In this paper, we have developed a synchronous etching-epitaxial growth approach for the fabrication of facet-coupling NaTaO3/Ta2O5 heterostructured nanofibers, where the NaTaO3 nanocubes in-situ grow epitaxially along [1 2 1] on the crystal plane (1 1 0) of electrospun Ta2O5 nanofibers. In this protocol, elaborately adjusting the etching reaction kinetics of Ta2O5 can effectively regulate the heterogeneous nucleation and crystal growth rate of NaTaO3, leading to form facet-coupling heterojunctions. Owing to facet-coupling heterojunction characters, the as-obtained NaTaO3/Ta2O5 heterostructures show an improved light absorption and charge separation because of their reduced interfacial defects and the minimum charge transfer resistance. As a result, they even in the absence of any cocatalysts can exhibit a photocatalytic activity for hydrogen production as high as 1579 mu mol h(-1) g(-1), far more than that of the corresponding Ta2O5, NaTaO3 or the conventional heterostructured counterparts. The synchronous etching-epitaxial growth strategy developed here can be extended to the fabrication of other well-defined heterojunctions, especially of those whose precursors have a rapid hydrolysis rate. The as-obtained well-defined heterojunctions are promising for the effective utilization of solar energy by improving the separation and transfer efficiency of photogenerated charges. (C) 2015 Elsevier B.V. All rights reserved.