Abstract: A method of preparing titania nanotubes involves anodization of titanium in the presence of chloride ions and at low pH (1-7) in the absence of fluoride. The method leads to rapid production of titania nanotubes of about 25 nm diameter and high aspect ratio. The nanotubes can be organized into bundles and tightly packed parallel arrays. Inclusion of organic acids in the electrolyte solution leads to the incorporation into the nanotubes of up to 50 atom percent of carbon. In a two-stage method, a titanium anode is pre-patterned using a fluoride ion containing electrolyte and subsequently anodized in a chloride ion containing electrolyte to provide more evenly distributed nanotube arrays. The titania nanotubes have uses in composite materials, solar cells, hydrogen production, and as hydrogen sensors.

Abstract: A method of preparing titania nanotubes involves anodization of titanium in the presence of chloride ions and at low pH (1-7) in the absence of fluoride. The method leads to rapid production of titania nanotubes of about 25 nm diameter and high aspect ratio. The nanotubes can be organized into bundles and tightly packed parallel arrays. Inclusion of organic acids in the electrolyte solution leads to the incorporation into the nanotubes of up to 50 atom percent of carbon. In a two-stage method, a titanium anode is pre-patterned using a fluoride ion containing electrolyte and subsequently anodized in a chloride ion containing electrolyte to provide more evenly distributed nanotube arrays. The titania nanotubes have uses in composite materials, solar cells, hydrogen production, and as hydrogen sensors.

Abstract: A process for partially oxidizing alcohols such as methanol, comprising the steps of a) introducing into a reactor unit containing a solid acid catalyst amounts of alcohol and oxygen; and a supercritical fluid (such as SCF CO.sub.2) mobile phase; and b) partially oxidizing the alcohol to its corresponding ether, aldehyde, ester or acid. In an advantageous embodiment, methanol is oxidized using an aerogel acid catalyst to produce methyl ether.