Ni-Epoxy/Ni Multifunctional Layer Integrated Perovskite-Based Photoanode with High Electric Field

In this study, we present a transparent perovskite-based photoanode consisting of a CsPbBr3-based photogenerated electric field layer and a Ni-Epoxy/Ni layer with integrated multifunctions of light transmission, sealing, charge conducting, and catalyzing. The Ni-Epoxy/Ni layer successfully constructed longitudinal charge transport channels and provided an interface with active sites, while achieving an average visible transmittance of more than 70%. For photoelectrochemical (PEC) water oxidation at 1.23 VRHE in 0.5 M KOH solution, the maximum photocurrent densities of the photoanode were 17.28 and 5.19 mA cm–2 when light was excited from the FTO and the multifunctional layer side, respectively, based on an actual working area of 2 cm2. The photoanode exhibited a 1450 mV shift of onset potential compared with the multifunctional layer. Due to the existence of a high built-in electric field, bias-free complete PEC water splitting was realized, and the peak photocurrent density was 0.46 mA cm–2. The multifunctional layer’s water resistance increased the photoanode’s working time from less than 1 min to more than 30 min.