This paper reports a facile fabrication method for robust and separated polycrystalline Ta4N5 nanocolumn arrays on a FTO/glass substrate that involves using reactive sputtering, which provides an alternative approach to fabricating nitrides without using caustic NH3 gases. The bandgap of Ta4N5 nanocolumns made at 600 degrees C was observed to be approximately 2.5 eV. The excellent photodegradation performance was demonstrated in an environment with a pH of 10, in which approximately 80% of methylene blue (5 ppm) was photodegraded in 90 min. The incident photon-to-current efficiency of the 600 degrees C sample showed equivalent or superior characteristics compared with the Ta3N5 and IrO2/Ta3N5 thin films reported in the literature. The photoelectrochemical current measurement also demonstrated the stability of the sample. These features suggest that Ta4N5 nanocolumns are promising in the field of photocatalysis. (C) The Author(s) 2015. Published by ECS. All rights reserved.