High-quality nanoscaled fluorine and nitrogen co-doped anatase-phase titanium oxide can be obtained from the conversion of ammonium oxotrifluorotitanate by thermal treatment. The photocatalytic activity of titanium oxide treated at 800 degrees C shows the highest photocatalytic activity and is about 1.31 times of P-25 due to higher fluorine and nitrogen doping. The heterojunction of zinc sulfide/titanium oxide prepared by metallorganic vapor-phase epitaxy shows 1.51 times the photocatalytic activities of commercial P-25. Both nanoscaled titanium oxide and zinc sulfide/titanium oxide heterojunction show a proportional relationship between carrier lifetime and photocatalytic activity. (c) 2007 The Electrochemical Society.