp. 733-744 ◽  
Author(s):  
Abdul Raziq ◽  
Muhammad Tariq ◽  
Riaz Hussain ◽  
Muhammad Mehmood ◽  
Inam Ullah ◽  
...  
Keyword(s):  
Glassy Carbon ◽  
Glucose Sensor ◽  
Modified Electrodes ◽  
Xrd Analysis ◽  
Catalytic Performance ◽  
Glucose Sensing ◽  
Basic Medium ◽  
X Ray ◽  
Highly Sensitive ◽  
One Step

Herein, a facile one step synthesis of Ni?Cu supported on TiO2 alloy nanoparticles through the polyol method, which reflect high catalytic performance in enzymeless electrochemical glucose sensing and applied onto glassy carbon, is reported. The morphology imaging and physical properties of the Ni?Cu/TiO2 nanocomposite were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) analysis, and energy dispersive X-ray spectroscopy (EDS). The electrochemical studies/characterizations of glucose oxidation were realised in a basic medium and the new sensor was found to be a better electrochemical glucose sensor than Ni/TiO2/Ti and CuO/TiO2/Ti modified electrodes. The fabricated sensor was highly sensitive (719.9 ?A mM-1 cm-2), had a wide linear range (from 0.1 to 6 mM), selective and tolerant towards endogenous species, such as ascorbic acid, uric acid, acetaminophen and sodium chloride.

scholarly journals 3D Modeling of Silver Doped ZrO2 Coupled Graphene-Based Mesoporous Silica Quaternary Nanocomposite for a Nonenzymatic Glucose Sensing Effects

Nanomaterials ◽  
2022 ◽  
Vol 12 (2) ◽  
pp. 193
Author(s):  
Kamrun Nahar Fatema ◽  
Chang-Sung Lim ◽  
Yin Liu ◽  
Kwang-Youn Cho ◽  
Chong-Hun Jung ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Mesoporous Silica ◽  
Photoelectron Spectroscopy ◽  
Glucose Sensor ◽  
Diffuse Reflectance Spectroscopy ◽  
Active Material ◽  
Glucose Sensing ◽  
X Ray ◽  
Transmission Electron

We described the novel nanocomposite of silver doped ZrO2 combined graphene-based mesoporous silica (ZrO2-Ag-G-SiO2,) in bases of low-cost and self-assembly strategy. Synthesized ZrO2-Ag-G-SiO2 were characterized through X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectrometry (EDX), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), Raman spectroscopy, Nitrogen adsorption-desorption isotherms, X-ray photoelectron spectroscopy (XPS), and Diffuse Reflectance Spectroscopy (DRS). The ZrO2-Ag-G-SiO2 as an enzyme-free glucose sensor active material toward coordinate electro-oxidation of glucose was considered through cyclic voltammetry in significant electrolytes, such as phosphate buffer (PBS) at pH 7.4 and commercial urine. Utilizing ZrO2-Ag-G-SiO2, glucose detecting may well be finished with effective electrocatalytic performance toward organically important concentrations with the current reaction of 9.0 × 10−3 mAcm−2 and 0.05 mmol/L at the lowest potential of +0.2 V, thus fulfilling the elemental prerequisites for glucose detecting within the urine. Likewise, the ZrO2-Ag-G-SiO2 electrode can be worked for glucose detecting within the interferometer substances (e.g., ascorbic corrosive, lactose, fructose, and starch) in urine at proper pH conditions. Our results highlight the potential usages for qualitative and quantitative electrochemical investigation of glucose through the ZrO2-Ag-G-SiO2 sensor for glucose detecting within the urine concentration.

