The present study proposed a novel approach to fabricate multi-tiered nanoporous TiO2-TiN composite (NTTC) films on Ti foils by facile anodization in an aqueous electrolyte containing NH4NO3. The NTTC films possess a unique laminated nanostructure with a tier thickness of 250-600 nm, where each tier comprises cylindrical pores of phi 30-60-nm diameters. The NTTC films contained 2.2-6.0 at.% nitrogen in the forms of TiN and adsorbed NH4+ ions, which is attributed to the electrochemical/chemical reactions during anodization in NH4NO3 electrolytes. Moreover, novel dual-hierarchical NTTC films with large (phi 250-300 nm) and small (phi 80 nm) pores on the top and bottom layers, respectively, are fabricated by a successive anodization in sulfate- and nitrate-based electrolyte systems. Specifically, the dual-hierarchical NTTC film formed in (NH4)(2)SO4 double right arrow NH4NO3 solutions delivers a high-specific capacity of around 2504 mAh cm (3), and exhibit excellent cycling stability with nearly 100% capacity retention during lithium-ion battery tests. The high capacities of the NTTC films can be attributed primarily to the inclusion of highly conductive TiN in the TiO2 matrix (improving the anodic TiO2 film conductivity) and their highly nanoporous structure (facilitating Li+ insertion/de-insertion because of the high surface area and presence of fast ion diffusion paths.) (C) 2016 Elsevier Ltd. All rights reserved.