scholarly journals Demonstration of the Formation of Porous Silicon Films with Superior Properties Formed on Polished (100) Si with Screen-Printed Back Contacts

2007 ◽  
Vol 31 ◽  
pp. 249-253 ◽  
Author(s):  
Priyanka Singh ◽  
Shailesh N. Sharma ◽  
G. Bhagavannarayana ◽  
M. Husain ◽  
M. Lal
Keyword(s):  
Porous Silicon ◽  
Gravimetric Analysis ◽  
Back Contact ◽  
X Ray Diffraction ◽  
Crystalline Perfection ◽  
X Ray ◽  
Anodization Time ◽  
Current Densities ◽  
Scanning Electron ◽  
Screen Printed

Porous silicon (PS) layers were formed by anodization on polished substrates of (1 0 0) Si at different current densities for a fixed anodization time of 30 mins. using different screenprinted/ evaporated back contacts (Ag, Al) respectively. The PS films has been characterized by high resolution X-ray diffraction (HRXRD), photoluminescence (PL), Scanning Electron Microscopy (SEM) and Fourier Transform Infrared (FTIR) techniques respectively. Porosity and thickness of PS layers were estimated by gravimetric analysis. The properties of PS formed using screen-printed Ag & Al as the back contacts (SP-(Ag/Al)) was found to be superior as compared to the corresponding films with evaporated back contacts (EV-(Ag/Al)). The PS formed with screenprinted Ag & Al-back contacts shows better crystalline perfection, higher stability, higher PL efficiency and negligible PL decay compared to that formed with evaporated Ag & Al- as the back contact for the same current density and time of anodization.

Effect of Au on the Performance of Porous Silicon/V2O5 Nanorods Heterojunctions to NO2 Gas

NANO ◽  
2016 ◽  
Vol 11 (07) ◽  
pp. 1650079 ◽  
Author(s):  
Wenjun Yan ◽  
Ming Hu ◽  
Jiran Liang ◽  
Dengfeng Wang ◽  
Yulong Wei ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Porous Silicon ◽  
Room Temperature ◽  
Au Nanoparticles ◽  
Analytical Techniques ◽  
Heating Process ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Electron

A novel composite of Au-functionalized porous silicon (PS)/V2O5 nanorods (PS/V2O5:Au) was prepared to detect NO2 gas. PS/V2O5 nanorods were synthesized by a heating process of pure vanadium film on PS, and then the obtained PS/V2O5 nanorods were functionalized with dispersed Au nanoparticles. Various analytical techniques, such as field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), have been employed to investigate the properties of PS/V2O5:Au. Herein, the PS/V2O5:Au sample exhibited improved NO2-sensing performances in response, stability and selectivity at room temperature (25[Formula: see text]C), compared with the pure PS/V2O5 nanorods. These phenomena were closely related to not only the dispersed Au nanoparticles acting as a catalyst but also the p-n heterojunctions between PS and V2O5 nanorods. Whereas, more Au nanoparticles suppressed the improvement of response to NO2 gas.

Synthesis of Novel Carbon Spheres and Study on Graphitization Process

2013 ◽  
Vol 634-638 ◽  
pp. 2293-2296
Author(s):  
Ai Li Ma ◽  
Cheng Qian Li ◽  
Wu Qing Du ◽  
Jie Chang
Keyword(s):  
High Temperature ◽  
Microwave Plasma ◽  
Gravimetric Analysis ◽  
Thermal Gravimetric ◽  
Carbon Spheres ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cvd Method ◽  
Graphitization Degree ◽  
Scanning Electron

In this paper, carbon spheres were synthesized by CVD method. These carbon spheres exhibit diameters of about 200 nm. Thermal gravimetric analysis indicated the good stability in high temperature of the carbon spheres. The products were treated by microwave plasma and high temperature vacuum heat treatments respectively. The products were characterized by X-ray diffraction, Raman spectroscopy and Field Emission Scanning Electron Microscope. The study indicated that the original products, with perfect morphology and low graphitization degree, were converted to crystal. The different techniques were considered for the influence on the graphitization degree.

