The primary objective in researching the anode side of electrochemical CO₂ reduction reaction (CO₂RR) is to substitute the frequently employed Ir anodic catalyst with more readily available and cost-effective non-noble metal oxide. When organic molecules are loaded on the Cu₂O surface, a synergistic effect can be formed between different components. This effect can accelerate electron transfer, provide new active sites, and further enhance the performance of reactants of oxygen evolutionreaction (OER). This study proposes a new type of anodic catalyst, PDI/Cu₂O/Cu, and investigates its OER activity and three other anodic catalysts (IrO₂/Ti mesh, Ni foam, and Pt mesh) in the CO₂RR system. The results show that PDI/Cu₂O/Cu exhibited OER activity with an overpotential of 422.1 mV to drive a current density of 70 mA·cm⁻² in neutral electrolytes. Compared to IrO₂/Ti mesh, the overpotential of perylene tetracarboxylic di-(propyl imidazole) (PDI)/Cu₂O/Cu is decreased by 490 mV. This significantly lowers the energy consumption of the CO₂RR system without compromising the performance of CO₂RR. Furthermore, the use of precious metal materials is unnecessary, leading to a substantial reduction in the cost of the anodic catalyst. PDI/Cu₂O/Cu holds the potential to serve as a non-precious metal alternative to Ir in neutral electrolytes as an anodic catalyst.

Photoelectrochemical syngas production using photoanode-driven systems from aqueous CO₂ is a promising technology. To address the challenge of poor selectivity caused by the wide band gap of photoelectrode, we introduce a novel photoanode, PDI/Cu₂O/Cu, where PDI is the perylene tetracarboxylic di-(propyl imidazole). Using Cu₂O as a substrate enhances charge transfer kinetics, while PDI modification mitigates photocorrosion and augments photoelectrochemical CO₂ reduction reaction (PEC CO₂RR) activity. This enhancement stems from PDI’s narrow band gap and efficient visible light absorption. The syngas production achieved a noteworthy 124.47 μmol/(cm²·h) at 1.57 V vs. RHE, making it an optimal feedstock gas for hydrocarbon synthesis. Detailed UV–vis spectra indicate that layered structure significantly improves the absorption edge of the photoanode, facilitating enhanced utilization of visible light. Additionally, the electron lifetime of the PDI/Cu₂O/Cu photoanode is substantially increased which is also one of the factors affecting the reactivity, as demonstrated by the Bode phase plot.