Hierarchical Nanostructured ZnO-CuO Nanocomposite and its Photocatalytic Activity

2015 ◽  
Vol 35 ◽  
pp. 21-26 ◽  
Author(s):  
Susmita Das ◽  
Vimal Chandra Srivastava
Keyword(s):  
Photocatalytic Activity ◽  
Pure Copper ◽  
Ultra Violet ◽  
Xrd Analysis ◽  
Sem Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ultra Violet Radiation ◽  
One Step ◽  
Uv Visible

Metal oxide nanocomposite (ZnO-CuO) was successfully synthesized by one step homogeneous coprecipitation method and further characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron micrograph (SEM), X-ray diffraction analysis (XRD) and UV-visible diffuse reflectance spectra. XRD analysis exhibited presence of pure copper oxide and zinc oxide within the nanocomposite. SEM analysis indicated that the ZnO-CuO nanocomposite was consisted of flower shaped ZnO along with leaf shaped CuO. Photocatalytic activity of nanocomposite was evaluated in terms of degradation of methylene blue (MB) dye solution under ultra-violet radiation. Results showed that the photocatalytic efficiency of ZnO-CuO nanocomposite was higher than its individual pure oxides (ZnO or CuO).

Effect of vacuum annealing on the properties of one step thermally evaporated Sb2S3 thin films for photovoltaic applications

2021 ◽  
Author(s):  
Emna Gnenna ◽  
Naoufel Khemiri ◽  
Minghua Kong ◽  
Maria Isabel Alonso ◽  
Mounir Kanzari
Keyword(s):  
Thin Films ◽  
Annealing Temperature ◽  
Vacuum Annealing ◽  
Xrd Analysis ◽  
Band Gap Energy ◽  
Chemical Compositions ◽  
Optical Parameters ◽  
X Ray ◽  
Vis Spectroscopy ◽  
One Step

Sb2S3 powder was successfully synthesized by solid state reaction technique using high-purity elemental antimony and sulfur. Sb2S3 thin films were deposited on unheated glass substrates by one step thermal evaporation and annealed under vacuum atmosphere for 2 hours at different temperatures 150, 200 and 250 °C. Different characterization techniques were used to better understand the behavior of the Sb2S3 material. X-ray diffraction (XRD) and Raman spectroscopy confirmed the formation of pure Sb2S3 powder with lattice parameters a = 11.07 Å, b = 11.08 Å and c = 3.81 Å. The effect of vacuum annealing temperature on the properties of the films was studied. XRD analysis revealed that as-deposited and annealed films at 150ºC were amorphous in nature whereas those annealed at T ≥ 200°C were polycrystalline with a preferred orientation along (201) plane. The crystallite size of the polycrystalline films showed a decrease from 75.8 to 62.9 nm with the increase of the annealing temperature from 200 to 250 °C. The Raman analysis showed several peaks corresponding to the stibnite Sb2S3 phase. The surface morphology of the films was examined by atomic force microscopy (AFM). The surface roughness decreases slightly as the transformation from the amorphous to the crystalline phase occurs. The chemical compositions of Sb2S3 films were analyzed by energy dispersive X-ray spectroscopy (EDS), revealing that all films were Sb-rich. The optical parameters were estimated from the transmittance and reflectance spectra recorded by UV-Vis spectroscopy. A reduction in the direct band gap energy from 2.12 to 1.70 eV with the increase of annealing temperature was also found.

scholarly journals Preparation and Photocatalytic Performances of WO3/TiO2 Composite Nanofibers

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Xiuping Han ◽  
Binghua Yao ◽  
Keying Li ◽  
Wenjing Zhu ◽  
Xuyuan Zhang
Keyword(s):  
Photoelectron Spectroscopy ◽  
Photocatalytic Oxidation ◽  
Composite Nanofibers ◽  
Photogenerated Electron ◽  
Xrd Analysis ◽  
Catalytic Performance ◽  
Active Species ◽  
X Ray ◽  
Bet Analysis ◽  
Electron Holes

