Strongly enhanced photocurrent response for Na doped Ta3N5-nano porous structure
Highly ordered nanoporous (nanochannels) Ta 2O 5 layers were formed by electrochemical anodization of Ta in a glycerol-ethylene glycol mixture containing NH 4F and (NH 4) 2SO 4. The layers were then immersed in Na 2SO 4 and annealed in NH 3. This treatment leads to Na-doped Ta 3N 5 nanostructures that exhibit an apparent band gap of ~ 1.6 eV (compared to 2.1 eV for pure Ta 3N 5). The doped structure, moreover, shows an almost 10 times higher photoelectrochemical current response in the visible range than pure Ta 3N 5. This finding represents thus a novel pathway to drastically increase the photoresponse of Ta 3N 5 which can find wide ranging applications in photoelectrochemical devices. 2012 Elsevier B.V.