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−SiO2NPs, 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−SiO2NPs 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 β‐dihydronicotinamide adenine dinucleotide (NADH), thereby resulting in efficient photocatalytic H2 evolution.