Powder Metallurgy and Advanced Materials最新文献

{"title":"Comparative study of structural and optical properties of zirconium-doped indium oxide synthesized by solid state reactions and sol-gel technique","authors":"O. Nemeș, J. Chelaru, K. Magyari, L. Bizo","doi":"10.21741/9781945291999-19","DOIUrl":"https://doi.org/10.21741/9781945291999-19","url":null,"abstract":"In the present work the effect of zirconium doping (1.5 at.%) on the structural and optical properties of indium zirconium oxide was studied. Zr-doped indium oxides were prepared by using two different methods, solid state reactions and sol-gel technique. The compositions with bixbyite structure have been synthesized by two different methods, solid state reactions in air and sol-gel process. X-ray powder diffraction (XRPD) used for phases analysis confirm the validity of the cubic bixbyite-type structure of In2O3. The optical properties of the prepared composition were considered in terms of their diffuse reflectance spectra (DRS). The morphology of crystals was evidenced by SEM analyses and reveal agglomeration of particles with their size ranges in the micrometer domain. Introduction Transparent conducting oxides (TCOs) are an important class of materials which have attracted much attention in the last years due to their main properties, low resistivity and high optical transparency. The dominant TCOs are mainly zinc oxide (ZnO), indium oxide (In2O3) and tin oxide (SnO2), as well as subsequent mixtures of these, such as well-known indium tin oxide (ITO) [1]. In2O3, a wide-bandgap n-type semiconductor, is widely used in various applications due to their properties including solar applications, the transparent electrodes in various optoelectronic devices, the flat panel liquid crystals displays, the barrier layers in tunnel junctions, the active layers of gas sensors or the material for ultraviolet lasers [2]. Therefore, the physical properties of the In2O3, like high electrical conductivity and optical transparency in the visible range, strongly depend on the preparation method. For this reason there are many investigations which are studying their properties in dependence on the synthesis methods. These methods include physical methods such as sputtering, evaporation, pulsed laser deposition, spray pyrolysis, as well as chemical methods like chemical pyrolysis, chemical vapor deposition, sol-gel, bath deposition and electroplating [3–8]. On the other hand electrical properties of In2O3 can be improved by doping with metallic donor impurity. For this reason the system ZrO2–In2O3 was mostly investigated [810]. Powder Metallurgy and Advanced Materials – RoPM&AM 2017 Materials Research Forum LLC Materials Research Proceedings 8 (2018) 167-172 doi: http://dx.doi.org/10.21741/9781945291999-19 168 In the present paper we comparatively investigated the structural evolution, optical and morphological properties of indium zirconium oxide prepared by two methods, solid state synthesis and sol-gel route. Materials and Methods Synthesis Two different preparation methods were employed in the synthesis of zirconium-doped indium oxide: solid state synthesis and sol-gel method. Compositions belonging to In2-xZrxO3 (0.025 ≤ x ≤ 0.15) system with the bixbyite structure were prepared by solid state reactions from mixtures of pure In2O3 (Alfa Aesar 99.995%) and ZrO","PeriodicalId":20390,"journal":{"name":"Powder Metallurgy and Advanced Materials","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73317433","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Green synthesis of silver chloride nanoparticles using Rhodotorula Mucilaginosa","authors":"I. Ghiuta, D. Cristea, R. Wenkert, D. Munteanu","doi":"10.21741/9781945291999-4","DOIUrl":"https://doi.org/10.21741/9781945291999-4","url":null,"abstract":"The biosynthesis of silver chloride nanoparticles (AgCl NPs) is presented in this paper. Silver chloride nanoparticles were synthesized using fungi culture from Rhodotorula Mucilaginosa and aqueous AgNO3 solution, as precursor. The plasmon resonance of the nanoparticles containing solution has shown through UV-visible spectrophotometry an absorbance peak at about 437 nm. Scanning Electron Microscopy, Energy Dispersive Spectroscopy, and X-ray Diffraction analyses confirmed the presence of spherical silver chloride nanoparticles with a face centered cubic crystal structure and an average particle size of 25 nm. Silver chloride nanoparticles have been shown to be able to inhibit the growth of different microorganisms, including bacteria and fungi, which would make them suitable for antimicrobial applications. Introduction The development of materials and structures at nanoscale dimensions has gained a huge interest in the nanomaterials and nano-technology research fields. One of the most important properties of metallic nanoparticles is their antimicrobial activity. Eco-friendly methods concerning nanomaterials synthesis present a substantial importance for biological applications, mainly due to nontoxic substances and environmentally friendly procedures employed [1]. Green synthesis of silver chloride nanoparticles has been reported to be mediated by different kinds of organisms, from bacteria to plant extracts. Cell-free culture supernatant of Streptomyces strain, Klebsiella planticola, biomass of Bacillus subtilis, leaf extract of Cissus quadrangularis, aqueous extract of Sargassum plagiophyllum, extract from needles of Pinus densiflora, Prunus persica L. outer peel extract are just a few examples of organisms able to synthesize AgCl NPs [2]-[8]. Weili Hu et al. have presented the synthesis of silver chloride nanoparticles under ambient conditions in nanoporous bacterial cellulose membranes as nanoreactors. It has been demonstrated that the synthesized silver chloride nanoparticles exhibited high hydrophilic ability and a strong antimicrobial activity against Staphylococcus aureus and Escherichia coli bacteria [9]. The antibacterial effect of biosynthesized AgCl NPs investigated against Escherichia coli was found to be dose-dependent [6]. The biosynthesized silver chloride nanoparticles exhibited besides the antimicrobial activity, cytotoxicity activity against HeLa and SiHa cancer cell lines [2]. Powder Metallurgy and Advanced Materials – RoPM&AM 2017 Materials Research Forum LLC Materials Research Proceedings 8 (2018) 28-34 doi: http://dx.doi.org/10.21741/9781945291999-4 29 M. Sophocleous and J. K. Atkinson have described in their review the significant development of Ag/AgCl screen printed sensors [10]. Moreover, Ag/AgCl NPs are examined for further applications of nanoparticles as a plasmonic photocatalyst [6]. The reports which have shown the importance of the AgCl NPs application, from sensors, catalysts, to antimicrobial activity, have led","PeriodicalId":20390,"journal":{"name":"Powder Metallurgy and Advanced Materials","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73621569","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}