Amin Termeh Yousefi

Enhanced DSSCs efficiency via Cooperate co-absorbance (CdS QDs) and plasmonic core-shell nanoparticle (Ag@PVP).

This paper describes cooperate the co-absorbance (CdS QDs) and the plasmonic core-shell nanoparticles (Ag@PVP) of dye synthesized solar cells in which CdS QDs and Ag@PVP are incorporated into the TiO2 layer. Cooperative nanoparticles show superior behavior on enhancing light absorption in comparison with reference cells. Cooperated DSSC exhibits the best performance with the power conversion efficiency of 7.64% which is superior to that of the free–modified DSSC with the PCE of 5%. Detailed studies offer an effective approach to enhance the efficiency of dye synthesized solar cells.

Simulation of Nano Sensor Based on Carbon Nanostructures in Order to Form Multifunctional Delivery Platforms

Carbon nanostructures demonstrate a perfect combination of mechanical, electrical and electro chemical properties.Different approaches can improve the selectivity and sensitivity of CNT-modified electrode through immobilization of enzymes. In this research, simulation of SWCNTs attached sensor for medical application was described.Glucose oxidase was immobilized on the surface of the CNT using microencapsulation technique with non covalent bindings which has a negligible effect on the native biological activities of the enzymes. The main advantage of the Micro-encapsulation is that the entrapped particles often maintain its nature bioactivity. ABAQUS and ANSYS are the softwares which used to certify the results of experiments. Boundary conditions were selectivity detected according to the redox reaction center of enzyme and electrode surface. The results of the simulation indicate the ability of CNT to penetrate into the cells which offers the potential of using CNT as vehicles for the delivery system. Furthermore, encapsulated CNT attached sensor can work as a stress sensor simultaneously. Simulation was focused on measuring physical properties of CNTs, such as Mass, velocity, capacity and stress before and after immobilizing of GOx.

TiO2 hybrid photocatalytic systems: impact of adsorption and photocatalytic performance

Abstract For the past 40 years, titanium dioxide (TiO2) nanomaterials have attracted immense attention because of their potential applications in the photodegradation of organic pollutants, photocatalytic water splitting for H2 generation, and dye-sensitized solar cells. Despite the fact that the potential applications of TiO2 nanoparticles are ubiquitous, they are not problem free, examples include a large interfacial area that causes slow charge carrier transport, a wide optical band gap that leads to limited applications using solar light, and single-phase and nanoscales features that induce fast recombination of photo-reduced carriers. Therefore, this review highlights the development associated with the adsorption photocatalysis hybrid system for treating wastewater. The immobilization of TiO2 photocatalysts in metal oxide, carbon, and ceramic materials to form TiO2 hybrid systems could prevent the problem of particle recovery, adsorption capacity, and the separation process. Such hybrid systems require significant effort of optimizing the specific surface area-to-volume ratio of the supported photocatalysts with its photocatalytic activities.

Continuous synthesis of well-crystalline VACNTs using CVD method for engineering applications

Abstract The extraordinary properties exhibited by carbon nanotubes (CNTs) make them one of the most active research studies among the researchers. In this paper, the optimum growth conditions for the synthesis of highly crystalline CNTs in order to improve their physical properties were presented. Chemical vapour deposition (CVD) was used to synthesise well-crystalline CNTs with uniform orientation using camphor oil as carbon source and argon gas as a carrier gas in the presence of ferrocene as a metal catalyst. The effects of four critical parameters, namely gas-flow rate, temperature, reaction time and the ratio of catalyst to carbon source on the crystallinity of CNTs, were investigated. The FESEM and TEM images, supported by the plot of Raman spectra emphasised the morphological improvement of the grown CNTs. It was found that crystalline CNTs can be synthesised using CVD method via restriction of the effective parameters.

Progress on nanoparticle-based carbon nanotube complex: fabrication and potential application

Abstract Carbon nanotubes (CNTs) are considered as one of the most intensively explored nanostructured materials and have been widely used as a platform material for metal and semiconductor nanoparticles (NPs) due to their large and chemically active surface area. Several approaches have been described in the literature to immobilize NPs on the surface of CNTs. This report reviews the recent developments in this area by exploring the various techniques where nanotubes can be functionalized with NPs to improve the optical, mechanical, thermal, medical, electrical, and magnetic applications of CNTs.

Selective aspect ratio of CNTs based on annealing temperature by TCVD method

Various aspect ratios of CNTs reported based on alteration of annealing temperature using thermal-chemical vapor deposition (TCVD) method. Also the growth dependent and independent parameters of the carbon nanotube (CNTs) array were studied as a function of synthesis method. The FESEM images indicate that the nanotubes are approximately perpendicular to the surface of the silicon substrate and form carbon nanotubes in different aspect ratios according to the applied annealing temperature. Furthermore, due to the optimized results it can be observed that, the mechanism of the CNTs growth is still present in the annealing step as well as deposition process and the most CNTs with crystalline aspect, produced in the annealing temperature, which was optimized at 700 - 900 ˚C. This result demonstrates that the growth rate, mass production, diameter, density, and crystallinity of CNT can be controlled by the annealing temperature.

Growth of well-oriented VACNTs using thermal chemical vapor deposition method

The remarkable properties of carbon nanotubes (CNTs) make them attractive for biosensor applications, especially for medical detecting devices. In this paper, we describe a process to grow high oriented ratio CNT arrays to improve the electrical properties of the devices based on CNTs. Chemical vapor deposition (CVD) was used to grow highly oriented CNT using camphor as the carbon source, and argon and hydrogen as carrier gases to grow perpendicular CNTs on the surface of the silicon substrate in presence of ferrocene as a metallic catalyst. Images were revealed by FESEM indicates that the formation mechanism of oriented CNTs with high morphological purity nanotubes, which is depends significantly on deposition time and applied temperature to the furnaces. This method might be an effective method to produce oriented MWCNT in different length.

Simulation of CNT-AFM tip based on finite element analysis for targeted probe of the biological cell

Carbon nanotubes (CNTs) are potentially ideal tips for atomic force microscopy (AFM) due to the robust mechanical properties, nano scale diameter and also their ability to be functionalized by chemical and biological components at the tip ends. This contribution develops the idea of using CNTs as an AFM tip in computational analysis of the biological cell’s. Finite element analysis employed for each section and displacement of the nodes located in the contact area was monitored by using an output database (ODB). This reliable integration of CNT-AFM tip process provides a new class of high performance nanoprobes for single biological cell analysis.

Controlling of deposition time as an effective parameter on purified growth CNTs based on TCVD method

According to the unique properties of Carbon nanotubes (CNTs), they have been under scientific investigation for more than fifteen years in different applications. Here we reported the effect of temperature on camphor in a wide range of 500–1150 ˚C. The results indicate that camphor did not decompose below 500 ˚C but very short-length tubes emerged from the silicon substrate at 550 ˚C which is suggesting that the catalyst activity. According to the results, the CNT growth rate was abruptly increased at 600 ˚C. This process was done on the same condition by optimizing the temperature up to 900 ˚C. FESEM images indicate the highest catalyst activity at 850 ˚C which direct the experiment to grow purified CNT up to 3 µm in the length. This result suggests that, at low temperatures, the catalyst–support interaction is strong enough not to let the metal particles to involve in deposition process, but at 850 ˚C MWCNTs and SWCNTs can be selectively grown as a function of CVD temperature. The optimum deposition ti...