Transition metal nanoparticles applications

Although random and irregular type GaN nanorods have been prepared by using transition metal nanoparticles, such as Ni, Co, and Fe as catalysts and carbon nanotubes as the template, the preparation of controllable regular array of strai t GaN nanorods has not yet been reported. Fabrication of well-ordered nano-structures with high density is very important for the application of nano-structures to practical devices. 

Transition metal nanoparticles have attracted great attention due to their unique size-dependent properties and applications in diverse areas, including magnetic storage materials, catalysis, sensors and drug delivery. Depositions of various Pt-containing alloys are summarized in Table 2. Particularly, chemically synthesized transition metal alloy... 

As delineated in the Introduction, numerous research groups have focused on the preparation and application of transition metal nanoparticles in the zerovalent form during the last two decades but, parallel to this development, research in the area of nanosized metal oxides has also increased. The areas of application of metal oxide nanoparticles range from catalysis [4] to semiconductors (e.g., ZnO, ZnS, CdSe) [5]. In the area of heterogeneous catalysis, many different preparative methods have been described [4], Other methods are based on the hydrolysis of transition metal salts in microemulsions [3-8], These and other approaches have been reviewed and will not be specifically treated here. Rather, the main focus is on the author s own research. 

Transition metal nanoparticles have attracted a great deal of attention over the last 10 years. Their preparation, structure determination, and application are topics of current interest. Their catalytic properties have led to interesting applications. Because these are in fact ligand-free catalysts, high reactivity is a common feature... 

Soluble transition metal nanoparticles have attracted increasing attention in recent years and their preparation, structural characterization, and application in alternative solvents are under intense scrutiny [25]. While it is likely that a number of the molecular hydrogenation catalysts are actually precursors to nanoparticle catalysts, because of the reducing environment generated under high pressures of hydrogen, several studies comprising the application of deliberately prepared nanoparticle catalysts in ILs have been reported. Hydrated rhodium(III) chloride, RhClj 3 H2O,... 

The development of nanotechnology was one of the important field processes which plays an important and higher-impact role in the various biological applications (Anthony et al., 2014). Nanoparticles can act as an intermediate between atom properties and bulk materials (Madhumitha et al., 2015). Among nanoparticles, the transition metal nanoparticles have fascinated researchers all over globe due to their role in various application fields, such as chemistry, physics, biotechnology, catalysis, electronics, and optoelectronics (Otari et al., 2014 Roopan et al., 2014). Nowaday s transition metallic nanoparticles play a successful and... 

The consumption of drug and depositing of side effects in the morbid region without causing any high dosage value of synthesized nanoparticles resulted in low cost with selectively high approaches. Some potentially important applications include cancer treatment with transition metal nanoparticles. 

This chapter unearthed a brief overview of the current research activities about the transition metal nanoparticles synthesized by marine microbial sources followed by discussions of green synthesis of nanoparticles. The chapter concluded on the marine microbial sources in the preparation of transition metallic nanoparticles and also applications toward various biological activities which can facilitate researchers to work on marine microbial preparations of nanoparticles in the future. There has been superior development updated in the field of microorganism-mediated transition metal nanoparticle synthesis and various apphcation fields like biological systems, medicinal properties etc., even though much more work is needed for green synthesis of nanoparticles using several microbial sources which remain... 

Single step synthesis of transition metal nanoparticles in aqueous phase for catalytic applications... 

The electrical, magnetic, optical, and catalytic properties of transition metal nanoparticles differ decisively from those of the bulk phase. The peculiar effects of nanoparticle size, shape, and electronic structure are of interest both from the perspective of fundamental research and applications in energy research (Roduner, 2006 Yaca-man et al., 2001). Specific phenomena at particle sizes below 2 nm arise from the confinement of (quasi)-free electrons and the increasingly discrete nature of the electronic structure (Halperin, 1986). In electrocatalysis, the primary interests are to understand (i) the classical effects of atom arrangement and (ii) the heterogeneous electronic structure at the nanoparticle surface, controlling interfacial adsorption and charge transfer phenomena. 

As described in the Sect. 3.3, transition metals are conjugated with n-conjugated polymer like polyanilines. The transition metals can be extended to the transition metal nanoparticles (NPs). The resulting hybrids of metal NPs and polyanilines are expected to be of their potential applicability as electronic devices, chemical sensors, and catalysts. The NPs with small size and high surface-to-bulk ratio exhibit advantages compared with the bulk materials in the catalytic applications [73]. Therefore, the smaller and well-dispersed NPs are desired. 

The application of ly transition metal carbides as effective substitutes for the more expensive noble metals in a variety of reactions has hem demonstrated in several studies [ 1 -2]. Conventional pr aration route via high temperature (>1200K) oxide carburization using methane is, however, poorly understood. This study deals with the synthesis of supported tungsten carbide nanoparticles via the relatively low-tempoatine propane carburization of the precursor metal sulphide, hi order to optimize the carbide catalyst propertira at the molecular level, we have undertaken a detailed examination of hotii solid-state carburization conditions and gas phase kinetics so as to understand the connectivity between plmse kinetic parametera and catalytically-important intrinsic attributes of the nanoparticle catalyst system. 

Application of small metal particles has attracted the attention of the scientists for a long time. As early as in the seventies Turkevich already prepared mono-dispersed gold particles [19], and later, using molecular transition metal carbonyl clusters [20], the importance of small nanoparticles increased considerably. One of the crucial points is whether turnover frequency measured for a given catalytic reaction increases or decreases as the particle size is diminished. 

In materials chemistry, nanoparticles of noble metals are an original family of compounds. Well-defined in terms of their size, structure and composition, zero-valent transition-metal colloids provide considerable current interest in a variety of applications. Here, the main interest is their application in catalysis. Zerovalent nanocatalysts can be generated in various media (aqueous, organic, or mixture) from two strategic approaches according to the nature of the precursor, namely (i) mild chemical reduction of transition-metal salt solutions and (ii) metal atom... 

Recently, microgel-stabilized, size-controlled metal nanoclusters have found promising applications in the field of catalysis. In particular, microgel systems can work as active carriers for the metal nanoparticles, which allows us to modulate the catalytic activity of nanoparticles by a thermodynamic transition that takes place within the carrier system [24, 69], The principle is shown in Fig. 8 Metallic... 

All results reviewed herein demonstrate that the microgel particles may serve as nanoreactors for the immobilization of catalytically active nanostructures, namely for metal nanoparticles and enzymes. In both cases, the resulting composites particles are stable against coagulation and can be easily handled. Moreover, the catalytic activity of metal nanoparticles can be modulated through the volume transition that takes place within the thermosensitive microgel carrier system. Similar behavior has been also observed for the temperature dependence of enzymatic activity. Thus, the microgel particles present an active carrier system for applications in catalysis. 

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