Uniform ALD deposition of Pt nanoparticles within 1D anodic TiO2 nanotubes for photocatalytic H2 generation

In the present work we investigate the utilization of Pt nanoparticles produced by atomic layer deposition (ALD) within anodic TiO2 nanotube (NT) layers for photocatalytic H2 production. By varying the number of ALD cycles, Pt nanoparticles with different diameters were produced, uniformly decorating the tube walls. The Pt nanoparticle size (2-15 nm), the Pt mass loading and areal density were strongly dependent on the number of Pt ALD cycles. The deposited Pt nanoparticles turned out to be highly effective as a co-catalyst for photocatalytic H2 generation. The most effective performance for solar light photocatalysis was reached after 26 ALD cycles (yielding an optimal area coverage with particles of diameter ≈ 7 nm). For UV light, the optimum photocatalytic efficiency was reached after 40 ALD cycles.