The Utilization of Recycled Newspaper in the Production of Cellulose Microfiber

2016 ◽  
Vol 1133 ◽  
pp. 644-648 ◽  
Author(s):  
Mohamad Azuwa Mohamed ◽  
Wan Norharyati Wan Salleh ◽  
Juhana Jaafar ◽  
Ahmad Fauzi Ismail
Keyword(s):  
Electron Microscopy ◽  
Cost Effective ◽  
Gravimetric Analysis ◽  
Thermal Gravimetric ◽  
X Ray Diffraction ◽  
X Ray ◽  
Reinforcement Material ◽  
Cellulose Microfibers ◽  
Thermal Stability Of ◽  
Scanning Electron

Cellulose microfibers (CMF) were produced by utilizing recycled newspaper paper (RNP) as starting material. This approach is considered as green since recycling newspaper leads to the environment preservation and also cost-effective. The effect on the structural properties of cellulose produced at different stage of pretreatment were investigated by using Fourier transform infrared (FTIR), Scanning electron microscopy (SEM), X-ray diffraction (XRD) and Thermal gravimetric analysis (TGA). The FTIR and SEM demonstrate that the hemicellulose and lignin was successfully removed from the structure of the CMF. XRD and TGA results revealed that the different step of pretreatment was increased the crystallinity and thermal stability of CMF increased gradually. The improvement in CMF crystallinity has improved its thermal properties which is important in the field of reinforcement material.

scholarly journals Evaluation of LDPE Degradation Under Controlled Composting

2021 ◽  
Vol 20 (3) ◽  
Author(s):  
S. Singh ◽  
S. Shankar ◽  
Shikha .
Keyword(s):  
Major Change ◽  
Natural Ecosystem ◽  
Gravimetric Analysis ◽  
Thermal Gravimetric ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Sem Images ◽  
X Ray ◽  
Polyethylene Films ◽  
Scanning Electron

The compost burial test was performed to determine the degradation of commercially available low-density polyethylene in natural compost for a period of six months. Biodegradability of polyethylene films in compost was monitored using scanning electron microscopy (SEM), Energy dispersive X-Ray, Fourier transform infrared spectroscopy (FTIR), X-Ray diffraction (XRD), thermal gravimetric analysis (TGA), differential scanning calorimetry (DSC), and weight reduction analysis. After six months of compost exposure, a major change over the surface of LDPE was observed. SEM images clearly showed the exfoliation and cracks on the film leading to degradation. The other analysis also showed a change in the thermal properties and crystallinity of the LDPE films. The composting method could prove to be the reliable and ecological method of degrading plastic waste without hindering the natural ecosystem.

Photocatalytic Oxidation Removal of Gaseous Benzene over TiO2 /ACF Composite Photocatalyst Prepared by Screen-Printed Technology

2011 ◽  
Vol 197-198 ◽  
pp. 943-946
Author(s):  
Li Li Liu ◽  
Chang Yu Li
Keyword(s):  
Thin Film ◽  
Photocatalytic Oxidation ◽  
X Ray Diffraction ◽  
Composite Photocatalyst ◽  
X Ray ◽  
Phase Structures ◽  
Volatile Organic ◽  
Gaseous Benzene ◽  
Scanning Electron ◽  
Screen Printed

The TiO2 /ACF composite photocatalyst was prepared by using the screen printed technology. X-ray diffraction (XRD) and scanning electron microscopy ( SEM) were used to characterize the obtained composite. The results of XRD show the TiO2 /ACF composite photocatalyst is confirmed anatase as the only phase present and ACF has no effects on the phase structures of TiO2. The results of SEM show that TiO2 can form thin film on ACF surface. Benzene was chosen as the model of the volatile organic compounds (VOCs) to investigate the capability of TiO2/ACF composite photocatalyst. The results show the TiO2/ACF composite photocatalyst have higher activity for benzene removal than only TiO2 photocatalyst.

