scholarly journals Study on catalytic properties of graphene/molybdenum sulfide under near-infrared light irradiation

2022 ◽  
Vol 5 (1) ◽  
pp. 16
Author(s):  
Huan Zhang ◽  
Shouqing Liu

Graphene/MoS2 hybrid material was prepared by the hydrothermal method. The hybrid material was characterized by X-ray diffraction spectrum, Raman spectra, transmission electron microscope and UV-vis-NIRS. It was used as a near-infrared photocatalyst to catalyze and degrade Rhodamine B (RhB). The results showed that when the concentration of the RhB solution was 50.0 mg·L–1, the pH value of the solution was 7, the volume of the solution was 50.0 mL, the amount of G/MoS2 catalyst was 0.05 g and near-infrared radiation was carried out for 3 h, the degradation rate of RhB in the 50 mL solution reached 96.5%. When MoS2 was used as the photocatalyst, the degradation rate of RhB was only 75.5%. After 5 times of recycling, the catalytic efficiency of the hybrid photocatalyst was still more than 90%, indicating that the catalyst is very stable.

2006 ◽  
Vol 320 ◽  
pp. 113-116
Author(s):  
Shigeru Tanaka ◽  
Yukari Ishikawa ◽  
Naoki Ohashi ◽  
Junichi Niitsuma ◽  
Takashi Sekiguchi ◽  
...  

We have obtained Er-doped ZnO thin film in a micropattern of reverse trapezoids processed on Si substrate by sputtering and ultrafine polishing techniques. Near-infrared light emission was detected successfully from the thin film filling a single micropit with 10 μm square. Transmission electron microscopy (TEM) observation showed epitaxial growth of ZnO crystals along the curvature of the micropit.


Catalysts ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1238
Author(s):  
Murendeni P. Ravele ◽  
Opeyemi A. Oyewo ◽  
Sam Ramaila ◽  
Lydia Mavuru ◽  
Damian C. Onwudiwe

In this paper, spherical-shaped pure phase djurleite (Cu31S16) and roxbyite (Cu7S4) nanoparticles were prepared by a solvothermal decomposition of copper(II) dithiocarbamate complex in dodecanthiol (DDT). The reaction temperature was used to control the phases of the samples, which were represented as Cu31S16 (120 °C), Cu31S16 (150 °C), Cu7S4 (220 °C), and Cu7S4 (250 °C) and were characterized by using X-ray diffraction (XRD), scanning and transmission electron microscopy (SEM and TEM), and absorption spectroscopy. The samples were used as photocatalysts for the degradation of tetracycline (TC) under visible light irradiation. The results of the study showed that Cu7S4 (250 °C) exhibited the best activity in the reaction system with the TC degradation rate of up to 99% within 120 min of light exposure, while the Cu31S16 (120 °C) system was only 46.5% at the same reaction condition. In general, roxbyite Cu7S4 (250 °C) could be considered as a potential catalyst for the degradation of TC in solution.


Nanomaterials ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 1341 ◽  
Author(s):  
Ruiqi Wang ◽  
Duanyang Li ◽  
Hailong Wang ◽  
Chenglun Liu ◽  
Longjun Xu

S-doped Bi2MoO6 nanosheets were successfully synthesized by a simple hydrothermal method. The as-prepared samples were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscopy (TEM), N2 adsorption–desorption isotherms, Raman spectroscopy, Fourier transform infrared spectroscopy (FT-IR), elemental mapping spectroscopy, photoluminescence spectra (PL), X-ray photoelectron spectroscopy (XPS), and UV-visible diffused reflectance spectra (UV-vis DRS). The photo-electrochemical performance of the samples was investigated via an electrochemical workstation. The S-doped Bi2MoO6 nanosheets exhibited enhanced photocatalytic activity under visible light irradiation. The photo-degradation rate of Rhodamine B (RhB) by S-doped Bi2MoO6 (1 wt%) reached 97% after 60 min, which was higher than that of the pure Bi2MoO6 and other S-doped products. The degradation rate of the recovered S-doped Bi2MoO6 (1 wt%) was still nearly 90% in the third cycle, indicating an excellent stability of the catalyst. The radical-capture experiments confirmed that superoxide radicals (·O2−) and holes (h+) were the main active substances in the photocatalytic degradation of RhB by S-doped Bi2MoO6.


2016 ◽  
Vol 5 (5) ◽  
Author(s):  
Phuong Phong Nguyen Thi ◽  
Dai Hai Nguyen

AbstractWe report star-shaped silver@gold (Ag@Au) nanoparticles (NPs) in gelatin suspensions for the purpose of enhancing the stability of Ag@Au NPs. In this case, Ag NPs were designed as nucleating agents, whereas gelatin was used as a protecting agent for Au development. Especially, variable gelatin concentrations were also prepared to explore its ability to increase the stability of Ag@Au NPs. The obtained samples were then characterized by UV-visible spectroscopy, transmission electron spectroscopy (TEM), X-ray diffraction, and Fourier transform infrared spectroscopy. The maximum absorption wavelength of all samples (566–580 nm) indicated that branched Ag@Au@gelatin NPs were successfully synthesized. In addition, our TEM results revealed that the size of branched Ag@Au@gelatin NPs was found to be between 20 and 45 nm as influenced by the component ratio and the pH value. These results can provide valuable insights into the improvement of Ag@Au NP stability in the presence of gelatin.


