Keiji Nagai

Prof. Keiji Nagai

orcid

Research Focus & Metrics

Academic Career Length

32Years (1995-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 March 2018 in Physics of Plasmas
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Journal Article
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KNKeiji Nagai
Keiji Nagai
CMChristopher Musgrave
Christopher Musgrave
WNWigen Nazarov
Wigen Nazarov
This review describes and categorizes the synthesis and properties of low density porous materials, which are commonly referred to as foams and are utilized for laser plasma experiments. By focusing a high-power laser on a small target composed of these materials, high energy and density states can be produced. In the past decade or so, various new target fabrication techniques have been developed by many laboratories that use high energy lasers and consequently, many publications and reviews followed these developments. However, the emphasis so far has been on targets that did not utilize low density porous materials. This review therefore, attempts to redress this balance and endeavors to review low density materials used in laser plasma experiments in recent years. The emphasis of this review will be on aspects of low density materials that are of relevance to high energy laser plasma experiments. Aspects of low density materials such as densities, elemental compositions, macroscopic structures, nanostructures, and characterization of these materials will be covered. Also, there will be a brief mention of how these aspects affect the results in laser plasma experiments and the constrictions that these requirements put on the fabrication of low density materials relevant to this field. This review is written from the chemists' point of view to aid physicists and the new comers to this field.

25 January 2021 in Catalysts
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Journal Article
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Prabhakarn ArunachalamPrabhakarn Arunachalam
Prabhakarn Arunachalam
KNKeiji Nagai
Keiji Nagai
MABROOK SALEH AmerMABROOK SALEH Amer
MABROOK SALEH Amer
Mohamed Ali GhanemMohamed Ali Ghanem
Mohamed Ali Ghanem
Jothi Ramalingam RajabatharJothi Ramalingam Rajabathar
Jothi Ramalingam Rajabathar
Abdullah Mohammed Al-MayoufAbdullah Mohammed Al-Mayouf
Abdullah Mohammed Al-Mayouf
Visible-light-driven photoelectrochemical (PEC) and photocatalytic water splitting systems featuring heterogeneous semiconductor photocatalysts (oxynitrides, oxysulfides, organophotocatalysts) signify an environmentally friendly and promising approach for the manufacturing of renewable hydrogen fuel. Semiconducting electrode materials as the main constituents in the PEC water splitting system have substantial effects on the device’s solar-to-hydrogen (STH) conversion efficiency. Given the complication of the photocatalysis and photoelectrolysis methods, it is indispensable to include the different electrocatalytic materials for advancing visible-light-driven water splitting, considered a difficult challenge. Heterogeneous semiconductor-based materials with narrower bandgaps (2.5 to 1.9 eV), equivalent to the theoretical STH efficiencies ranging from 9.3% to 20.9%, are recognized as new types of photoabsorbents to engage as photoelectrodes for PEC water oxidation and have fascinated much consideration. Herein, we spotlight mainly on heterogenous semiconductor-based photoanode materials for PEC water splitting. Different heterogeneous photocatalysts based materials are emphasized in different groups, such as oxynitrides, oxysulfides, and organic solids. Lastly, the design approach and future developments regarding heterogeneous photocatalysts oxide electrodes for PEC applications and photocatalytic applications are also discussed.

4 September 2009 in ACS Applied Materials & Interfaces
Verified
Journal Article
Closed access
HYHan Yang
Han Yang
KNKeiji Nagai
Keiji Nagai
TAToshiyuki Abe
Toshiyuki Abe
HHHirofumi Homma
Hirofumi Homma
TNTakayoshi Norimatsu
Takayoshi Norimatsu
RRRamasamy Ramaraj
Ramasamy Ramaraj

19 May 2011 in ChemSusChem
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Journal Article
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KNKeiji Nagai
Keiji Nagai
TAToshiyuki Abe
Toshiyuki Abe
YKYumi Kaneyasu
Yumi Kaneyasu
YYYuzuri Yasuda
Yuzuri Yasuda
IKIchirou Kimishima
Ichirou Kimishima
HIHiroshi Imaya
Hiroshi Imaya

23 May 2016 in Chemical Communications
Verified
Journal Article
Open access
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TAToshiyuki Abe
Toshiyuki Abe
KFKatsuma Fukui
Katsuma Fukui
YKYuto Kawai
Yuto Kawai
KNKeiji Nagai
Keiji Nagai
HKHideki Kato
Hideki Kato
This study examined a water-splitting system comprising a TiO2 photoanode and an organo-photocathode consisting of a p–n bilayer.

27 March 2004 in Fusion Science and Technology
Verified
Journal Article
Closed access
KNKeiji Nagai
Keiji Nagai
TNTakayoshi Norimatsu
Takayoshi Norimatsu
YIYasukazu Izawa
Yasukazu Izawa
The present report describes ultralow density (2~10 mg/cm3) hydrocarbon plastic (CH2) foams with a controllable micro- or nano-meter-sized lamella structure. These foams are prepared from a poly(4-methyl-1-pentene) gel with hexanol and butanol derivatives by extraction using supercritical fluid CO2. Their intended use is in laser-plasma experiments and as a laser-plasma X-ray source. Their microstructure approached to nanometer and was varied using different alcohols. The finest ultralow density foam was prepared from 2-butanol gel.