Research Topics

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Metal-Organic Framework Materials

 

                                                                                                                                                 İlgili resim

 

Metal–organic frameworks (MOFs) are crystalline porous solids composed of a three-dimensional (3D) network of metal ions held in place by multidentate organic molecules. The spatial organization of these structural units leads to a system of channels and cavities in the nanometer length scale, analogous to that found in zeolites. Correct selection of the structural subunits and the way in which they are connected allows systematic modification of the pore structure of MOFs. Over the last decade, the elevated surface area and pore volume and the flexibility of pore design characteristic of MOFs have sparked research aimedmainly at preparing new MOF structures and studying their applications in gas storage and catalysis. Current projects in this realm include use of either neat MOF or metal nanoparticles hosted MOF materials as catalyst in various organic and inorganic catalytic transformations. 

 Colloidal Metal Nanoparticles

 

      

 

The colloidal monodispersed metal nanoparticles of less than 100 nm size have significant potential as new types of highly active and selective catalysts. Compared to their bulk-counterparts, colloidal metal nanoparticles have much higher surface-to-volume ratio, thus, larger fraction of catalytically active atoms on the surface, and these surface atoms of nanoparticles do not order themselves in the same way as those in bulk metal. In our group one of the active research fields is the synthesis of novel colloidal metal nanoparticles and their catalytic applications in various catalytic reactions.

 Supported Metal Nanoparticles

                                                                                                                                                                                       

                                                                                                                                                                     

                                                                                                                           

                                                                                                                     

It is well-known that, the agglomeration of initially well-dispersed colloidal metal nanoparticles throughout the catalytic runs in the reaction solution is still the most important problem in their catalytic applications. At this concern, the stabilization of nanoparticles by the framework of porous solid support materials seems to be one of the possible ways for preventing the agglomeration of nanoparticles in their catalytic use. Our approach centers on the use of porous solids with high surface areas as host materials to guest metal nanoparticles for different catalytic applications.

 

 Hydrogen Storage and Generation

                                                                                                                                                                                                                                                                                                                                                

                                                                                                                                              

                                                                                                                                                                              

Hydrogen is a globally accepted clean energy carrier, which could solve the world energy problem and reduce the environ-mental pollution originated from the fossil fuels as the hydrogen can be act as an environmentally friendly energy vector to end users when combined with proton exchange membrane (PEM) fuel cells. However, controlled storage and release of hydrogen are still technological barriers in the fuel cell based hydrogen economy. Among the various kinds of hydrogen storage materials, in our group we concentrated on formic acid, amine-boranes and hydrazine-borane as suitable hydrogen storage materials due to their high energy density, stability and non-toxicity.

Atomic Layer Deposition (ALD)

 

                                                                                                                                                     

 

Atomic layer deposition (ALD) is a promising synthesis strategy that is under development for producing metal nanoparticles on metal oxide supports. ALD is a thin film growth technique, which relies on self-limiting binary reactions between gaseous precursor molecules and a substrate to deposit uniform films in a layer-by-layer fashion. Unlike wet chemical synthesis methods, ALD involves only the nanoparticles precursors, thereby minimizing possible contamination from solvents and surfactants and allows conformal deposition on most substrates regardless of whether they are flat, porous, or have challenging three-dimensional topologies. In our group we are actively working on both synthesis and preventing of metal nanoparticles against to agglomeration and leaching.

 

Nanofluids

                                                                                                                                                                                    

                                                                                                                                                                                                             

 

Nanofluids (fluid containing nanoparticles) have novel properties that make them potentially useful in many applications in heat transfer including microelectronics, fuel cells, pharmaceutical processes, and hybrid-powered engines, engine cooling/vehicle thermal management, domestic refrigerator, chiller, heat exchanger, in grinding, machining and in boiler flue gas temperature reduction. They exhibit enhanced thermal conductivity and the convective heat transfer coefficient compared to the base fluid. Knowledge of the rheological behaviour of nanofluids is found to be critical in deciding their suitability for convective heat transfer applications. In our research group we investigate application of both supported and support-free nanoparticles in nanofluid systems.

  

Antibacterial Nanostructures

                                                                                                                                                                                    

                                                                                                                                                                         

Antibacterial agents are very important in the textile industry, water disinfection, medicine, and food packaging. Organic compounds used for disinfection have some disadvantages, including toxicity to the human body, therefore, the interest in inorganic disinfectants such as metal oxide nanoparticles is increasing. We mainly focuse on the properties and applications of inorganic nanostructured materials and their surface modifications, with good antimicrobial activity. Such improved antibacterial agents locally destroy bacteria, without being toxic to the surrounding tissue. We also provide an overview of opportunities and risks of using NPs as antibacterial agents. In particular, we discuss the role of different nanoparticle materials.