Ceramics International 

About: Ceramics International is an academic journal published by Elsevier BV. The journal publishes majorly in the area(s): Materials science & Ceramic. It has an ISSN identifier of 0272-8842. Over the lifetime, 36430 publications have been published receiving 685042 citations.

Detection of hazardous volatile organic compounds (VOCs) by metal oxide nanostructures-based gas sensors: A review

Abstract: Since the sensing capability of semiconducting metal oxides was demonstrated in the 1960s, solid state gas sensors based on these materials have attracted considerable attention from both scientific and practical point of view. Because of the promising characteristics for detecting toxic gases and volatile organic compounds (VOCs) compared to conventional techniques, these devices are expected to play a key role in environmental monitoring, chemical process control, personal safety and so on in the near future. Therefore, in recent years, intensive studies have been conducted to improve their sensing performances, particularly to increase the sensitivity and detection limit of such devices. This can be accomplished by using metal oxide nanostructures with various shapes such as nanoparticles, nanowires, nanorods and nanotubes having sizes in the nanometer range. Owing to the high surface-to-volume ratios and consequently large number of surface sites exposed to target gas, nanostructured metal oxides enable a larger gas-sensing layer interaction and hence a higher sensitivity in comparison with conventional materials. This article extensively reviews recent developments in this field, focusing the attention on the detection of some common VOCs, including acetone (C3H6O), acetylene (C2H2), benzene (C6H6), cyclohexene (C6H10), ethanol (C2H5OH), formaldehyde (HCHO), n-butanol (C4H9OH), methanol (CH3OH) toluene (C7H8), and 2-propanol (C3H8O), by means of conductometric solid state sensors based on nanostructured semiconducting metal oxides.

XPS and optical studies of different morphologies of ZnO nanostructures prepared by microwave methods

Abstract: Zinc oxide (ZnO) nanostructures of various morphologies were prepared using a microwave-assisted aqueous solution method. Herein, a comparative study between three different morphologies of ZnO nanostructures, namely nanoparticles (NPs), nanoflowers (NFs) and nanorods (NRs) has been reviewed and presented. The morphologies of the prepared powders have been studied using field effect scanning electron microscopy (FESEM). X-ray diffraction (XRD) results prove that ZnO nanorods have biggest crystallite size compared with nanoflowers and nanoparticles. The texture coefficient (Tc) of three morphologies has been calculated. The Tc changed with varying morphology. A comparative study of surfaces of NPs, NFs and NRs were investigated using X-ray photoelectron spectroscopy (XPS). The possible growth mechanisms of ZnO NPs, NFs and NRs have been described. The optical properties of the ZnO nanostructures of various morphologies have been investigated and showed that the biggest crystallite size of ZnO nanostructures has lowest band gap energy. The obtained results are in agreement with experimental and theoretical data of other researchers. Crown Copyright & 2012 Published by Elsevier Ltd and Techna Group S.r.l. All rights reserved.

Substituted hydroxyapatites for biomedical applications: A review

Abstract: This review summarizes recent and very recent work on preparing substituted hydroxyapatites. Ease of atomic doping or substitution in apatite opens this mineral up for a wide range of biomedical applications. It can be used for repairing and replacing diseased and damaged parts of musculoskeletal systems, and also as a drug or gene delivery agent, as a bioactive coating on metallic osseous implants, biomagnetic particles and fluorescent markers. First, the physicochemical properties of bioapatites are described and discussed. Then a general summary on substitution reaction for hydroxyapatite is made. Special attention is paid to describing anionic, cationic and multisubstituted hydroxyapatites used for various biomedical applications. Finally, conclusions are drawn and future perspectives are discussed.

Zinc oxide nanoparticles: Biological synthesis and biomedical applications

Abstract: Nanotechnology is termed as a result of the synthesis, characterization, exploration, and application of nano-sized materials in the event of science and technology. In recent years, zinc oxide nanoparticles (ZnO-NPs) as an important ceramic materials are utilized in completely different industrial sectors such as medication, cosmetic materials and concrete, opposed microorganism, textile and automotive industries. Many chemical and physical methods were applied for preparing of ZnO-NPs but biological methods as “green” routes in different substrates (e.g., microorganisms, enzymes, bacteria, and plant extracts) are potentially steered as eco-friendly alternatives in comparison with chemical and/or physical techniques. At the present, ZnO-NPs are being investigated as associates of antibacterial agents in each microscale and nanoscale formulation. The ZnO-NPs are widely wont to treat a range of different skin conditions and have anticancer properties. In addition, ZnO-NPs have emerged as a suitable tool in drug delivery and sensing horizon. In this review, we summarize the green and biological synthesis methods of ZnO-NPs and investigation of their biomedical applications.

XPS and structural studies of high quality graphene oxide and reduced graphene oxide prepared by different chemical oxidation methods

Abstract: High quality graphene oxide (GO) and reduced graphene oxide (rGO) have been synthesized by chemical oxidation of graphite flakes via three modified Hummers methods using a mixture of sulfuric acid (H2SO4), phosphoric acid (H3PO4) and nitric acid (HNO3) as intercalating agents and potassium permanganate (KMnO4) and hydrogen peroxide (H2O2) as oxidizing agents. In this study the production of dangerously explosive gases was avoided. The temperature was carefully controlled using ice baths, ensuring the temperature was kept at the minimum during the reaction. The prepared samples were extensively characterized using various techniques including X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), high-resolution transmission electron microscopy (HRTEM), Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS). The results indicated greater presence of oxygen containing groups and an increase in the (C/O) ratio, both of which served as reliable indicators of high quality graphene oxide. Atomic ratio of carbon to oxygen (C/O) quantified by XPS was calculated to be 25.67, 1.81, 1.63, and 2.77 of graphite, GO-I, GO-II, and GO-III, respectively. As revealed by FTIR analysis, the GO-I had more hydrophilic oxygen functional groups compared to GO-II and GO-III.