Ta3N5 nanotube arrays for visible light water photoelectrolysis

Nano Lett. 2010 Mar 10;10(3):948-52. doi: 10.1021/nl903886e.

Abstract

Tantalum nitride (Ta3N5) has a band gap of approximately 2.07 eV, suitable for collecting more than 45% of the incident solar spectrum energy. We describe a simple method for scale fabrication of highly oriented Ta3N5 nanotube array films, by anodization of tantalum foil to achieve vertically oriented tantalum oxide nanotube arrays followed by a 700 degrees C ammonia anneal for sample crystallization and nitridation. The thin walled amorphous nanotube array structure enables transformation from tantalum oxide to Ta3N5 to occur at relatively low temperatures, while high-temperature annealing related structural aggregation that commonly occurs in particle films is avoided. In 1 M KOH solution, under AM 1.5 illumination with 0.5 V dc bias typical sample (nanotube length approximately 240 nm, wall thickness approximately 7 nm) visible light incident photon conversion efficiencies (IPCE) as high as 5.3% were obtained. The enhanced visible light activity in combination with the ordered one-dimensional nanoarchitecture makes Ta3N5 nanotube arrays films a promising candidate for visible light water photoelectrolysis.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Electrolysis / instrumentation*
  • Equipment Design
  • Equipment Failure Analysis
  • Light
  • Nitrogen / chemistry*
  • Nitrogen / radiation effects
  • Photochemistry / instrumentation*
  • Tantalum / chemistry*
  • Tantalum / radiation effects
  • Transducers*
  • Water / chemistry*

Substances

  • Water
  • Tantalum
  • Nitrogen