Patent ID: 8349147

Claim:
A method for forming a photocatalytic apatite film, comprising: preparing powder of photocatalytic apatite by first preparing an aqueous solution containing a calcium supplier, a titanium supplier that provides titanium ions in the aqueous solution, a phosphate supplier and an alkali aqueous supplier to supply hydroxyl groups, subsequently causing the aqueous solution of the calcium supplier, the titanium supplier, the phosphate supplier and the hydroxyl groups to undergo co-precipitation for generating calcium hydroxyapatite wherein part of calcium is substituted with titanium, and then drying the generated titanium-substituted calcium hydroxyapatite to provide the powder of photocatalytic apatite, a proportion of titanium in combined calcium and titanium in the photocatalytic apatite is from 3 to 11 mol % as represented by an equation of Ti/(Ti+Ca) being from 0.03 to 0.11 molar ratio; producing a sputtering target by sintering the powder of photocatalytic apatite, and sputtering, using said sputtering target, to form a photocatalytic apatite film on a substrate, wherein the powder of photocatalytic apatite is fired at 500 to 900° C. to increase a crystallinity of the photocatalytic apatite before the producing of the sputtering target.