The strong metal-oxide interaction of platinum nanoparticles (PtNPs) deposited on two types of cobalt oxides, CoO and Co3O4, was investigated using CO oxidation. Two different sizes of PtNPs as well as arc-plasma-deposited (APD) PtNPs without a capping layer were used to reveal the effect of metal-oxide interfaces on catalytic activity. An enhanced catalytic activity was observed on the PtNPs on the Co3O4 substrate, which was ascribed to the reducible support and to the interfacial sites.
View Article and Find Full Text PDFHot electrons generated on metal catalysts influence atomic and molecular processes, leading to hot electron-driven catalytic reactions. Here, we show the acceleration of electrocatalytic hydrogen evolution caused by internal injection of hot electrons on Pt/Si metal-semiconductor electrodes. When a forward bias voltage is applied to the Pt/Si contact, hot electrons are injected.
View Article and Find Full Text PDFThe use of hot carriers generated from the decay of localized surface plasmon resonance in noble metal nanoparticles is a promising concept for photocatalysis. Here, we report the enhancement of photocatalytic activity by the flow of hot electrons on TiO nanotube arrays decorated with 5-30 nm Au nanoparticles as photoanodes for photoelectrochemical water splitting. This enhanced photocatalytic activity is correlated to the size of the Au nanoparticles, where higher oxygen evolution was observed on the smaller nanoparticles.
View Article and Find Full Text PDFIn heterogeneous catalysis, the role of the interface between a metal and a metal oxide in deciding catalytic performance has remained a long-standing question. Out of many molecular-scale factors that affect the properties of metal-oxide interfaces, doping or impurities in the oxides can result in excess charge carriers or oxygen vacancies on the oxides, which lead to a change in catalytic activity. For a model system with a tunable dopant, we employed Pt nanoparticles with Fe doping.
View Article and Find Full Text PDFUnderstanding the role of electronically nonadiabatic interactions during chemical reactions on metal surfaces in liquid media is of great importance for a variety of applications including catalysis, electrochemistry, and environmental science. Here, we report the design of an experimental apparatus for detection of the highly excited (hot) electrons created as a result of nonadiabatic energy transfer during the catalytic decomposition of hydrogen peroxide on thin-film metal-semiconductor nanodiodes. The apparatus enables the measurement of hot electron flows and related phenomena (e.
View Article and Find Full Text PDFActivation-induced cytidine deaminase (AID) is the only enzyme that has been suggested as a putative DNA demethylase in mammals. However, very little is known about AID function as DNA demethylase of bovine differentiated cells toward pluripotent state. To investigate the effect of AID on DNA demethylation, bovine AID complementary DNAs were transfected into bovine differentiated cells, which were mostly methylated in the promoter regions of pluripotency genes.
View Article and Find Full Text PDFThe study of energy and charge transfer during chemical reactions on metals is of great importance for understanding the phenomena involved in heterogeneous catalysis. Despite extensive studies, very little is known about the nature of hot electrons generated at solid-liquid interfaces. Herein, we report remarkable results showing the detection of hot electrons as a chemicurrent generated at the solid-liquid interface during decomposition of hydrogen peroxide (H2 O2 ) catalyzed on Schottky nanodiodes.
View Article and Find Full Text PDFDue to the tunability of the physical, electrical, and optical characteristics of graphene, precisely controlling graphene oxidation is of great importance for potential applications of graphene-based electronics. Here, we demonstrate a facile and precise way for graphene oxidation controlled by photoexcited charge transfer depending on the substrate and bias voltage. It is observed that graphene on TiO2 is easily oxidized under UV-ozone treatment, while graphene on SiO2 remains unchanged.
View Article and Find Full Text PDFJ Phys Condens Matter
June 2016
Hot electrons and surface-plasmon-driven chemistry are amongst the most actively studied research subjects because they are deeply associated with energy dissipation and the conversion processes at the surface and interfaces, which are still open questions and key issues in the surface science community. In this topical review, we give an overview of the concept of hot electrons or surface-plasmon-mediated hot electrons generated under various structural schemes (i.e.
View Article and Find Full Text PDFEngineering metal-oxide interfaces in TiO2/nanoporous (np) Au inverse catalysts results in enhancement of H2 oxidation activity. While the intrinsic activity of the novel np-Au prepared from a Au-Si alloy is low, the activity increased as the weight fraction of the TTIP (amount of TiO2) was increased to 0.5 weight%.
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