Preparation of FeS2 nanotube arrays based on layer-by-layer assembly and their photoelectrochemical properties

Well-aligned one-dimensional iron pyrite FeS2 nanotube arrays have been fabricated via layer-by-layer assembly technique on ZnO nanorod arrays in combination with subsequent sulfurization. The as prepared products were confirmed to be pure phase pyrite FeS2 with Fe/S ratio approaching 1/2. Typical nanotube structure was observed for the FeS2 with average outer diameter of 150 +/- 20 nm and wall thickness of 50 +/- 5 nm. Comparisons of photoelectrochemical properties between FeS2 nanotubes and FeS2 nanoparticles were conducted. Tafel polarization curves and electrochemical impedance spectroscopy indicate that FeS2 nanotubes possess high corrosion resistance and electrochemical stability. The J-V curves show that the photocurrent at 1.0V for FeS2 nanotubes is more than five times larger than that of FeS2 nanoparticles, indicating enhanced photoresponse and rapid charge transfer performances of 1-D nanotube structure. The enhanced photoelectrochemical properties mainly benefit from the unique architecture features of nanotube array structure. (C) 2015 Elsevier B.V. All rights reserved.