Study on Effective Elastic Properties of CaMnO3

2018 ◽  
Vol 16 (14) ◽  
pp. 20-22
Author(s):  
Prapawan Thongsri
Keyword(s):  
High Performance ◽  
Effective Elastic Modulus ◽  
Direct Impact ◽  
Sintering Process ◽  
Hot Press ◽  
X Ray Diffraction ◽  
Aging Behavior ◽  
Crystalline Perfection ◽  
X Ray ◽  
Scanning Electron

Abstract Calcium manganese oxide (CaMnO3) polycrystalline was synthesized by solid state reaction (SSR) and hot-press (HP) methods. The powder of CaCO3 and MnO2 were mixed by ball milling then calcined at 850°C for 10 h and hotpressing at 850 °C for 1 h to obtain the CaMnO3 samples. The crystallography of the samples was analyzed by the X-ray diffraction (XRD). The microstructures of the samples were observed by scanning electron microscope (SEM). It was found that, the sintering process influence the crystalline perfection and have a direct impact on the mechanical properties of CaMnO3 and their aging behavior. The values of the effective elastic modulus was 6 GPa and Flexural strength was 0.417 MPa of CaMnO3 were found to be in the range of corresponding values for high performance and possibility fabricated n-type thermoelectric leg.

Growth of ZnO Microstructure on Porous Silicon

2019 ◽  
Vol 290 ◽  
pp. 261-266
Author(s):  
Nurizati Rosli ◽  
Mohd Mahadi Halim ◽  
M. Roslan Hashim
Keyword(s):  
Electron Microscopy ◽  
Porous Silicon ◽  
Growth Time ◽  
X Ray Diffraction ◽  
High Quality ◽  
X Ray ◽  
Good Crystallinity ◽  
Wurtzite Lattice ◽  
Cbd Method ◽  
Scanning Electron

In this study, Zinc Oxide (ZnO) microstructures were grown on porous silicon (PS) using chemical bath deposition (CBD) method by varying the growth time. The field emission scanning electron microscopy (FESEM) revealed the morphology and sized of ZnO. The X-ray diffraction (XRD) spectra indicate the high quality growth of ZnO on PS surface. Raman analyses revealed the peaks shift of E2(High), characterized wurtzite lattice and indicates good crystallinity of ZnO.

scholarly journals Avaliação do bagaço de cana natural e modificado como potencial sorvente de óleo vegetal

2016 ◽  
Vol 11 (4) ◽  
pp. 129
Author(s):  
Viviane Vasques da Silva Guilarduci ◽  
Honória Fátima Gorgulho ◽  
Patrícia Benedini Martelli ◽  
Vanessa Soares dos Santos ◽  
William Graciliano Corrêa
Keyword(s):  
Electron Microscopy ◽  
Acetic Anhydride ◽  
Vegetable Oil ◽  
Sugarcane Bagasse ◽  
Gravimetric Analysis ◽  
Thermal Gravimetric ◽  
X Ray Diffraction ◽  
X Ray ◽  
Oily Water ◽  
Scanning Electron

