Stable and Efficient CuO Based Photocathode through Oxygen-Rich Composition and Au-Pd Nanostructure Incorporation for Solar-Hydrogen Production

Enhancing stability against photocorrosion and improving photocurrent response are the main challenges toward the development of cupric oxide (CuO) based photocathodes for solar-driven hydrogen production. In this paper, stable and efficient CuO-photocathodes have been developed using in situ materials engineering and through gold palladium (Au-Pd) nanoparticles deposition on the CuO surface. The CuO photocathode exhibits a photocurrent generation of similar to 3 mA/cm(2) at 0 V v/s RHE. Time-of-flight secondary ion mass spectrometry (TOF-SIMS) analysis and X-ray spectroscopy (XPS) confirm the formation of oxygen-rich (O-rich) CuO film which demonstrates a highly stable photocathode with retained photocurrent of similar to 90% for 20 min. The influence of chemical composition on the photocathode performance and stability has been discussed in detail. In addition, O-rich CuO photocathodes deposited with Au-Pd nanostructures have shown enhanced photoelectrochemical performance. Linear scan voltammetry characteristic shows similar to 25% enhancement in photocurrent after Au-Pd deposition and reaches similar to 4 mA/cm(2) at 0 V v/s RHE. Hydrogen evolution rate significantly depends on the elemental composition of CuO and metal nanostructure. The present work has demonstrated a stable photocathode with high photocurrent for visible-light-driven water splitting and hydrogen production.