An Efficient Simple Hydrothermal Method to Synthesis FeS2 Microspheres and their Optical Property

2016 ◽  
Vol 847 ◽  
pp. 72-77
Author(s):  
Yu Xuan Liang ◽  
Peng Peng Bai ◽  
Shu Qi Zheng
Keyword(s):  
Photoelectron Spectroscopy ◽  
Low Cost ◽  
Wave Length ◽  
Functional Materials ◽  
Optical And Electrical Properties ◽  
X Ray Diffraction ◽  
Synthetic Sample ◽  
X Ray ◽  
New Type ◽  
Good Uniformity

Pyrite (FeS2) is an important semiconductor material which shows various excellent optical and electrical properties and extensive applied prospect as a new-type, photoelectrical functional materials. In this study, a low cost and efficient simple hydrothermal two-step synthetic method was given to obtain FeS2 microspheres with 2-3 μm in diameter. The obtained products were characterized with X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and ultraviolet and visible spectrophotometer (UV-Vis). XRD showed that the synthetic sample consisted of two crystal structures of FeS2, pyrite and marcasite. SEM observation indicated that FeS2 microspheres were well crystallized and had good uniformity. UV-Vis spectrum had a strong optical absorption in the region of 200-400 nm wave length. The reaction temperature had an impact on the size of FeS2 microspheres. A possible mechanism for the size of the FeS2 microspheres generated at high temperature is smaller than that at low temperature is discussed.

scholarly journals Nanosheets of CuCo2O4 As a High-Performance Electrocatalyst in Urea Oxidation

2019 ◽  
Vol 9 (4) ◽  
pp. 793 ◽  
Author(s):  
Camila Zequine ◽  
Fangzhou Wang ◽  
Xianglin Li ◽  
Deepa Guragain ◽  
S.R. Mishra ◽  
...  
Keyword(s):  
Fuel Cells ◽  
Photoelectron Spectroscopy ◽  
High Performance ◽  
Nickel Foam ◽  
Low Cost ◽  
Agricultural Waste ◽  
Bifunctional Catalyst ◽  
X Ray Diffraction ◽  
X Ray ◽  
Electroactive Material

The urea oxidation reaction (UOR) is a possible solution to solve the world’s energy crisis. Fuel cells have been used in the UOR to generate hydrogen with a lower potential compared to water splitting, decreasing the costs of energy production. Urea is abundantly present in agricultural waste and in industrial and human wastewater. Besides generating hydrogen, this reaction provides a pathway to eliminate urea, which is a hazard in the environment and to people’s health. In this study, nanosheets of CuCo2O4 grown on nickel foam were synthesized as an electrocatalyst for urea oxidation to generate hydrogen as a green fuel. The synthesized electrocatalyst was characterized using X-ray diffraction, scanning electron microscopy, and X-ray photoelectron spectroscopy. The electroactivity of CuCo2O4 towards the oxidation of urea in alkaline solution was evaluated using electrochemical measurements. Nanosheets of CuCo2O4 grown on nickel foam required the potential of 1.36 V in 1 M KOH with 0.33 M urea to deliver a current density of 10 mA/cm2. The CuCo2O4 electrode was electrochemically stable for over 15 h of continuous measurements. The high catalytic activities for the hydrogen evolution reaction make the CuCo2O4 electrode a bifunctional catalyst and a promising electroactive material for hydrogen production. The two-electrode electrolyzer demanded a potential of 1.45 V, which was 260 mV less than that for the urea-free counterpart. Our study suggests that the CuCo2O4 electrode can be a promising material as an efficient UOR catalyst for fuel cells to generate hydrogen at a low cost.

Low Cost Integrated Sensors Utilizing Patterned Nano-Structured Titania Arrays Fabricated Using a Simple Process

2004 ◽  
Vol 828 ◽  
Author(s):  
Zuruzi Abu Samah ◽  
Andrei Kolmakov ◽  
Martin Moskovits ◽  
Noel C. MacDonald
Keyword(s):  
Photoelectron Spectroscopy ◽  
Low Cost ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
Aqueous Hydrogen Peroxide ◽  
X Ray ◽  
Sensing Systems ◽  
Potential Applications ◽  
Nano Wires ◽  
Low Temperature Process