O óleo e a gordura vegetal residual, utilizados para a preparação de alimentos representam um perigoso poluente para as águas de córregos e rios. Um dos métodos mais utilizados nas últimas décadas para limpeza da água oleosa é a aplicação de biossorventes, pois apresentam facilidade para remoção e recuperação do óleo. Neste sentido, o objetivo deste trabalho foi determinar a influência das modificações do bagaço de cana com anidrido acético (acetilação) e com 3-aminopropiltrietoxisilano (silanização) sob a sorção de óleo vegetal. A modificação das fibras foi avaliada pelas técnicas de espectroscopia no infravermelho com transformada de Fourier (FTIR), análise termogravimétrica (TG), difração de raios X, microscopia eletrônica de varredura (MEV) e análise de área superficial e porosidade. Os resultados obtidos indicaram maior sorção de óleo vegetal para o bagaço de cana modificado com anidrido acético (BCA), 667 mg.g-1, seguido pelo bagaço de cana sem modificação (BCN) com sorção de 576 mg.g-1. O bagaço de cana modificado com 3-aminopropiltrietoxisilano (BCS) apresentou menor sorção, 425 mg.g-1, o que foi atribuído à sua maior hidrofilicidade.Evaluation of natural and modified sugarcane bagasse as sorbent of vegetable oil Abstract: The oil and the residual vegetable fat, used for the preparation of foods represent a dangerous pollutant for the waters of streams and rivers. One of the most used methods in the last decades for cleaning the oily water is the application of biosorbents, since they are easy to remove and recover the oil. In this sense, the purpose of this work was to determine the influence of the modifications of sugarcane bagasse with acetic anhydride (acetylation) and with 3-aminopropyltriethoxysilane (silanization) under sorption of vegetable oil. The BCN and the grafted products were further characterized by FTIR spectroscopy, thermal gravimetric analysis, X-ray diffraction, scanning electron microscopy and analysis of surface area and porosity. The results showed higher sorption of vegetable oil for the acetic anhydride-modified sugarcane bagasse (BCA), 667 mg.g-1, followed by sugarcane bagasse without modification (BCN) with sorption of 576 mg.g-1. The cane bagasse modified with 3-aminopropyltriethoxysilane (BCS) presented lower sorption, 425 mg.g-1, which was attributed to its greater hydrophilicity.  

Characterization of Geological Materials of São Fidélis/BR for Slip Use

2012 ◽  
Vol 727-728 ◽  
pp. 710-714
Author(s):  
Zélia Maria Peixoto Chrispim ◽  
Luciana Lezira Pereira Almeida ◽  
Izabel de Souza Ramos ◽  
Maria da Gloria Alves ◽  
Jonas Alexandre
Keyword(s):  
Gravimetric Analysis ◽  
Thermal Gravimetric ◽  
X Ray Diffraction ◽  
X Ray ◽  
Geological Materials ◽  
Physical Chemical ◽  
Mineralogical Compositions ◽  
Scanning Electron ◽  
Do So

The present work was performed in São Fidélis/BR, technologically characterizing four types of soil. Aiming to use them in artistic ceramic, some of their properties were determined, such as the analysis of color after burn. In order to do so, essays regarding their granulometry (sifting and sedimentation), specific gravity, chemical analysis of xray fluorescence, mineralogical identification through x-ray diffraction (DRX), differential thermal analysis (ATD), thermal gravimetric analysis (TG) and scanning electron microscopy (MEV) were carried out in the Laboratories of Universidade Estadual do Norte Fluminense (UENF).The soils were analyzed before drying at 110°C and after burn under temperatures of 750°C and 1,050°C. The analyses of results returned their physical, chemical and mineralogical compositions. Many variations of color could be observed after burn.

The Preparation And Electrochemical Performance Analysis of Different Porous Silicon Composites

2021 ◽  
Author(s):  
Xuchun Wang ◽  
Qianrui Liu ◽  
Jiaohong Shu ◽  
Dongdong Ouyang ◽  
Xuemei Zhang ◽  
...  
Keyword(s):  
Porous Silicon ◽  
Anode Materials ◽  
Electrochemical Techniques ◽  
Specific Capacity ◽  
Lithium Ion ◽  
X Ray Diffraction ◽  
X Ray ◽  
Porous Silicon Substrate ◽  
Interfacial Impedance ◽  
Scanning Electron

Abstract In this work, LiAlH4 is used to reduce SiO2 to porous silicon, and then nano-silver (AgNPs) and Li2CO3 are attached to porous silicon substrate to form different porous silicon composites. X-ray diffraction (XRD) and scanning electron microscopy (SEM) are applied to characterize the morphology of porous silicon composites, and porous silicon composites are tested via electrochemical techniques. The experimental results present that porous silicon composites loaded with AgNPs (Si-Ag) show higher specific capacity (476.0195 mA·h·g-1) and lower interfacial impedance compared with composites loaded with Li2CO3 (Si-Li2CO3). Si-Ag composites are suitable to be used as anode materials for lithium-ion batteries.

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