In　this　study,　we　first　developed　a　simple　synthetic　route　to　prepare　layered　structure　NH4Nb3O8　nanobelts,　and　then　converted　NH4Nb3O8　phase　to　single-crystal　Nb2O5　by　thermal　treatment　in　air.　The　lengths　of　the　nanobelts　range　from　several　hundreds　of　nanometers　to　several　tens　of　micrometers,　and　the　thickness　and　width　of　nanobelts　are　similar　to　15　and　similar　to　60　nm,　respectively.　Based　on　the　experimental　results,　a　possible　mechanism　for　the　formation　of　nanobelts　was　proposed.　Such　a　simple　synthetic　route　offers　great　opportunities　for　the　scale-up　preparation　of　one-dimensional　nanostructured　materials.　Furthermore,　the　synthesized　Nb2O5　nanobelts　were　successfully　employed,　for　the　first　time,　as　an　electrode　material　in　dye-sensitized　solar　cells　using　a　metal-free　idoline　dye　as　a　sensitizer　and　its　photovoltaic　performance　of　the　solar　cells　was　investigated　under　illumination　of　simulated　AM　1.5　solar　light　(100　mW　cm(-2)).　(C)　2008　Acta　Materialia　Inc.　Published　by　Elsevier　Ltd.　All　rights　reserved.