Atomic Layer Deposition of TiO2 Nanocoatings on ZnO Nanowires for Improved Photocatalytic Stability

Abstract EN

Photocatalytic water splitting represents an emerging technology well positioned to satisfy the growing need for low-energy, low CO2, economically viable hydrogen gas production.

As such, stable, high-surface-area electrodes are increasingly being investigated as electrodes for the photochemical conversion of solar energy into hydrogen fuel.

We present a titanium dioxide (TiO2)/zinc oxide (ZnO) nanowire array using a hybrid hydrothermal/atomic layer deposition (ALD) for use as a solar-powered photoelectrochemical device.

The nanowire array consists of single crystalline, wurtzite ZnO nanowires with a 40 nm ALD TiO2 coating.

By using a TiO2 nanocoating on the high surface area-ZnO array, three advancements have been accomplished in this work: (1) high aspect ratio nanowires with TiO2 for water splitting (over 8 μm), (2) improved stability over bare ZnO nanowires during photocatalysis, and (3) excellent onset voltage.

As such, this process opens up new class of the micro/nanofabrication process for making efficient photocatalytic gas harvesting systems.