Synthesis of NiO-loaded KTiNbO5 photocatalysts by a novel polymerizable complex method

Hiroyuki Takahashi, Masato Kakihana, Yohichi Yamashita, Kiyohide Yoshida, Shigeru Ikeda, Michikazu Hara, Kazunari Domen

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48 Citations (Scopus)


A polymerizable complex (PC) technique was utilized to prepare high-purity stoichiometric KTiNbO5 at reduced temperatures. Heating of a mixed solution of citric acid (CA), ethylene glycol (EG), and K, Ti and Nb ions with a molar ratio of CA:EG:K:Ti:Nb = 15:60:1:1:1 at 130°C produced a yellowish transparent polymeric gel without any precipitation, which after pyrolysis at 350-400°C was converted to a powder precursor for KTiNbO5. The complete formation of KTiNbO5 occurred when the powder precursor was heat-treated at 700°C for 2 h in static air. KTiNbO5 via the PC route, combined with NiO, showed more than ten times larger photocatalytic activities for the decomposition of water compared with those for a sample prepared at 1100°C by the conventional solid-state reaction method. The difference in the photocatalytic activities between the two samples was basically understood in terms of the difference in the surface areas. A partial loss of potassium was likely in the host KTiNbO5 material prepared by the high-temperature solid-state reaction method, which was supposed to be a factor altering the surface structure, thus influencing the overall photocatalytic activity of potassium titanoniobates.

Original languageEnglish
Pages (from-to)77-81
Number of pages5
JournalJournal of Alloys and Compounds
Issue number1-2 Complete
Publication statusPublished - 1999 Jun 30
Externally publishedYes

ASJC Scopus subject areas

  • Mechanics of Materials
  • Mechanical Engineering
  • Metals and Alloys
  • Materials Chemistry


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