Tantalum nitride nanotube photoanodes: establishing a beneficial back-contact by lift-off and transfer to titanium nitride layer

TL;DR

This study demonstrates that using TiN/Ti2N layers as back contacts for Ta3N5 nanotube photoanodes significantly improves their photoelectrochemical performance by lowering the onset potential and increasing photocurrent, due to enhanced conductivity.

Contribution

The paper introduces a novel TiN/Ti2N back contact method for Ta3N5 nanotubes, improving electron transport and photoelectrochemical efficiency.

Findings

Lowered onset potential for photocurrents (~0.5 V RHE)

Increased photocurrent magnitude

Enhanced electron transport due to TiN/Ti2N back contact

Abstract

In this work we introduce the use of TiN/Ti2 N layers as a back contact for lifted-off membranes of anodic Ta3N5 nanotube layers. In photoelectrochemical H2 generation experiments under simulated AM 1.5G light, shift of the onset potential for anodic photocurrents to lower potentials is observed, as well as a higher magnitude of the photocurrents compared to conventional Ta3N5 nanotubes (~ 0.5 V RHE ). We ascribe this beneficial effect to the improved conductive properties of the TiNx -based back contact layer that enables a facilitated electron-transport for tantalum-nitride based materials to the conductive substrate.