Surface Activation of Faceted Photocatalyst: When Metal Cocatalyst Determines the Nature of the Facets

Pt nanoparticles with tunable size are prepared on the entire surface of facet-engineered Cu₂WS₄ decahedral photocatalyst via a kinetic-controlled chemical reduction process. The {101} facets of the photocatalyst which featured photo-oxidation, are successfully activated for photoreduction by Pt. The resulting photocatalyst shows an activity nine times higher compared to that of the only {001}-facets activated catalyst obtained by a conventional in situ photodeposition route.