Hakan Sert

New Pt(0) Nanoparticles as Highly Active and Reusable Catalysts in the C1–C3 Alcohol Oxidation and the Room Temperature Dehydrocoupling of Dimethylamine-Borane (DMAB)

New Pt(0) nanoparticles were easily and reproducibly prepared by the simultaneous reduction method using 1-butylamine (BA) and tributylamine (TBA) for the first time as capturing ligands at room temperature. X-ray diffraction, X-ray photoelectron microscopy and transmission electron microscopy measurements verify the formation of well-dispersed Pt(0) nanoparticles [~3.63 and ~3.98xa0nm for catalysts prepared using BA (catalyst I) and TBA (catalyst II), respectively] on an activated carbon surface. The catalytic performances of these nanoparticles in terms of activity, isolability and reusability were investigated for both alcohol oxidation and the dehydrocoupling of dimethylamine-borane (DMAB). These nanoparticles were shown to be as active and reusable heterogeneous catalysts even at room temperature. The prepared catalysts can catalyze the dehydrogenation of DMAB with one of the highest known activities at room temperature and also C1–C3 alcohol oxidation with very high electrochemical activities.

Rapid, sensitive, and reusable detection of glucose by highly monodisperse nickel nanoparticles decorated functionalized multi-walled carbon nanotubes

Addressed herein, functionalized multi-walled carbon nanotube (MWCNT) supported highly monodisperse nickel nanoparticles modified on glassy carbon electrode (Ni@f-MWCNT/GCE) were synthesized through microwave assisted method and examined for non-enzymatic glucose sensing in ionic liquids by cyclic voltammetry and chronoamperometry. The results of Ni@f-MWCNT/GCE electrode were compared with Ni NPs/GCE electrode and the results revealed that f-MWCNTs increased the electrocatalytic properties of Ni nanoparticles regarding glucose oxidation. They also demonstrated a good linear span of 0.05-12.0mM and a detection boundary of 0.021µM. Specifically, in the amperometric signal of the electrodes after 200th cycles, no major change was observed. This non-enzymatic glucose sensor presents one of the record electrocatalytic activity, stability and response towards glucose under the optimized situations. As a result, prepared novel Ni@f-MWCNT/GCE was utilized to detect glucose in real serum species.

Monodispersed palladium–cobalt alloy nanoparticles assembled on poly( N -vinyl-pyrrolidone) (PVP) as a highly effective catalyst for dimethylamine borane (DMAB) dehydrocoupling

Herein we report the fabrication of monodispersed poly(N-vinyl-2-pyrrolidone) supported palladium–cobalt nanomaterials (3.45 ± 0.36 nm) and their outstanding efficiency as catalysts in dimethylamine-borane dehydrogenation. By the use of an ultrasonic double reduction method, palladium and cobalt cations were co-reduced in PVP solution and then the prepared nanocatalysts were characterized by UV-Vis, XRD, XPS and HR-TEM-EDX analyses. The nanocatalysts could be easily reused, and at extremely low concentrations and temperature they showed record catalytic activity, giving the best catalytic performance yet with a very high turnover frequency (330.94 h−1) and a low Ea value of 50.78 ± 2 kJ mol−1 for DMAB dehydrocoupling.

Monodisperse Mw-Pt NPs@VC as Highly Efficient and Reusable Adsorbents for Methylene Blue Removal

Addressed herein, monodisperse Vulcan carbon supported Pt nanoparticles (Mw-Pt NPs@VC) have been reproducibly synthesized using the microwave assisted method and their application for methylene blue (MB) removal from aqueous solutions was investigated through the adsorption mechanism. The prepared nanomaterials were characterized by X-ray diffraction, transmission electron microscopy, high resolution transmission electron microscopy and X-ray photoelectron spectroscopy. All results show that highly crystalline and colloidally stable nanoparticles have been formed and Mw-Pt NPs@VC were found to be one of the the most active catalyst. The results showed that the Mw-Pt NPs@VC nanoparticles had remarkable MB adsorption capacity of 271.15xa0mg/g. The equilibrium for MB adsorption was attained in ∼55xa0min. Moreover, Mw-Pt NPs@VC is a reusable and promising material for MB removal since it preserves 95.6xa0% of its initial efficiency after six successive cycles of adsorption–desorption.

A Novel Triple-Responsive Hydrogels Based on 2-(Dimethylamino) Ethyl Methacrylate by Copolymerization With 2-(N-morpholino) Ethyl Methacrylate

A novel triple responsive copolymer hydrogels composed of 2-(dimethylamino) ethyl methacrylate and 2-(N-morpholino) ethyl methacrylate monomers were prepared through free radical polymerization. The structure and morphology of the hydrogels were examined by using infrared spectroscopy (ATR-IR) and scanning electron microscopy (SEM). It was found that poly (DMAEMA-co-MEMA) hydrogels exhibited pH-dependent smart swelling and shrinking behavior in buffer solutions which is ascribed to the protonation/deprotonation of the tertiary amine pendant groups of both monomers. The copolymerization of more hydrophobic MEMA monomer with hydrophilic DMAEMA monomer created associated micro domain in the hydrogel structure which is able to induce reversible phase transition of the hydrogel. Therefore, poly (DMAEMA-co-MEMA) hydrogels displayed rapidly responses to the increasing temperature and divalent salt effects by shrink-type behavior. Such a multi-responsive network structure would be very beneficial for biomedical applications.