The use of sunlight for photocatalytic oxidation is an ideal strategy, but it is limited by factors such as insufficient light absorption intensity of the photocatalyst and easy recombination of photogenerated electron holes. TiO2 is favored by researchers as an environment-friendly catalyst. In this paper, TiO2 is combined with WO3 to obtain a nanofiber with excellent catalytic performance under sunlight. The WO3/TiO2 composite nanofibers were synthesized by using the electrospinning method. The X-ray diffraction (XRD) analysis indicated that WO3 was successfully integrated onto the surface of TiO2. The photodegradation performance and photocurrent analysis of the prepared nanofibers showed that the addition of WO3 really improved the photocatalytic performance of TiO2 nanofibers, methylene blue (MB) degradation rate increased from 72% to 96%, and 5% was the optimal composite mole percentage of W to Ti. The scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), UV-Vis diffuse reflectance spectra (UV-Vis DRS), and Brunauer-Emmett-Teller (BET) analysis further characterized the properties of 5% WO3/TiO2 nanofibers. The H2 generation rate of 5% WO3/TiO2 nanofibers was 107.15 μmol·g−1·h−1, in comparison with that of TiO2 nanofibers (73.21 μmol·g−1·h−1) under the same condition. The 5% WO3/TiO2 produced ·OH under illumination, which played an important role in the MB degradation. Also, the enhanced photocatalytic mechanism was also proposed based on the detailed analysis of the band gap and the active species trapping experiment. The results indicated that the effective separation of Z-scheme photogenerated electron-hole pairs and transfer system constructed between TiO2 and WO3 endowed the excellent photocatalytic activity of 5% WO3/TiO2 nanofibers.

scholarly journals A facile method to fabricate AC/CuO for efficient removal of organic pollutants by adsorption and persulfate-based advanced oxidation processes

2020 ◽  
Author(s):  
Youlin Li ◽  
Yu Hu ◽  
Wenqiao You ◽  
Guangming Zhou ◽  
Guilong Peng
Keyword(s):  
Catalytic Performance ◽  
Catalytic Degradation ◽  
Maximum Adsorption Capacity ◽  
Efficient Removal ◽  
X Ray ◽  
One Step ◽  
Ft Ir ◽  
Degradation Reaction ◽  
The Relationship ◽  
Insight Into

Abstract Activated carbon/CuO (AC/CuO) composites was prepared through a facile one-step hydrothermal method and used as a bifunctional material for adsorption and catalysis degradation of bisphenol A (BPA). The composite was characterized by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and X-ray powder diffraction (XRD). The obtained AC/CuO exhibited excellent adsorption and catalytic performance. The maximum adsorption capacity of BPA on the AC/CuO was 319.03 mg/g according to the Langmuir fitting. At an initial BPA concentration of 20 mg/L, the BPA degradation efficiencies were maintained above 96% for 15 min by using 20 mg/L AC/CuO and 2 mM peroxymonosulfate (PMS). Moreover, the relationship between adsorption and catalytic degradation was also investigated. The results indicated that the pre-adsorption disfavored the degradation reaction. This work not only provides a novel preparation method for AC/CuO catalyst, but also gives a deeper insight into the mechanisms between adsorption and catalytic degradation.

Synthesis of Novel Pd Nanosponges for Non-Enzymatic Glucose Sensor

2020 ◽  
Vol 20 (12) ◽  
pp. 7333-7341
Author(s):  
Feng Chen ◽  
Jing-Hao Li ◽  
Yu-Chen Chi ◽  
Zhen-Hua Dan ◽  
Feng-Xiang Qin
Keyword(s):  
Glucose Sensor ◽  
High Sensitivity ◽  
Cost Effective ◽  
Active Surface ◽  
Glucose Sensing ◽  
Active Surface Area ◽  
Long Term Stability ◽  
High Uniformity ◽  
One Step ◽  
The Cost

