Atmospheric Pressure Plasma Systems and Applications

Atmospheric-pressure plasmas have a wide variety of potential industrial applications. They are used in extractive metallurgy; metal recovery; novel nanomaterial synthesis; refractory and wear-resistant coatings deposition; chemical synthesis; energy conversion; industrial, medical, and nuclear waste destruction; engine combustion enhancement; and exhaust gas pollutants clean up. Atmospheric plasmas are produced by applying DC or AC high voltage between two electrodes designed as cylindrical in shape for jets and planar for the dielectric barrier discharge systems. This review presents an overview of the use of atmospheric-pressure plasma devices and industrial processes carried out in several of these areas.

A comprehensive review of the pyrolysis process: from carbon nanomaterial synthesis to waste treatment

Thermally induced chemical decomposition of organic materials in the absence of oxygen is defined as pyrolysis. This process has four major application areas: (i) production of carbon materials, (ii) fabrication of pre-patterned micro and nano carbon-based structures, (iii) fragmentation of complex organic molecules for analytical purposes and (iv) waste treatment. While the underlying process principles remain the same in all cases, the target products differ owing to the phase and composition of the organic precursor, heat-treatment temperature, influence of catalysts and the presence of post-pyrolysis steps during heat-treatment. Due to its fundamental nature, pyrolysis is often studied in the context of one particular application rather than as an independent operation. In this review article an effort is made to understand each aspect of pyrolysis in a comprehensive fashion, ensuring that all state-of-the-art applications are approached from the core process parameters that influence the ensuing product. Representative publications from recent years for each application are reviewed and analyzed. Some classical scientific findings that laid the foundation of the modern-day carbon material production methods are also revisited. In addition, classification of pyrolysis, its history and nomenclature and the plausible integration of different application areas are discussed.

Bio-Mediated Synthesis of Nanomaterials for Electrochemical Sensor Applications

The bio-mediated nanomaterials have expected growing responsiveness due to an increasing requirement to develop naturally nonthreatening technologies in nanomaterial synthesis. Biotic ways to prepare nanomaterials through extracts from the plant (includes stems, leaves, flowers, and roots) and microorganisms were recommended as likely replacements for physical and chemical routes due to their solvent medium and environment eco-friendliness and nontoxicity. This chapter focuses on electrocatalyst prepared by various bio-mediated synthetic ways and used as a green and eco-friendly electrocatalyst to recognize extensive chemical and biologically essential molecules with improved selectivity and sensitivity with low detection limit. The bio-mediated nanocomposite formation processes and their unique properties surface functionalization and electron transfer mechanism discussed in connection with the design and fabrication of sensors. As a final point, the encounters and prospects in developing bio-mediated nanomaterials-based electrochemical sensing technology was outlined.

Synthesis, Optical Properties and Applications of Ternary Oxide Nanoparticles by a Microwave Technique

Nanocrystal preparation is in high demand due to the development of nanodevices. Nanostructures or microstructures of binary oxides such as TiO2, ZnO, and Al2O3 have been extensively prepared and studied. Synthesis of ternary oxide nanomaterials with controlled structures, morphologies, and sizes are of interest due to their potential applications in nanodevices caused by tunable energy level, bandgap, and structure. In this work, a solution-based method is used to prepare CaWO4 and LaPO4 ternary oxide nanomaterials by microwave technique. Controlled sizes and morphologies including nanorods and microspheres are synthesized by the microwave method, which is believed to be a facile and low-cost technique for the synthesis of ternary oxide nanomaterials. Furthermore, the (relatively) quick process enables high efficiency of the production. The structural and optical properties of the prepared nanomaterials are also investigated in this work. This work benefits nanomaterial synthesis for nanomanufacturing and applications in lighting and photodynamic activations as well as optical storage.

Preparation and characterization of Black titanium by chemical reduction of TiO2 and its photocatalytic activity

Background: Monitoring of the chemical synthesis of black titanium. Objective: In this study, we prepared a black titanium nanomaterial by chemical reduction (NaBH4 treatment). Control of the black TiO2 nanomaterial synthesis followed by a thermal analysis from 100°C to 400°C under azote atmosphere is presented. We used a commercial dye, Reactive Bezactiv Yellow (RBY) degradation, to examine the photocatalytic activity of the black titanium. Method: The thermal analysis of WT and a mixture of treated TiO4 (WT+NaBH2) was examined by thermogravimetric analysis (TGA). Results: A deformation of the crystalline lattice is extended beyond the entire visible spectrum. The thermal property reveals that the black titanium is more stable than the white titanium, and BT indicated a more photocatalytic performance than WT. Conclusion: We have successfully synthesized black titanium via chemical reduction employing a synthesis of white titanium. The thermal analysis reveals that BT has a high resistance than WT that offers a promising opportunity for several photocatalytic applications.