The spillover of hydrogen species and its role in tuning the activity and selectivity in catalytic hydrogenation have been investigated in situ using surface‐enhanced Raman spectroscopy (SERS) with 10 nm spatial resolution through the precise fabrication of Au/TiO2/Pt sandwich nanostructures. In situ SERS study reveals that hydrogen species can efficiently spillover at Pt‐TiO2‐Au interfaces, and the ultimate spillover distance on TiO2 is about 50 nm. Combining kinetic isotope experiments and density functional theory calculations, it is found that the hydrogen spillover proceeds via the water‐assisted cleavage and formation of surface hydrogen–oxygen bond. More importantly, the selectivity in the hydrogenation of the nitro or isocyanide group is manipulated by controlling the hydrogen spillover. This work provides molecular insights to deepen the understanding of hydrogen activation and boosts the design of active and selective catalysts for hydrogenation.

Plasmonic metals under photoexcitation can generate energetic hot electrons to directly induce chemical reactions.H owever,t he capability and fundamental insights of the transportation of these hot electrons at plasmonic metal-2D material interfaces remain unclear.H erein, hot-electron transfer at Au-graphene interfaces has been in situ studied using surface-enhanced Raman spectroscopy( SERS) with atomic layer accuracy.C ombining in situ SERS studies with density functional theory calculations,i ti sp roved that hot electrons can be injected from plasmonic Au nanoparticles to graphene and directly penetrate graphene to trigger photocatalytic reactions.W ith increasing graphene layers,t he transportation of hot electrons decays rapidly and would be completely blocked after five layers of graphene.M oreover, the transfer of hot electrons can be modulated by applying an external electric field, and the hot-electron transfer efficiency under electrochemical conditions is improved by over three times in the presence of amonolayer of graphene.

The spillover of hydrogen species and its role in tuning the activity and selectivity in catalytic hydrogenation have been investigated in situ using surface‐enhanced Raman spectroscopy (SERS) with 10 nm spatial resolution through the precise fabrication of Au/TiO2/Pt sandwich nanostructures. In situ SERS study reveals that hydrogen species can efficiently spillover at Pt‐TiO2‐Au interfaces, and the ultimate spillover distance on TiO2 is about 50 nm. Combining kinetic isotope experiments and density functional theory calculations, it is found that the hydrogen spillover proceeds via the water‐assisted cleavage and formation of surface hydrogen–oxygen bond. More importantly, the selectivity in the hydrogenation of the nitro or isocyanide group is manipulated by controlling the hydrogen spillover. This work provides molecular insights to deepen the understanding of hydrogen activation and boosts the design of active and selective catalysts for hydrogenation.

Broadband long-wavelength infrared (LWIR) optical absorbers have important applications in thermal emission and imaging, infrared camouflaging, and waste heat and biothermal energy utilization. However, the practical application of broadband LWIR optical absorbers requires low-cost and facile fabrication of large-area structures with limited thickness. This paper reports the design and fabrication of an ultrathin, broadband, omnidirectional, and polarization-independent LWIR optical absorber composed of anodized aluminum oxide and highly doped Si using the gradient refractive index strategy. The average absorption of the broadband optical absorber is higher than 95% in the 8–15 μm wavelength range, and it has wide incident angle and polarization tolerances. More than 95% of the optical energy in the wavelength range from 8 to 13 μm was absorbed within a depth of 8 μm, making this absorber the thinnest broadband LWIR dielectric absorber so far. The absorption remained above 90% after annealing at 800 °C in air. The infrared camouflage of the proposed absorber was successfully demonstrated with a human body background. With the advantages of facile fabrication, low-cost materials, restricted absorption thickness, and excellent thermal stability, the developed broadband LWIR optical absorber is very promising for the practical applications mentioned above.

Plasmonic metals under photoexcitation can generate energetic hot electrons to directly induce chemical reactions.H owever,t he capability and fundamental insights of the transportation of these hot electrons at plasmonic metal-2D material interfaces remain unclear.H erein, hot-electron transfer at Au-graphene interfaces has been in situ studied using surface-enhanced Raman spectroscopy( SERS) with atomic layer accuracy.C ombining in situ SERS studies with density functional theory calculations,i ti sp roved that hot electrons can be injected from plasmonic Au nanoparticles to graphene and directly penetrate graphene to trigger photocatalytic reactions.W ith increasing graphene layers,t he transportation of hot electrons decays rapidly and would be completely blocked after five layers of graphene.M oreover, the transfer of hot electrons can be modulated by applying an external electric field, and the hot-electron transfer efficiency under electrochemical conditions is improved by over three times in the presence of amonolayer of graphene.