A unique nanostructured electrocatalyst based on Palladium (Pd) nanosponge architecture is synthesized by one-step dealloying of the amorphous alloy precursor with low Pd concentration. The sponge-like nanostructure with hollow interiors enables sufficient contact between reactants andboth the interior and exterior surfaces. The results of cyclic voltammetry reveal that the as-prepared Pd nanosponge exhibits high sensitivity of 32 μA mM−1 cm−2 in a wide linear range (1–18 mM), and long-term stability toward glucose electro-oxidation. The Pd nanosponge also manifests detection limit as low as 2.0 μM (S/N = 3) and high selectivity for glucose sensing. The enhanced catalytic activity of the Pd nanosponge is attributed to the bimetallic synergistic effect and the large active surface area of the high-uniformity porous structure. The facile synthesis of the cost-effective Pd nanosponge with superior electrocatalytic performance makes it hold great potentials for biosensor and other catalysis applications.

scholarly journals Ferrocene-Containing Ionic Liquid Supported on Silica Nanospheres (SiO2@Imid-Cl@Fc) as a Mild and Efficient Heterogeneous Catalyst for the Synthesis of Pyrano[3,2-b]Pyran Derivatives Under Ultrasound Irradiation

2018 ◽  
Vol 42 (1) ◽  
pp. 7-12 ◽  
Author(s):  
Reza Teimuri-Mofrad ◽  
Somayeh Esmati ◽  
Masoumeh Rabiei ◽  
Mahdi Gholamhosseini-Nazari
Keyword(s):  
Ionic Liquid ◽  
Reaction Times ◽  
Aromatic Aldehydes ◽  
Ultrasound Irradiation ◽  
Xrd Analysis ◽  
Catalytic Performance ◽  
Significant Loss ◽  
One Pot ◽  
X Ray ◽  
Three Component Reaction

A novel heterogeneous silica nanosphere-supported ferrocene-containing ionic liquid catalyst (SiO2@Imid-Cl@Fc) was designed and synthesised and was systematically characterised by Fourier transform infrared (FTIR) spectroscopy, field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray (EDX) and X-ray diffraction (XRD) analysis. The catalytic activity of the SiO2@Imid-Cl@Fc catalyst was tested in a one-pot, three-component reaction of malononitrile and kojic acid with 15 aromatic aldehydes at room temperature under ultrasound irradiation. The products were pyrano[3,2-b]pyran derivatives, four of which are new. The catalyst exhibited good catalytic performance over short reaction times (15–20 min) and could be recycled at least five times without significant loss of activity.

scholarly journals Effect of Cobalt on Nickel Oxide Toward Reduction Behaviour in Hydrogen and Carbon Monoxide Atmosphere

2020 ◽  
Vol 1010 ◽  
pp. 373-378
Author(s):  
Norliza Dzakaria ◽  
Maratun Najiha Abu Tahari ◽  
Salma Samidin ◽  
Tengku Shafazila Tengku Saharuddin ◽  
Fairous Salleh ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
Nickel Oxide ◽  
Reduction Process ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Reduction Behaviour ◽  
One Step ◽  
Temperature Programmed ◽  
Co Doped

The reduction behaviour of cobalt doped with nickel oxide and undoped nickel oxide (NiO) by hydrogen (H2) in nitrogen (20%, v/v) and carbon monoxide (CO) in nitrogen (40%, v/v) atmospheres have been investigated by temperature programmed reduction (TPR). The phases formed of partially and completely reduced samples were characterized by X-ray diffraction spectroscopy (XRD). TPR results indicate that the reduction of Co doped and undoped nickel oxide in both reductants proceed in one step reduction (NiO → Ni) without intermediate. TPR results also suggested that by adding Co metal into NiO, the reduction to metallic Ni by both reductant gaseous give different intensity of the peak. The reduction process of Co and undoped NiO become faster when H2 was used as a reductant. Furthermore, in H2 atmosphere, Co-NiO give complete reduction to metallic Ni at 700 °C. Meanwhile, XRD analysis indicated that NiO without Co composed better crystallite phases of NiO with higher intensity.

