Efficient Photoelectrochemical Reduction of CO2 in Seawater with Cheap and Abundant Cu2O/Al2O3/TiO2 Electrode

The photoelectrochemical (PEC) reduction of carbon dioxide to environmentally friendly fuels is a promising strategy to address the challenge of clean energy demand. Semiconductor photocathodes such as Cu₂O enable the reduction of carbon dioxide, but their main drawback is their instability and susceptibility to photocorrosion. In this work, Al₂O₃ and TiO₂ were utilized to enhance stability, photoelectrochemical activity, and charge transport facilitation, resulting in a 2.8-fold increase in generated photocurrent density (1.4 mA/cm² at -0.2 V vs. RHE). The experiments were conducted in a 0.5 M NaCl solution, simulating seawater conditions, to evaluate the performance and stability of the system in an environment closer to real-world applications.