TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Method: The plasma discharge has a power of 200-5000 W. The plasma discharge extends vertically downwards, and where the step of exposing the mixture to the plasma discharge for the first predetermined time period includes feeding the mixture into the plasma discharge reactor. The plasma discharge extends vertically upwards, and where the step of exposing the mixture to the plasma discharge for the first predetermined time period includes placing the mixture on a substrate (214) and exposing the substrate to the plasma discharge. The plasma discharge extends vertically downwards, and where the step of exposing the mixture to the plasma discharge for the first predetermined time period includes placing the mixture on a substrate and exposing the substrate to the plasma discharge. The first predetermined time period comprises 2-30 minutes. The method further comprises: contacting the transition metal oxide nanowires with an acid solution such that an alkali metal ion is exchanged for a hydrogen ion on each of the transition metal oxide nanowires; after contacting the transition metal oxide nanowires with the acid solution, exposing the transition metal oxide nanowires to the plasma discharge for a second predetermined time period to thermally anneal the transition metal oxide nanowires. Preferred Components: The transition metal is titanium, tungsten, cobalt or manganese. The metal oxide is titanium oxide, tungsten oxide, cobalt oxide or manganese oxide. The alkali metal compound comprises an alkali metal consisting of potassium, lithium or sodium. The alkali metal compound is: an alkali metal salt consisting of potassium chloride, lithium chloride or sodium chloride; or an alkali metal hydroxide consisting of potassium hydroxide, lithium hydroxide, or sodium hydroxide. The transition metal or transition metal oxide is a transition metal oxide consisting of titanium oxide, tungsten oxide, cobalt oxide, or manganese oxide, and the alkali metal compound comprises potassium chloride. The transition metal oxide is titanium oxide. The transition metal or transition metal oxide is provided in the form of a foil. The silica is silica powder. The means for generating an oxygen radical is a plasma discharge reactor. The lithium compound is lithium hydroxide. EXAMPLE - Microwave plasma reactor was capable of producing highly dense microwave plasma discharges at powers of 500 W to 3 kW at atmospheric conditions, and the plasma flame could be shaped vertically upwards or downwards depending upon the experimental requirements. A gaseous mixture of argon (21 pm), air (111 pm), and hydrogen (1000 sccm) was fed at the top of the reactor to ignite and maintain the plasma throughout the duration of the experiments. A 1x 1 cm piece of titanium foil was cut from a titanium foil (100x 100 mm, 0.5 mm thick) and was filed on both sides using a rectangular file. The filed titanium foil was then ultra-sonicated for 5 minutes to clean the surface. A small amount of Ti powder (65 mu m size) was then mixed with alkali metal salt crystals and sprinkled together on the top of the titanium foil, which was then carefully exposed to the plasma flame at power of 800-1000 W for 5 minutes. In direct gas phase synthesis experiments, metal or metal oxide powder mixed with alkali salt crystals was poured from the top of the reactor and collected at the bottom in a cup. The arsenic-synthesized material was then dipped in 1M hydrochloric acid solution for 1 hour for ion exchange, and was subsequently washed with de-ionized water and annealed by exposure to the plasma flame for 5 minutes to give the titania nanowires.