Publication date: 22nd July 2026
Photoelectrochemical (PEC) water oxidation offers a promising route for solar fuel production, yet its efficiency remains critically limited by the sluggish kinetics of the anodic oxygen evolution reaction (OER) [1,2]. BiVO₄ is among the most studied photoanode materials due to its favorable bandgap and valence band position, but its practical performance is severely hindered by poor charge transport and surface recombination [3]. Here, we report a novel scalable fabrication strategy that, for the first time, combines the Autodrop process and automated spray coating for the sequential deposition of FePO₄ and Ti₃C₂Tₓ MXene overlayers onto BiVO₄ photoanodes. This two-step approach enables precise control over each functional layer while remaining fully compatible with large-scale production. The FePO₄ interlayer acts as a surface passivation and hole-transport layer [4], while the highly conductive MXene nanosheets serve as a co-catalytic interface and conductive bridge, collectively suppressing recombination and accelerating OER kinetics. Systematic optimization of MXene loading reveals a critical balance between MXene coverage and FePO₄ exposure, achieving an approximately 50% improvement in photocurrent density. Furthermore, the MXene overlayer enhances photoanode stability by facilitating continuous hole extraction and preventing BiVO₄ degradation under operating conditions. This work demonstrates a viable and reproducible route toward high-performance, stable photoanodes for solar fuel applications.
