RESUMO
In recent years, metallic nanoparticle (NP)-two-dimensional material hybrids have been widely used for photocatalysis and photoreduction. Here, we introduce a femtosecond laser reduction approach that relies on the repetitive ablation of recast layers by usi-ng temporally shaped pulses to achieve the fast fabrication of metallic NP-two-dimensional material hybrids. We selectively deposited silver-reduced graphene oxide (Ag-rGO) hybrids on different substrates under various fabrication conditions. The deposition of the hybrids was attributed to the redistribution of the cooling ejected plume after multiple radiation pulses and the exchange of carriers with ejected plume ions containing activated species such as small carbon clusters and H2O. The proposed one-step in situ fabrication method is a competitive fabrication process that eliminates the additive separation process and exhibits morphological controllability. The Ag-rGO hybrids demonstrate considerable potential for chemomolecular and biomolecular detection because the surface-enhanced Raman scattering signal of the enhancement factor reached 4.04 × 108.
RESUMO
Titanium dioxide (TiO2) is one of the most promising candidates for photoelectrochemistry applications. For a high photoelectrochemistry performance, the control of crystal structure and crystal facet is essential. The phase transformation of TiO2 is conventionally achieved by thermal annealing. Here, we report an approach for selective phase transformation of TiO2 containing exposed reactive facets with improved photoelectrochemistry performance. After femtosecond laser processing, TiO2 nanotubes with exposed reactive anatase {010} facets are prepared, and they have a maximum photocurrent density more than 5 times that of pure anatase. Additionally, this strategy can induce phase transformation in a selective area, which shows the advantages of patterning processing. Our method constructs a promising strategy for preparing functional nanomaterials with high performances and functionality.