This work for the first time reports engineered oxygen-deficient, blue TiO₂ nanocrystals with co-exposed {101}-{001} facets (TiO_2-x{001}-{101}) to enhance CO₂ photoreduction under visible light. The TiO_2-x{001}-{101} material demonstrated a relatively high quantum yield (0.31% under UV-vis and 0.134% under visible light) for CO₂ reduction to CO by water vapor and more than four times higher visible light activity compared with TiO₂ with a single {001} plane or {101} plane and TiO₂(P25). Possible reasons are the exposure of more active sites (e.g., under-coordinated Ti atoms and oxygen vacancies), the facilitated electron transfer between {001} and {101} planes, and the formation of a new energy state (Ti³⁺) within TiO₂ band gap to extend visible light response. In situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) study was applied to understand the roles of co-exposed {001}-{101} facets and Ti³⁺ sites in activating surface intermediates. The in situ DRIFTS analysis suggested that the co-exposed {001}-{101} facets increased the capacity of reversible CO₂ adsorption and that the combination of {001}-{101} and Ti³⁺ enhanced the activation and conversion kinetics of adsorbed species. The visible light responsive TiO_2-x{001}-{101} material is not oxidized after long time exposure  to an air environment.