Sodium　titanate　nanowires　(STNWs),　a　stable　and　easily　handled　precursor,　were　used　for　the　shape　controlled　synthesis　of　TiO2.　By　varying　the　composition　of　the　reaction　solutions,　the　morphology　of　TiO2　could　be　readily　controlled　by　the　hydrothermal　treatment　of　the　STNWs.　Three　different　shapes　of　TiO2:　nanospindles,　hollow　microspheres,　and　one　dimensional　chain-like　aggregates,　were　prepared　without　using　any　templates　by　adding　a　small　volume　of　HF　(1　mL)　or　(and)　H2O2　(5　mL)　to　the　hydrothermal　solutions.　The　structures,　textures,　morphologies,　optical　properties,　adsorption　capacities,　and　photocatalytic　activities　of　the　samples　were　carefully　investigated.　Chain-like　TiO2　aggregates　showed　the　highest　photocatalytic　performance　for　the　degradation　of　methyl　orange.　A　＂dissolution-nucleation＂　process　was　proposed　for　the　transformation　of　STNWs　to　nanospindles　and　hollow　microspheres,　while　a　topochemical　reaction　process　was　described　for　the　formation　of　the　chain-like　TiO2　aggregates.　The　dissolution　of　STNWs,　and　the　nucleation　and　growth　of　TiO　2　were　affected　by　the　additions　of　H2O2　and　HF.　H2O2　benefits　the　crystallization　of　TiO2,　while　HF　favors　the　formation　of　plate-like　particles　and　surface　fluorination.　The　impact　of　these　roles　on　the　morphologies,　surface　structures,　and　photocatalytic　behaviors　of　the　prepared　TiO2　samples　was　prospectively　interpreted　based　on　the　characterization　results　and　reported　references.　©　2014　The　Royal　Society　of　Chemistry.