Hydrothermal Synthetic Routes

Inorganic nanotubes, particularly oxide nanotube structures, have been synthesized via chemical routes without the use of a sacrificial template or an additional deposition process. Hydrothermal and/or solvothermal synthetic methods are very simple means of producing nanotube structures. Hydrothermal synthesis is usually accomplished at a high pressure and high temperature using an autoclave containing aqueous solutions that consist of an inorganic precursor 

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Hydrothermal Synthetic Route in the Clear Homogeneous System... 

Two Silica Sources Synthetic Route in the Hydrothermal Crystallizations... 

Finally, the use of various synthetic routes, including the sol-gel process [122], rheological phase [123], predpitation/decomposition [124], hydrothermal [125] sonochemical [126] and combustion reactions [121], are all currently being widely investigated for the production of nanoionic materials for use in lithium ion batteries. 

Although very promising, these catalysts would however benefit from an increased level of conversion and selectivity. Currently, these mixed oxide catalysts are prepared either by commercial dry-up or lab-scale hydrothermal synthesis which usually leads to low surface area materials (<20 m /g) [6]. These catalysts exhibit a rather good selectivity for small space velocities, but the improvement of the catalytic performance by increasing the productivity remains a challenge. Whilst much research effort has been spent on optimisation of catalyst performance, less attention has been drawn to problems concerning catalyst preparation. Therefore, the identification of new synthetic routes for improvement of these parameters is more than ever a matter of interest. 

We are interested in vanadoborate cluster materials both as precursors to porous solids and as a new class of molecular magnets. We have synthesized a variety of vanadoborate cluster compounds 1-7, primarily by use of two different synthetic routes. The first involves hydrothermal synthesis, using sodium tetraborate ( borax ) as the boron source and the second uses molten boric acid as the reaction medium. In general anionic clusters are found. Herein we report that these have novel electronic and bonding arangements which affect their magnetic behaviour and also that they may be cross-linked together by metal centers such as Cd to form stable microporous phases. 

During the last few years, different synthetic procedures have been reported for the synthesis of magnetic nanoparticles. These methods include co-precipitation, thermal decomposition and/or reduction, microemulsion synthesis, and hydrothermal synthesis. Despite poor shape control and quite polydisperse particles, co-precipitation is probably the simplest synthetic route. By contrast, thermal decomposition is experimentally more demanding but affords the best results in... 

There are various routes of hydrothermal crystallisation such as the ionothermal synthetic route, micro-emulsion-based hydrothermal route, dry gel conversion synthetic route, solvo-thermal S5mthetic route and so forth, which can be studied. 

Nanostructured materials have attracted great interest for many different applications, due to their unusual or enhanced properties compared with bulk materials [9-12]. An example of enhanced property of nanomaterials producing ad-value is the ionic conductivity. Therefore, the investigation of the nanostructured solid conductors, also known as nanoionics, has recently become one of the hottest fields of research. These nanomaterials can be used for advanced energy conversion and storage applications, such as SOFCs. Various synthetic routes, such as thermal evaporation [13], wet chemical processes including coprecipitation [14], the modified sol-gel method [15], the hydrothermal process [11,16], mixing freeze-dried precursors [17], or the combustion [18], have already been developed to produce solid electrolytes composed from nanosized crystallites. 

Many researchers have identified the difference in the presence of hot spots (which locally enhance or promote some selected reactions or transformations). The narrow temperature distribution obtained by simulation can justify the formation of nanoparticles (having a narrower particle size distribution) with respect to conventionally heated synthetic routes in case of nucleation and growth of nanoparticles (microwave hydrothermal synthesis). The large-scale production of nanoparticles requires the development of microwave reactors, which can reflect the laboratory temperature profile homogeneity. It will provide a new dedicated eontinuous-flow reactor, made of two twin prismatic applicators for a microwave-assisted process in aqueous solution. The reactor can produce upto 1000 L/day of nanoparticles eolloi-dal suspension at ambient pressirre and relatively low temperature and henee, it ean be considered a green chemistry approach. 

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