Method for preparing particulate metal oxide materials

A method for preparing a particulate metal oxide comprising fibers and/or particles having at least one-dimension that is within the subnanometer, nanometer, and/or micrometer size range;

• the method comprising the steps of:
• (a) preparing a solution of one or more metal salts and one or more polymers in a solvent in which the polymers and metal salts are soluble;
• (b) fabricating a precursor material comprising one or more thin films, fibers, or particles from the solution of step (a);
• wherein the precursor material comprises metal ions from the salts dispersed in an amorphous or partially crystalline matrix of the polymers;
• the metal ions are present in the precursor material in a ratio corresponding to the ratio of metal ions in the particulate metal oxide;
• the thin films have a thickness in the range of about 0.1 nm to about 100 µm;
• the fibers have a cross-sectional dimension in the range of about 0.1 nm to about 100 µm;
• and the and particles have a cross-sectional dimension in the range of about 0.1 nm to about 100 µm;
• (c) irradiating the precursor material with high energy pulsed-light flashes in an oxygen-containing atmosphere with one or more flashes of pulsed light at energy levels of about 0.3 to about 60 J/cm2 per pulse, at pulse durations in the range of about 0.01 to 10 ms, and a pulse repetition rate in the range of about 0.01 to about 10 Hz;
• and continuing the irradiation for a number of pulses in the range of 1 to 10000 pulses necessary to provide sufficient photon energy to oxidize and decompose the polymer in the precursor material, and oxidize the metal ions to form the particulate metal oxide.