ABSTRACTUsing a novel low-temperature process, we demonstrate the facile integration of crack-free nanostructured titania (NST) as sensing elements in microsystems. Unlike conventional sol-gel methods, NST layers of interconnected nano-walls and nano-wires were formed by reacting Ti surfaces with aqueous hydrogen peroxide solution. Cracks were observed in NST layers formed on blanket Ti films but absent on arrays of patterned Ti pads below a threshold dimension. Analyses using TEM, high resolution SEM, X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) reveal that NST consists of anatase TiO2 nano-crystals. NST pads were found able to detect oxygen gas of a few ppm. NST pad arrays were integrated on rigid and flexible substrates with potential applications in low cost and wearable sensing systems.

scholarly journals Sorption of Molybdates and Tungstates on Functionalized Montmorillonites: Structural and Textural Features

Materials ◽  
2019 ◽  
Vol 12 (14) ◽  
pp. 2253 ◽  
Author(s):  
Magdalena Tuchowska ◽  
Barbara Muir ◽  
Mariola Kowalik ◽  
Robert P. Socha ◽  
Tomasz Bajda
Keyword(s):  
Photoelectron Spectroscopy ◽  
Low Cost ◽  
Inorganic Compounds ◽  
Ammonium Bromide ◽  
Reaction Products ◽  
X Ray Diffraction ◽  
X Ray ◽  
Before And After ◽  
Mineral Sorbent ◽  
Dimethyl Ammonium

Montmorillonite—the most popular mineral of the smectite group—has been recognized as a low-cost, easily available mineral sorbent of heavy metals and other organic and inorganic compounds that pollute water. The aim of this work was to determine the sorption mechanism and to identify the reaction products formed on the surface of montmorillonite and organo-montmorillonite after sorption of molybdates (Mo(VI)) and tungstates (W(VI)). Montmorillonites are often modified to generate a negative charge on the surface. The main objective of the study was to investigate and compare the features of Na-montmorillonite (Na-M), montmorillonite modified with dodecyl trimethyl ammonium bromide (DDTMA-M), and montmorillonite modified with didodecyl dimethyl ammonium bromide (DDDDMA-M) before and after sorption experiments. The material obtained after sorption was studied by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). The XRD pattern showed the presence of a new crystallic phase in the sample that was observed under an SEM as an accumulation of crystals. The FTIR spectra showed bands related to Mo–O and W–O vibration (840 and 940 cm−1, respectively). The obtained results suggest that molybdenum(VI) and tungsten(VI) ions sorb onto the organo-montmorillonite in the form of alkylammonium molybdates and tungstates.

Synthesis and characterization of organic–inorganic poly(3,4-ethylenedioxythiophene)/MoS2 nanocomposite via in situ oxidative polymerization

2006 ◽  
Vol 21 (1) ◽  
pp. 112-118 ◽  
Author(s):  
A. Vadivel Murugan ◽  
Mathieu Quintin ◽  
Marie-Helene Delville ◽  
Guy Campet ◽  
Annamraju Kasi Viswanath ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Oxidative Polymerization ◽  
X Ray Diffraction ◽  
Rechargeable Lithium Batteries ◽  
X Ray ◽  
Transmission Electron ◽  
Basal Distance ◽  
New Type

Here we demonstrate the synthesis of a new type of layered poly(3,4-ethylenedioxy- thiophene) (PEDOT)/MoS2 nanocomposite via flocculation of delaminated MoS2 with subsequent in situ oxidative polymerization of 3,4-ethylenedioxythiophene. The resulting nanocomposite was characterized by Fourier transform infrared spectroscopy, powder x-ray diffraction, x-ray photoelectron spectroscopy, thermal analysis, transmission electron microscopy, and four-probe electrical conductivity measurements with respect to temperature. X-ray diffraction results indicated that the exfoliated MoS2 and PEDOT are restacked to produce a novel nanoscale composite material containing alternate nanoribbons of PEDOT in between MoS2 with a basal distance of ∼1.38 nm. The nanocomposite, which could be used as a cathode material for small power rechargeable lithium batteries, has also been demonstrated by the electrochemical insertion of lithium into the PEDOT/MoS2 nanocomposite, where a significant enhancement in the discharge capacity is observed, compared to that of respective pristine molybdenum disulfide.

scholarly journals Selective adsorption of PHC and regeneration of washing effluents by modified diatomite

2020 ◽  
Vol 81 (10) ◽  
pp. 2066-2077
Author(s):  
Zhuoqi Xu ◽  
Gengbo Ren ◽  
Yanying Zhu ◽  
Xiaodong Ma ◽  
Hongrui Li ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Selective Adsorption ◽  
Low Cost ◽  
Soil Washing ◽  
X Ray Diffraction ◽  
X Ray ◽  
Monolayer Adsorption ◽  
Pseudo Second Order ◽  
Adsorption Desorption ◽  
Modified Diatomite

