Bismuth oxyiodide/titanium dioxide (BiOI/TiO2) heterostructured nanofibers with exposed (110) BiOI facets were synthesized by electrospinning and hydrothermal methods. The BiOI/TiO2 heterostructures with exposed (110) BiOI facets exhibited an enhanced photoreactivity, for which the methylene blue and phenol degradation rate is increased by more than two times and the photocurrent density is 12 times as high as that of BiOI with exposed (110) facets. EPR spectroscopy indicated that the hydroxyl radicals and superoxide radicals could be generated by BiOI/TiO2 heterostructures with exposed (110) BiOI facets. Based on the experimental results, the enhancement of the photocatalytic activity could be attributed to the strong oxidization by hydroxyl radicals, enlarged band gap, lowered valence band position, and suppressed recombination of photoinduced electron-hole pairs by the manipulation of heterostructures with exposed (110) BiOI reactive facets.