2012 ◽  
Vol 602-604 ◽  
pp. 227-230
Author(s):  
Tao Fan ◽  
Yan Rong Sun ◽  
Li Guo Ma

Spheroid hydroxyapatite nanoparticles were successfully prepared by titrating Ca(NO3)2•4H2O and (NH4)2HPO4 aqueous solution in the reverse microemulsion, which consists of mixed OP-10(surfactant), cyclohexane(oil phase), and isobutanol (cosurfactant).The structure and morphology of the prepared powders were characterized by means of X-ray diffraction (XRD) and transmission electron microscope (TEM). The optimum composition was investigated via the analysis of the aqueous solution conductivity, and the mechanism of aqueous reaction. The effect of the pH value and the amount of surfactant on the particle size were studied. The results indicate that the best conditions are which the concentration of OP-10 and isobutanol both are 0.2 M, when the water content is between 130 ml-250 ml,it results in pure nano-hydroxyapatite spheroid-like powders, and the water content is about 200 ml, whose diameters are 50 nm-80 nm, and good particle diameter distribution, the particle microstructure is homogeneous, good crystal structure and higher crystallinity.


2015 ◽  
Vol 814 ◽  
pp. 596-600 ◽  
Author(s):  
Li Na Chen ◽  
Jin Feng Leng ◽  
Zhong Xi Yang ◽  
Zhi Chao Meng ◽  
Bin Sun

The Cu3N films were deposited successfully by reactive direct current magnetron sputtering, the films were comprehensively and systematically characterized by X-ray diffraction analyzer (XRD), UV-Visible spectrophotometer, four-probe resistance tester and other instruments. Results showed that under low deposition power (80W~100W), crystal orientation increased, which is attributed to higher energy under higher power. When sputtering power exceeded the value, excessive energy led to anti-sputtering hindering the process of further nucleation and growth of films. The transmittance of the films deposited under 100W reached the peak value of 78% on the scope of near-infrared light, and optical band gap (Eg) of 1.35ev. The resistivity of Cu3N films increased from 9.68×102Ω.cm to 2.12×103Ω.cm with increasing in sputtering power up to 100W.


2012 ◽  
Vol 724 ◽  
pp. 205-208
Author(s):  
Li Yan Zhang ◽  
Fen Wang ◽  
Jian Feng Zhu

ZnO nanorods were prepared by heat treating of aqueous zinc acetate treated with organic of PVA. The products were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) and transmission electron microscopy (TEM). The results indicate that the as synthesized ZnO are hexagonal wurtzite nanorods with the maximum aspect ratio of 10:1 (100 nm in diameter and about 1 μm in length). The morphology of nanorods was formed by the regulation of appropriate organic under a pH value of 8.5. The growth mechanism of ZnO is proposed that the nanocrystals grow along a preferred direction in a growth tunnel provided by organics.


2011 ◽  
Vol 236-238 ◽  
pp. 2076-2079
Author(s):  
Yan Rong Sun ◽  
Tao Fan ◽  
Yong Huang ◽  
Li Guo Ma ◽  
Feng Liu

The introduction of biomineralization was coupled with the co-precipitation synthesis process of nano-hydroxyapatite with the addition of chondroitin sulfate as a template agent. The effect of a variety of processing conditions on the properties of final hydroxyapatite (HA) product was investigated by orthogonal design. The ratio of calcium to phosphorus was detected by chemical analysis, the phase composition was evaluated by X-ray diffraction (XRD), and the powder morphology was characterized by transmission electron microscope (TEM). The process scheme, moreover, was optimized by the analysis of four aspects which may have different extent of influence on product properties. It can be concluded from the results that product properties can be affected remarkably by the content of chondroitin sulfate and the pH value of reactant, less remarkably by the reaction temperature and slightly by the reaction time.


2017 ◽  
Vol 727 ◽  
pp. 280-283
Author(s):  
Xiao Ming Fu

Anatase TiO2 particles of about 20 nm in the diameter were successfully synthesized with Ti (SO4)2 as titanium source and stronger ammonia water as precipitant at 240°C for 48 h with pH=5 using the hydrothermal method. The samples were characterized by X-ray diffraction (XRD), transmission electron microscope (TEM) and ultraviolet-visible absorption spectroscopy (UV-VIS). XRD analysis showed that the phase of the samples was anatase TiO2. TEM analysis confirmed that TiO2 particles of about 50 nm in the diameter were obtained when the pH value was 0.12. With the increasement of the pH value, the size of as-prepared TiO2 particles became remarkably fine. However, with the further increase of the pH value, the size of TiO2 particles was not obvious. TiO2 particles of about 20 nm in the diameter were obtained when the pH value was 5. And UV-VIS results showed that the size of anatase TiO2 nanoparticles, which became small, was propitious to the blue shift of their absorption peak.


2013 ◽  
Vol 678 ◽  
pp. 248-252
Author(s):  
K. Kavi Rasu ◽  
Dhandapani Vishnushankar ◽  
V. Veeravazhuthi

Bismuth sulfide (Bi2S3) and Polyvinyl pyrrolidone (PVP) encapsulated Bi2S3 Nanoparticles are synthesized from aqueous solutions at room temperature. Synthesized samples are subjected to UV-Visible Spectroscopy, X-Ray Diffraction (XRD), Scanning electron microscopy (SEM), Energy Dispersive Analysis of X-ray (EDAX), Transmission Electron Microscopy (TEM) and FT-IR studies and their results are compared. X-ray diffraction spectrum reveals the crystalline nature of the synthesized samples. Grain size value of PVP/ Bi2S3 nanoparticles show a decrease when compared to Bi2S3 nanoparticles and this ensures the good encapsulant effect of PVP on Bi2S3 nanoparticles. SEM images show that all the particles in the synthesized sample are nearly equal in size. From the TEM image we conclude that the particle size lies between 30nm to 70nm. Finally the samples are subjected to EDAX studies for determining their composition.


Sign in / Sign up

Export Citation Format

Share Document