Improving the stability of electrodeposited Cu2O/β-Ni(OH)2 photoelectrodes for efficient solar water splitting

As sustainable hydrogen production becomes essential for transitioning to clean energy, enhancing the efficiency and stability of photoelectrodes for solar water splitting remains a critical challenge. This study addresses this need by developing Cu₂O-based photoelectrodes with improved endurance and performance. Cu₂O electrodes were electrodeposited on Au/Cr/glass substrates, optimized at pH 12, heat-treated at 200 °C, and protected with a 30 nm β-Ni(OH)₂ layer. Structural and electrochemical stability was assessed through X-ray photoelectron spectroscopy, scanning electron microscopy, and electrochemical impedance spectroscopy , revealing enhanced performance. The optimized electrodes demonstrated a photocurrent of approximately −0.7 mA/cm² at −0.4 V SCE , underscoring the potential of Cu₂O-based photoelectrodes for practical applications in renewable energy technologies . • Cu 2 O electrodes with improved chemical and structural stability and with photocurrent performance. • Influence of the electrodeposition pH and heat treatment on the Cu 2 O stability. • Use of a β-Ni(OH)₂ layer to protect the Cu 2 O photoelectrode without hindering the charge transfer for water splitting.