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

TL;DR

This study demonstrates that tungsten doping in Ta3N5 nanotubes reduces the band gap and significantly improves photoelectrochemical water splitting efficiency, offering a promising approach for solar fuel generation.

Contribution

It introduces a novel tungsten doping method for Ta3N5 nanotubes that narrows the band gap and enhances PEC water splitting performance.

Findings

W doping decreases band gap from 2 eV to 1.75 eV.

W-doped Ta3N5 nanotubes with co-catalysts show ~33% higher photocurrents.

Tungsten doping improves PEC water splitting efficiency.

Abstract

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.