scholarly journals Novel Graphene/In2O3 Nanocubes Preparation and Selective Electrochemical Detection for L-Lysine of Camellia nitidissima Chi

Materials ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1999
Author(s):  
Jinsheng Cheng ◽  
Sheng Zhong ◽  
Weihong Wan ◽  
Xiaoyuan Chen ◽  
Ali Chen ◽  
...  

In this work, novel graphene/In2O3 (GR/In2O3) nanocubes were prepared via one-pot solvothermal treatment, reduction reaction, and successive annealing technology at 600 °C step by step. Interestingly, In2O3 with featured cubic morphology was observed to grow on multi-layered graphene nanosheets, forming novel GR/In2O3 nanocubes. The resulting nanocomposites were characterized using transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction spectroscopy (XRD), etc. Further investigations demonstrated that a selective electrochemical sensor based on the prepared GR/In2O3 nanocubes can be achieved. By using the prepared GR/In2O3-based electrochemical sensor, the enantioselective and chem-selective performance, as well as the optimal conditions for L-Lysine detection in Camellia nitidissima Chi, were evaluated. The experimental results revealed that the GR/In2O3 nanocube-based electrochemical sensor showed good chiral recognition features for L-lysine in Camellia nitidissima Chi with a linear range of 0.23–30 μmol·L−1, together with selectivity and anti-interference properties for other different amino acids in Camellia nitidissima Chi.

2019 ◽  
Vol 43 (3-4) ◽  
pp. 135-139
Author(s):  
Pegah Farokhian ◽  
Manouchehr Mamaghani ◽  
Nosrat Ollah Mahmoodi ◽  
Khalil Tabatabaeian ◽  
Abdollah Fallah Shojaie

An efficient protocol for the facile synthesis of a series of pyrido[2,3- d]pyrimidine derivatives has been developed applying Fe3O4–ZnO–NH2–PW12O40 nanocatalyst in water. This novel method has the benefits of operational simplicity, green aspects by avoiding toxic solvents and high to excellent yields of products. Fe3O4–ZnO–NH2–PW12O40 was synthesized and characterized by Fourier transform infrared, X-ray diffraction, vibrating sample magnetometer, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and transmission electron microscopy analyses. The nanocatalyst is readily isolated and recovered from the reaction mixture by an external magnet.


Nanomaterials ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 999
Author(s):  
Yi-An Chen ◽  
Kuo-Hsien Chou ◽  
Yi-Yang Kuo ◽  
Cheng-Ye Wu ◽  
Po-Wen Hsiao ◽  
...  

To the best of our knowledge, this report presents, for the first time, the schematic of the possible chemical reaction for a one-pot synthesis of Zn0.5Cd0.5Se alloy quantum dots (QDs) in the presence of low/high oleylamine (OLA) contents. For high OLA contents, high-resolution transmission electron microscopy (HRTEM) results showed that the average size of Zn0.5Cd0.5Se increases significantly from 4 to 9 nm with an increasing OLA content from 4 to 10 mL. First, [Zn(OAc)2]–OLA complex can be formed by a reaction between Zn(OAc)2 and OLA. Then, Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD) data confirmed that ZnO is formed by thermal decomposition of the [Zn(OAc)2]–OLA complex. The results indicated that ZnO grew on the Zn0.5Cd0.5Se surface, thus increasing the particle size. For low OLA contents, HRTEM images were used to estimate the average sizes of the Zn0.5Cd0.5Se alloy QDs, which were approximately 8, 6, and 4 nm with OLA loadings of 0, 2, and 4 mL, respectively. We found that Zn(OAc)2 and OLA could form a [Zn(OAc)2]–OLA complex, which inhibited the growth of the Zn0.5Cd0.5Se alloy QDs, due to the decreasing reaction between Zn(oleic acid)2 and Se2−, which led to a decrease in particle size.


