Nanofabrication of a Solid-State, Mesoporous Nanoparticle Composite for Efficient Photocatalytic Hydrogen Generation.

Room-temperature self-assembly was used to fabricate a periodic array of uniformly sized Al3+ -doped SiO2 nanoparticles (Al-SiO2 NPs, 20-30 nm). The uniform mesoporous structure was suitable for uniformly incorporating and distributing Pt nanoparticles (PtNPs), which were used as hydrogen-evolution catalysts in artificial photosynthetic systems, without agglomeration during the catalytic reaction. When the surfaces of the Al-SiO2 NPs were covered with an organic photocatalyst (2-phenyl-4-(1-naphthyl)quinolinium ion, QuPh+ -NA), each PtNP was surrounded by multiple QuPh+ -NA ions. The structure allowed the PtNP to receive multiple electrons from QuPh. -NA molecules, which were generated by reduction of the photoexcited state of QuPh+ -NA ions (QuPh. -NA. + ) with ß-dihydronicotinamide adenine dinucleotide (NADH), thereby resulting in efficient photocatalytic H2 evolution.