The　direct　decomposition　of　CO2　to　produce　CO　and　O-2　requires　extremely　high　temperatures　in　catalysis.　Here,　we　proposed　the　photoassisted　oxygen　vacancy　active　sites　for　CO2　dissociation　to　lower　the　reaction　temperature.　The　designed　low-crystalline　Nb2O5　nanoribbons　(LC-Nb2O5　NRs)　showed　a　good　CO　production　rate　under　mild　conditions　(＜=　250　degrees　C)　with　Xe　lamp　irradiation.　Under　light　irradiation,　the　rate　of　CO　yields　of　LC-Nb2O5　NRs　increased　to　68　mu　mol　g(-1)　h(-1)　at　250　degrees　C,　with　no　activity　at　all　under　light　conditions.　The　high　activity　arose　from　unsaturated　coordination　with　low　crystallinity　and　CO2　reactants　as　an　electron　donor　for　forming　an　electron　cycle　with　the　Nb2O5　NRs,　which　played　a　key　role　in　the　generation　of　oxygen　vacancies　for　the　subsequent　photoexcited　electron　transfer　process　at　mild　temperatures.　The　feasibility　of　this　approach　is　further　verified　over　Nb2O5/C　nanofibers　that　make　full　use　of　photothermal　and　photoelectric　effects　to　achieve　long-term　stable　CO2　decomposition.