Layered inorganic solids, such as layered clay minerals and graphite, are composed of nanometer-thick layers assembled as alternating layer-by-layer manner. The interlayer can expand to accommodate guest species to give intercalation compounds. The interlayer reactivity (ion exchange, hydrogen bonding, redox etc.) of layered inorganic solids has been utilized for such applications as battery and adsorption. The layered materials and the intercalation compounds have been used as advanced materials as catalyst, catalyst support, adsorbent, electronic device, and drug carriers. Layered transition metal oxides are class of materials characterized by their useful electronic, magnetic, optical and catalytic properties Titanium oxide based layered materials have been synthesized and their ion exchange, electric and optical properties have been investigated so far. Here, some our previous studies on lepidocrocite- type layered titanates is introduced.
|Lepidocrocite-type layered titanates are shown as A x Ti 2-yMyO4 , which are composed of titanate nanosheets and alkali metal ions in the interlayer space. The composition of the lepidocrocite-type layered titanate is versatile resulting in the varied swelling ability and ion exchange ability. Therefore, we have been interested in the preparation and application of layered titanates.|
We have been investigating the photocatalytic performance of the layered titanates. Gold nanoparticle supported titanate was used for the oxidation of aqueous benzene to phenol, which is one of the most important chemical reaction in industry, with very high yields and efficiency. The molecular selective (enzymatic) photocatalytic decomposition of organics in water was also developed by the careful tuning of the interlayer reactivity. The photosensitization of layered titanate for visible light induced water splitting was also achieved in our laboratory.
The properties of layered titanate are modified by functionalization through cation exchange, grafting of organic functionality, and nanoparticles immobilization. Ruthenium complex was attached on surface of layered titanate as a sensitized layered titanate to produce hydrogen from water by visible light irradiation.