Anisotropically Epitaxial P-N Heterostructures Actuating Efficient Z-Scheme Photocatalytic Water Splitting

Crafting anisotropically epitaxial p-n heterostructures with Z-scheme charge transmission is a promising avenue toward excellent photocatalytic efficiency, yet the large lattice mismatch and diverse crystal growth habits between components have often arisen as a big challenge to this goal. Here, anisotropically epitaxial p-n heterostructures with 19.8% lattice mismatch are obtained via a dynamics-mediated seeded growth tactic under reaction temperature as low as 60 °C. Structural analyses reveal the epitaxy of hexagonal CuS nanoplates onto CdS nanowires through forming misfit dislocations at {101̄0} interface and stacking faults inside CuS nanoplates. Experimental and density functional theory calculation results verify the Z-scheme photo-carriers transfer in epitaxial CdS-CuS heterostructures, which exhibit a much enhanced visible-light-driven H₂ generation capability than non-epitaxial CdS/CuS counterpart, and the site-specified NiOOH photo-deposition over CdS-CuS heterostructures leads to a distinguished H₂-evolving activity ≈65 and 36 times promotion compared to those of pristine CdS and Pt-loaded (3 wt.%) CdS, respectively. The study can enlighten new thinking to the steerable synthesis of epitaxial nanostructures with large lattice mismatch for various promising applications.