Highly dispersed Cr oxygenated species on Pt nanowire assemblies for enhanced electrocatalytic methanol oxidation

In this paper, the Cr oxygenated species dispersed on the Pt nanowire assemblies(PtCrOX NWs) were successfully prepared for methanol oxidation reaction by the metal precursor dilution strategy. Notably, PtCrOX NWs...

Single Step Laser-Induced Deposition of Plasmonic Au, Ag, Pt Mono-, Bi- and Tri-Metallic Nanoparticles

Multimetallic plasmonic systems usually have distinct advantages over monometallic nanoparticles due to the peculiarity of the electronic structure appearing in advanced functionality systems, which is of great importance in a variety of applications including catalysis and sensing. Despite several reported techniques, the controllable synthesis of multimetallic plasmonic nanoparticles in soft conditions is still a challenge. Here, mono-, bi- and tri-metallic nanoparticles were successfully obtained as a result of a single step laser-induced deposition approach from monometallic commercially available precursors. The process of nanoparticles formation is starting with photodecomposition of the metal precursor resulting in nucleation and the following growth of the metal phase. The deposited nanoparticles were studied comprehensively with various experimental techniques such as SEM, TEM, EDX, XPS, and UV-VIS absorption spectroscopy. The size of monometallic nanoparticles is strongly dependent on the type of metal: 140–200 nm for Au, 40–60 nm for Ag, 2–3 nm for Pt. Bi- and trimetallic nanoparticles were core-shell structures representing monometallic crystallites surrounded by an alloy of respective metals. The formation of an alloy phase took place between monometallic nanocrystallites of different metals in course of their growth and agglomeration stage.

Studies on Surface Plasmon Resonance of Murdannia loriformis Silver Nanoparticles

In this work, surface plasmon resonance (SPR) was investigated over the effect of concentration of metal precursor, concentration of reducing agent, reaction time and pH on formation of silver nanoparticles (AgNPs) using biological method. In this method, Murdannia loriformis extract (MLE) was used as reducing agent and silver nitrate as metal precursor. SPR of Murdania loriformis silver nanoparticles (MLE-AgNPs) was measured through UV-vis spectrophotometer over a range of 380 – 800 nm wavelength. It was found that, as the concentration of MLE, pH and reaction time increases, the SPR peak of MLE-AgNPs at 430 - 490 nm also increases. However, for effect of concentration of metal precursor, the result showed that SPR peak of MLE-AgNPs increases when 1 to 5 mM of silver nitrate was used but decreases for 10 and 15 mM. Significant of this study is to identify the optimum conditions for synthesis of MLE-AgNPs.

On the Importance of Considering Multinuclear Metal Sites in Homogeneous Catalysis Modeling

In this short review, we provide an account of a number of computational studies of catalytic reaction mechanisms carried out in our groups. We focus in particular on studies in which we came to realize during the course of the investigation that the active catalytic species was a bimetallic complex, rather a monometallic one as previously assumed. In some cases, this realization was in part prompted by experimental observations, but careful exploration based on computation of the speciation of the metal precursor also provided a powerful guide: it is often possible to predict that bimetallic species (intermediates or transition states) lie lower in free energy than a priori competitive monometallic species. In this sense, we argue that in organometallic catalysis, the rule whereby “two is better than one” turns out to be relevant much more often than one might expect.

Cobalt nanoparticle catalysed graphitization and the effect of metal precursor decomposition temperature

Porous carbon foams hold great promise for supercapacitors and next generation energy storage materials but greater control over the formation of the pore structure would aid the development of these...

Reactions of ruthenium cyclopentadienyl precursor in the metal precursor pulse of Ru atomic layer deposition

The elimination of Cp ligand on Ru(001) and (100) surfaces have high barriers and the reactions of hydrogen transfer are endothermic. The final terminations are 0.85 RuCp per nm2 on Ru(001) surface and 1.01 (Ru + RuCp2) per nm2 on Ru(100) surface.