In this work, we report a novel synthesis of nanoscale anatase TiO2 with dominant highly active {1 1 1} facets by a simple one-step hydrothermal route with the assistance of NH4F and HF. In this progress, the exposed crystal facets of TiO2 can been directly tuned by controlling the mole ratio of NH4+ and F-. When the mole ratio of NH4+ and F- reach 1:2, nanoscale anatase TiO2 with dominant {1 1 1} facets can be obtained. Nanoscale anatase TiO2 with exposed {1 0 1} or {0 0 1} facets will be prepared when there is only ammonia or HF added respectively. Such nano-TiO2 with exposed highly active {1 1 1} facets has large specific surface area and shows excellent photocatalytic activity: as much as 2-3 times than that of TiO2 nanosheets with exposed {0 0 1} facets and commercial Degussa P25 which confirms the {1 1 1} facets have higher photocatalytic activity than {0 0 1} and {1 0 1} facets. The higher photocatalytic activity of {1 1 1} facets can be ascribed to the fact that all Ti and O atoms on the surface are unsaturated Ti-5c,Ti-3c and O-2c modes which produces a higher adsorption and degradation ability. The present work demonstrates a explore of hydrothermal synthetic method for controlling preparation of nano-materials. (C) 2014 Elsevier B.V. All rights reserved.