2014 ◽  
Vol 2014 ◽  
pp. 1-4 ◽  
Author(s):  
Fei Long ◽  
Shuyi Mo ◽  
Yan Zeng ◽  
Shangsen Chi ◽  
Zhengguang Zou

Flower-like Cu2ZnSnS4(CZTS) nanoflakes were synthesized by a facile and fast one-pot solution reaction using copper(II) acetate monohydrate, zinc acetate dihydrate, tin(IV) chloride pentahydrate, and thiourea as starting materials. The as-synthesized samples were characterized by X-ray diffraction (XRD), Raman scattering analysis, field emission scanning electron microscopy (FESEM) equipped with an energy dispersion X-ray spectrometer (EDS), transmission electron microscopy (TEM), and UV-Vis absorption spectra. The XRD patterns shown that the as-synthesized particles were kesterite CZTS and Raman scattering analysis and EDS confirmed that kesterite CZTS was the only phase of product. The results of FESEM and TEM show that the as-synthesized particles were flower-like morphology with the average size of 1~2 μm which are composed of 50 nm thick nanoflakes. UV-Vis absorption spectrum revealed CZTS nanoflakes with a direct band gap of 1.52 eV.


BioResources ◽  
2019 ◽  
Vol 14 (3) ◽  
pp. 6114-6133
Author(s):  
Chunxiang Lin ◽  
Yushi Liu ◽  
Qiaoquan Su ◽  
Yifan Liu ◽  
Yuancai Lv ◽  
...  

An effective cellulose/MoS2 (Ce/MoS2) composite was synthesized via a one-pot microwave-assisted ionic liquid method for the photocatalytic reduction of toxic Cr(VI). Effects of ionic liquids (ILs) on the MoS2 nanostructure were considered, and the obtained composite was characterized by x-ray diffraction (XRD), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectrometry (XPS), and electrochemical impedance spectroscopy (EIS). The results indicated that the MoS2 nanoplates were anchored and dispersed on the surface of the cellulose. Compared with the pristine MoS2, the support of the cellulose greatly enhanced the photocatalytic reduction efficiency of Cr(VI) ions in solution, from 65.9% to nearly 100%. The reduction mechanism was considered, and the results implied that the simultaneous reduction of Cr(VI) during the initial dark adsorption process was observed due to the effect of citric acid as a hole scavenger. Finally, regeneration tests revealed that the Ce/MoS2 composite could be recycled and reused.


2014 ◽  
Vol 609-610 ◽  
pp. 76-81 ◽  
Author(s):  
Ling Wei Hu ◽  
Hua Tian ◽  
Yu Xia Zhang ◽  
Kun Lu ◽  
Ai Hua Jing

ZnO/graphene composites has been synthesized using a one-pot hydrothermal method at moderate temperature of 90°C. Hydrothermal growth was done in an aqueous solution consisting of 20 mL graphene oxide (GO) solution (0.25 mg/mL) with equimolar of zinc acetate [ZAc, Zn (CH3COO)2·2H2 and hexamethylenetetramine (HMTA, C6H12N4). The as-synthesized composites was characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and Raman spectroscopy. The results of the characterization indicate that GO was reduced to graphene in the growth process, while ZnO in the form of quantum dots (QDs) or nanoparticles embedded in the graphene sheet. The composites synthesized by this method will have potential applications in bioimaging, gas sensing, optoelectrical materials and devices. The photoluminescence (PL) of the conposites was also investigated.


NANO ◽  
2014 ◽  
Vol 09 (07) ◽  
pp. 1450084 ◽  
Author(s):  
HAIQIU LIU ◽  
YUJIAN JIN ◽  
NA LI ◽  
LILI WANG ◽  
SUNQI LOU ◽  
...  

Three-dimensional (3D) γ- MnOOH networks are successfully prepared by one-pot solvothermal method without using any catalyst. The samples are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HRTEM). It is found that the amounts of urea and H 2 O 2 added, reaction temperature and time have important influences on the samples. It is interesting that the 3D networks are formed from the oriented attachment (OA) of Mn 3 O 4 octahedrons; and that the phase transformation from Mn 3 O 4 to γ- MnOOH occurs via the protonation of Mn 3 O 4. This study is expected to offer a facile approach to the syntheses of new, intricate nanostructures.


