Leveraging the Synergistic Effects of Au/PANI/CuO Heterostructure for Enhanced Photoelectrochemical Water Splitting

Abstract This study explores a novel photoelectrode made from a combination of copper oxide (CuO), polyaniline (PANI), and gold nanoparticles (Au NPs) for efficient hydrogen production in photoelectrochemical (PEC) water splitting. The Au/PANI/CuO photoelectrode is fabricated using cost-effective methods, ensuring practical applications. The research evaluates the photoelectrode's morphology, structure, efficiency, and stability to optimize its performance in PEC reactions. Integrating Au, PANI, and CuO nanomaterials improves charge transfer, reduces resistivity, and minimizes charge recombination, resulting in significantly enhanced hydrogen production efficiency. Scanning electron microscopy (SEM) reveals that the CuO film has a rough texture with non-uniform particles, while the PANI/CuO film exhibits agglomerates and interconnected PANI nanofibers. The Au NPs are evenly distributed across the PANI/CuO film, with diameters ranging from 5 to 60 nm. Energy dispersive X-ray (EDX) analysis approves the presence of each element in the desired proportions, validating the successful fabrication of the Au/PANI/CuO photoelectrode. The Au/PANI/CuO photoelectrode exhibits enhanced light absorption properties due to the surface plasmon resonance (SPR) effect of Au NPs and the interaction between PANI and CuO. The Au/PANI/CuO photoelectrode demonstrates a remarkable 300-fold increase in photocurrent density (Jph) compared to pure CuO, achieving a maximum of 15 mA/cm² at -0.39 V vs. RHE. Additionally, the Au/PANI/CuO photoelectrode maintains a constant photocurrent density for 0.5 hours, showing superior stability compared to CuO, which experiences rapid decay. It also achieves a high IPCE value of 45% at nearly 500 nm, indicating efficient light utilization. Overall, this study presents a promising approach for designing efficient and stable photoelectrodes in PEC water splitting and hydrogen generation applications.