Waseda University

About: Waseda University is a education organization based out in Tokyo, Japan. It is known for research contribution in the topics: Large Hadron Collider & Catalysis. The organization has 24220 authors who have published 46859 publications receiving 837855 citations. The organization is also known as: Waseda daigaku & Sōdai.

Mesoporous Metallic Cells: Design of Uniformly Sized Hollow Mesoporous Pt–Ru Particles with Tunable Shell Thicknesses

Abstract: A new class of hollow mesoporous Pt-Ru and Pt particles with uniform size, named 'mesoporous metallic cells', are synthesized through a dual-templating approach using colloidal silica particles and non-ionic surfactants. To realize the full potential of mesoporous metals as electrocatalysts, the shell thicknesses, compositions, and hollow cavity sizes are precisely controlled.

First Order Phase Transition Resulting from Finite Inertia in Coupled Oscillator Systems

Abstract: We analyze the collective behavior of a set of coupled damped driven pendula with finite (large) inertia, and show that the synchronization of the oscillators exhibits a first order phase transition synchronization onset, substantially different from the second order transition obtained in the case of no inertia. There is hysteresis between two macroscopic states, a weakly and a strongly coherent synchronized state, depending on the coupling and the initial state of the oscillators. A self-consistent theory is shown to determine these cooperative phenomena and to predict the observed numerical data in specific examples. [S0031-9007(97)02614-8]

Progress in nickel chalcogenide electrocatalyzed hydrogen evolution reaction

Abstract: Electrochemical water splitting powered by electrical energy derived from renewable sources is a green and faster way of producing bulk hydrogen with the highest purity. Unfortunately, the cost-inefficiency associated with energy loss (as overpotential) and costs of electrode materials have been forbidding this technology to surpass the currently dominant industrial process (steam reforming of hydrocarbons). With the recent evolution of transition metal chalcogenides, efficient commercial electrochemical water splitting is not too far. Transition metal chalcogenides are better in the hydrogen evolution reaction (HER) than pristine metals as they have negatively polarized chalcogenide anions with relatively lower free energy for proton adsorption. Moreover, chalcogenides are relatively easy to prepare and handle. Several metal chalcogenides have been reported with good HER activity among which Ni chalcogenides are reported to be exceptional ones. In recent years, growth of the nickel chalcogenide catalysed HER is massive. This review is devoted to bringing out a comprehensive understanding of what had happened in the recent past of this field with highlights on future prospects. In addition, we have also briefed the key physico-chemical properties of these materials and highlighted what one should anticipate while screening an electrocatalyst for electrochemical water splitting.

Facile solution synthesis of Ag@Pt core–shell nanoparticles with dendritic Pt shells

Abstract: Ag@Pt nanoparticles with various dendritic Pt shells were successfully synthesized by using nonionic surfactants at room temperature. Our recent study demonstrated that the addition of nonionic surfactant plays an important key role in the synthesis of dendritic Pt nanostructures (J. Am. Chem. Soc., 2010, 132, 13636). Here we extend this synthetic concept to prepare various Ag@Pt nanoarchitectures. The different nanostructured Pt shells on the Ag core were confirmed by ultraviolet-visible absorption spectroscopy and transmission electron microscopy. As a preliminary electrochemical application, the obtained Ag@Pt nanostructures were applied in the methanol oxidation reaction (MOR) in 0.5 M H2SO4 solution containing 0.5 M methanol. The Ag@Pt nanoparticles with thin dendritic Pt shells show superior CO-tolerance performance with a If/Ib value reaching 3.71. Our Ag@Pt nanostructures with good CO tolerant activity will be prominent catalysts for MOR.