arXiv subjects

Sabina Grigorescu

Publications and source records attributed to Sabina Grigorescu.

2 recordsLinked to original sources

arXiv2016

Open top anodic Ta3N5 nanotubes for higher solar water splitting efficiency

In the present work we grow self-organized Ta2O5 nanotube layers in a H2SO4/NH4F electrolyte at various elevated temperatures. Under optimized conditions we obtain 4 μm long nanotubes that are well adherent to the substrate and can be grown very homogenous over large surface areas. Moreover, the key advantage of this approach is that an open top morphology (initiation layer free) is obtained. After a suitable conversion treatment in NH3 atmosphere Ta3N5 nanotubes are obtained, that after (Co-Pi+Co(OH)x) modification provide, under AM 1.5G illumination conditions, a photoelectrochemical current response of 4.7 mA cm-2 at 1.23 V vs RHE.

cond-mat.mtrl-sci↗

arXiv2016

Tungsten doping of Ta3N5-Nanotubes for Band Gap Narrowing and Enhanced Photoelectrochemical Water Splitting Efficiency

Ordered W-doped Ta2O5 nanotube arrays were grown by self-organizing electrochemical anodization of TaW alloys with different tungsten concentrations and by a suitable high temperature ammonia treatment, fully converted to W:Ta3N5 tubular structures. A main effect found is that W doping can decrease the band gap from 2 eV (bare Ta3N5) down to 1.75 eV. Ta3N5 nanotubes grown on 0.5 at% W alloy and modified with (CoOH)x as co-catalyst show ~33% higher photocurrents in photoelectrochemical (PEC) water splitting than pure Ta3N5.

cond-mat.mtrl-sci↗