2013 ◽  
Vol 774-776 ◽  
pp. 677-681
Author(s):  
Han Tao Liao ◽  
You Rong Wang ◽  
Jia Wang ◽  
Xiao Fang Qian ◽  
Si Qing Cheng

The particle size and morphology have a strong influence on the electrochemical performance of FeS2electrodes. In this paper, a simple one-pot solvothermal method is reported for the synthesis of macroporous pyrite nanotubes for the first time. The phase composition, morphology and structure of the as-obtained products were studied by the energy dispersive spectroscopy (EDS), scanning electron microscopy, (high-resolution) transmission electron microscopy, X-ray diffraction. The electrochemical properties of the FeS2samples were also investigated. The results demonstrated that the macroporous pyrite nanotubes delivered a higher initial discharge capacity of 925.2 mAh g-1and had good capacity retention.


2020 ◽  
Vol 20 (5) ◽  
pp. 2698-2704 ◽  
Author(s):  
Zhen Zhu ◽  
Yan-Wei Han ◽  
Chia-Ying Hsieh ◽  
Suh-Jen Jane Tsai ◽  
An-Kai Syu ◽  
...  

In the present study, a novel AgOx/BiPO4 sensor was successfully prepared and used for detecting trans-resveratrol. Prepared samples were characterized using methods including X-ray diffraction, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy. The results demonstrate that the AgOx/BiPO4 is composed of AgO, Ag2O, and BiPO4. In addition, a cyclic voltammetry method was used to measure resveratrol concentration using the electrochemical sensor based on AgOx/BiPO4. AgOx/BiPO4 presents a well-defined voltammetric peak at approximately +460 mV versus Ag/AgCl in phosphate-buffered saline solution. In addition, the sensor exhibits a detection limit of 1.0×10−7 M, and the wide dynamic concentration ranges from 2.0×10−7 to 12.5×10−6 M. Stability and interference tests were performed for 20 days. A possible mechanism for AgOx/BiPO4 detection of trans-resveratrol detection is proposed.


Molecules ◽  
2019 ◽  
Vol 24 (18) ◽  
pp. 3411 ◽  
Author(s):  
Dongqing Xu ◽  
Bingbing Hou ◽  
Lisheng Qian ◽  
Xueji Zhang ◽  
Guodong Liu

The authors report a non-enzymatic electrochemical sensor based on a sliver nanoparticle-decorated carbon nanotube (AgNPs-MWCNT). Highly-dispersed AgNPs were loaded on the MWCNT surface though a simple and facile two-step method. The morphology, components, and the size of the AgNPs-MWCNT nanocomposite were characterized by transmission electron microscopy, X-ray diffraction, and ICP analysis. Benefitting from the synergistic effect between the AgNPs and MWCNT, the AgNPs-MWCNT nanocomposite exhibited high electrocatalytic activity for H2O2; the AgNPs-MWCNT electrochemical sensor was prepared by coating the AgNPs-MWCNT nanocomposite on a glassy carbon electrode, and it showed a fast and sensitive response to H2O2 with a linear range of 1 to 1000 μM. The detection limit was 0.38 μM (S/N = 3). The sensor was applied to detect H2O2 in spiked human blood serum samples with satisfactory results.


2010 ◽  
Vol 663-665 ◽  
pp. 1150-1153
Author(s):  
Han Mei Hu ◽  
Chong Hai Deng

The porous hierarchical spherical CuInS2 microsturctures have been successfully fabricated through one-pot solvothermal technique. The crystal structure and morphology of the as-synthesized products are characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM). The results reveal that the shells of CuInS2 microspheres are composed of nanosheets or nanoparticles. The possible formation mechanism of CuInS2 porous microspheres is simply discussed.


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