Abstract Selective removal of petroleum hydrocarbons (PHCs) from soil washing effluents is the key to the surfactant-enhanced soil washing technology. In this study, the diatomite was modified by nonionic surfactant TX-100 and applied in the selective adsorption of PHCs in the soil washing effluents. The modified diatomites were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, N2 adsorption/desorption and X-ray photoelectron spectroscopy respectively. The adsorption process followed the pseudo-second-order model and the adsorption isotherms indicated that the interaction between PHCs and modified diatomite was monolayer adsorption. The important operating factors such as TX-100 dosage, adsorbent dosage, time and temperature were optimized. With the participation of the low-cost adsorbent TX3-Db with high adsorption capacity, the recovery efficiency of the washing effluents was still up to 78.9% after three cycles. A selective adsorption mechanism, based on steric hindrance and electrostatic repulsion, was proposed to explain the removal of PHCs from washing effluents.

Nickel(II) cluster-based mixed-cation coordination polymer synthesized from 2-mercaptobenzoic acid and its application

2019 ◽  
Vol 75 (7) ◽  
pp. 877-882
Author(s):  
Jingyan Zhu ◽  
Shan Yan ◽  
Hongping Xiao ◽  
Jun Jiang ◽  
Xinhua Li
Keyword(s):  
Coordination Polymer ◽  
Photoelectron Spectroscopy ◽  
Functional Materials ◽  
Discharge Process ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mixed Cation ◽  
Chloride Hexahydrate ◽  
Potential Applications ◽  
Cation Coordination

High-nuclearity metal clusters have received considerable attention not only because of their diverse architectures and topologies, but also because of their potential applications as functional materials in many fields. To explore new types of clusters and their potential applications, a new nickel(II) cluster-based mixed-cation coordination polymer, namely poly[hexakis[μ4-(2-carboxylatophenyl)sulfanido]di-μ3-chlorido-tri-μ2-hydroxido-octanickel(II)sodium(I)], [Ni8NaCl2(OH)3(C7H4O2S)6] n , 1, was synthesized using nickel chloride hexahydrate and mercaptobenzoic acid (H2mba) as starting reactants under hydrothermal conditions. The material was characterized by single-crystal X-ray diffraction (SCXRD), Fourier transform IR spectroscopy, thermogravimetric analysis, powder X-ray diffraction and X-ray photoelectron spectroscopy analysis. SCXRD shows that 1 consists of a hexanuclear nickel(II) [Ni6] cluster, dinuclear NiII nodes and a mononuclear NaI node, resulting in the formation of a complex covalent three-dimensional network. In addition, a tightly packed NiO/C&S nanocomposite is fabricated by sintering the coordination precursor at 400 °C. The uniform nanocomposite consists of NiO nanoparticles, incompletely carbonized carbon and incompletely vulcanized sulfur. When used as a supercapacitor electrode, the synthesized composite shows an extra-long cycling stability (>5000 cycles) during the charge/discharge process.

In situ remediation of arsenic-rich mine tailings using slag zero valence iron

2020 ◽  
Vol 84 (3) ◽  
pp. 420-434
Author(s):  
Tingting Yue ◽  
Shu Chen ◽  
Jing Liu
Keyword(s):  
Photoelectron Spectroscopy ◽  
Solid Phase ◽  
Low Cost ◽  
Selective Extraction ◽  
Hunan Province ◽  
Control Group ◽  
X Ray Diffraction ◽  
Land Occupation ◽  
X Ray

AbstractArsenopyrite (FeAsS) and realgar (As4S4) are two common arsenic minerals that often cause serious environmental issues. Centralised treatment of arsenic-containing tailings can reduce land occupation and save management costs. The current work examined the remediation schemes of tailings from Hunan Province, China, where by different tailings containing arsenopyrite and realgar were blended with exogenous slag zero valence iron (ZVI). Introducing Fe-oxidising bacteria (Acidithiobacillus ferrooxidans) recreates a biologically oxidative environment. All bioleaching experiments were done over three stages, each for 7 days and the solid phase of all tests was characterised by scanning electron microscopy, X-ray diffraction, Fourier-transform infrared spectroscopy, X-ray photoelectron spectroscopy and selective extraction analyses. The results showed that the mixture group reduced arsenic release by 72.9–74.7% compared with the control group. The addition of 0.2 g ZVI clearly decreased arsenic release, and the addition of 4.0 g ZVI led to the lowest arsenic release among all tests. The decrease of arsenic released from the tailings was due to the adsorption and uptake of arsenic by secondary iron-containing minerals and Fe–As(V) secondary mineralisation. The addition of large amounts of ZVI reduced the arsenic detected in the amorphous Fe precipitates. Therefore, a low cost and integrated strategy to reduce arsenic release from tailings is to mix two typical tailings and apply exogenous slag ZVI, which can apply to the in situ remediation of two kinds or more arsenic-containing tailings.