scholarly journals Zn/F-doped tin oxide nanoparticles synthesized by laser pyrolysis: structural and optical properties

2019 ◽  
Vol 10 ◽  
pp. 9-21 ◽  
Author(s):  
Florian Dumitrache ◽  
Iuliana P Morjan ◽  
Elena Dutu ◽  
Ion Morjan ◽  
Claudiu Teodor Fleaca ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Laser Energy ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Laser Pyrolysis ◽  
One Step ◽  
Diffraction Patterns ◽  
Tin Oxide Nanoparticles ◽  
Co Doped

Zn/F co-doped SnO2 nanoparticles with a mean diameter of less than 15 nm and a narrow size distribution were synthesized by a one-step laser pyrolysis technique using a reactive mixture containing tetramethyltin (SnMe4) and diethylzinc (ZnEt2) vapors, diluted Ar, O2 and SF6. Their structural, morphological, optical and electrical properties are reported in this work. The X-ray diffraction (XRD) analysis shows that the nanoparticles possess a tetragonal SnO2 crystalline structure. The main diffraction patterns of stannous fluoride (SnF2) were also identified and a reduction in intensity with increasing Zn percentage was evidenced. For the elemental composition estimation, energy dispersion X-ray spectroscopy (EDX) and X-ray photoelectron spectroscopy (XPS) measurements were performed. In general, both analyses showed that the Zn percentage increases with increasing ZnEt2 flow, accompanied at the same time by a decrease in the amount of F in the nanopowders when the same SF6 flow was employed. The Raman spectra of the nanoparticles show the influence of both Zn and F content and crystallite size. The fluorine presence is due to the catalytic partial decomposition of the SF6 laser energy transfer agent. In direct correlation with the increase in the Zn doping level, the bandgap of co-doped nanoparticles shifts to lower energy (from 3.55 to 2.88 eV for the highest Zn dopant concentration).

scholarly journals The three-dimensional flower-like Bi 2 WO 6 assisted by ethanolamine through a microwave method for efficient photocatalytic activity

2019 ◽  
Vol 6 (3) ◽  
pp. 181422
Author(s):  
Xingchen Liu ◽  
SuZhen Wang ◽  
Song Wang ◽  
Han Shi ◽  
Xiaolong Zhang ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Photoelectron Spectroscopy ◽  
Three Dimensional ◽  
Catalytic Performance ◽  
Microwave Method ◽  
Photocatalytic Efficiency ◽  
X Ray Diffraction ◽  
Structure Directing Agent ◽  
X Ray ◽  
One Step

The three-dimensional flower-like Bi 2 WO 6 was synthesized through a one-step microwave method (the reaction temperature was 434 K and the reaction took 10 min) with the assistance of ethanolamine (EA). The prepared samples were characterized by X-ray diffraction, scanning electron microscopy, Fourier-transform infrared spectroscopy, ultraviolet–visible spectroscopy, PL, X-ray photoelectron spectroscopy and Brunauer–Emmett–Teller analysis. Methyl orange was used as target pollutant to evaluate the photocatalysis property of samples. Furthermore, the influence of the mechanism of EA on the structure and catalytic performance of Bi 2 WO 6 was discussed. The detailed characterizations revealed that the three-dimensional flower-like Bi 2 WO 6 was successfully synthesized with the assistance of EA. The results confirmed that EA significantly influenced the morphology of Bi 2 WO 6 products. The addition of EA can effectively alter the pressure of the reaction and improve the crystal phase and structure of Bi 2 WO 6 photocatalysts, enhancing the photocatalytic activity of samples and improving the photocatalytic efficiency. EA can serve as an assembling agent and structure-directing agent resulting in the formation of flower-like architectures. With the increase of the amount of EA, the as-prepared Bi 2 WO 6 sample gradually forms a flower-like structure, leading to a shorter time of light holes migrating to the surface of the catalyst. It makes the compound rate significantly decreased, and improves the photocatalytic efficiency of the sample.

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