Photoluminescence and I–V characteristics of ZnS grown on silicon nanoporous pillar array

2008 ◽  
Vol 23 (1) ◽  
pp. 121-126 ◽  
Author(s):  
Hai Jun Xu ◽  
He Shun Jia ◽  
Zhi Tao Yao ◽  
Xin Jian Li
Keyword(s):  
Grain Size ◽  
Photoelectron Spectroscopy ◽  
Heterogeneous Reaction ◽  
Optical And Electrical Properties ◽  
X Ray Diffraction ◽  
Pillar Array ◽  
X Ray ◽  
Patterned Surface ◽  
Forward Current ◽  
Average Grain Size

Silicon nanoporous pillar array (Si-NPA) is a silicon hierarchical structure with regularly patterned surface morphology. Through a heterogeneous reaction process, zinc sulfide nanocrystallites (nc-ZnS) were grown onto Si-NPA and a unique heterostructure of ZnS/Si-NPA was obtained. The formation of wurtzite nc-ZnS was proved by x-ray diffraction, and the average grain size was evaluated to be ∼18 nm. X-ray photoelectron spectroscopy disclosed that as-grown nc-ZnS was well separated from Si-NPA by a SiO2 thin layer of ∼1.3 nm. The photoluminescence (PL) spectrum of ZnS/Si-NPA showed that in addition to the two red PL bands peaked at ∼648 and ∼705 nm observed in Si-NPA, three other PL bands peaked at ∼365, ∼418, and ∼472 nm were observed and attributed to the PL from nc-ZnS. It was also demonstrated that as-prepared ZnS/Si-NPA heterostructure could exhibit good rectification characteristic featured by a high forward current density of ∼75 mA/cm2 at 2 V and high reverse breakdown voltage of ∼10 V. Our results indicated that ZnS/Si-NPA might be a valuable heterostructure nanosystem to be further probed for achieving enhanced optical and electrical properties.

scholarly journals Biochar as a low-cost, eco-friendly, and electrically conductive material for terahertz applications

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Woongkyu Park ◽  
Hyuntae Kim ◽  
Hajung Park ◽  
Soobong Choi ◽  
Sung Ju Hong ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Annealing Temperature ◽  
Low Cost ◽  
X Ray Diffraction ◽  
Electrically Conductive ◽  
X Ray ◽  
High Annealing ◽  
Structural And Electrical Properties ◽  
Terahertz Frequencies ◽  
Terahertz Conductivity

AbstractWe investigate conducting characteristics of biochar derived from the pyrolysis of a paper at terahertz frequencies. Paper is annealed under temperatures ranging from 600 to 1000 °C to modify structural and electrical properties. We experimentally observe that the terahertz conductivity increases above 102 S/m as the annealing temperature increases up to 800 °C. From structural characterization using energy-dispersive X-ray spectroscopy, Fourier-transform infrared spectroscopy, Raman spectroscopy, X-ray diffraction, and X-ray photoelectron spectroscopy, we confirm that more graphitic biochars are produced in high annealing temperature, in agreement with the improvement of terahertz conductivity. Our results show that biochar can be a highly promising candidate to be used in paper-based devices operating at terahertz frequencies.

Novel Method to Synthesize Ceria Coated Silica particles

2009 ◽  
Vol 1157 ◽  
Author(s):  
Myoung-hwan Oh ◽  
Jae Seok Lee ◽  
Sushant Gupta ◽  
Tae Kon Kim ◽  
Aniroddh Kaanna ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Silica Particles ◽  
X Ray Diffraction ◽  
Post Heat Treatment ◽  
X Ray ◽  
Transmission Electron ◽  
New Type ◽  
Novel Method ◽  
Alkoxide Method

AbstractMonodispersed ceria coated silica particles were prepared by a new type of ceria precursor. The ceria precursor was synthesized by alkoxide method, which employs ethanol as solvent. The synthesized particles were characterized with scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). It was found that well-crystalline ceria coatings were deposited on the surface of the silica particles without post-heat treatment. In addition, the coated particles prepared by a new precursor were uniformly dispersed without the formation of hard aggregate as compared to those obtained by conventional method.

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