Facile assembly of tetragonal Pt clusters on graphene oxide for enhanced nonlinear optical properties

• Tetragonal Pt clusters on the surface of graphene oxide using anatase TiO2 as a template is proposed.
• OL effect of Pt-cluster/GO hybrid is superior to that of CNTs, a benchmark optical limiter.
• OL behavior of the metal/GO hybrid can be tailored by altering the aggregation means of metal NPs.
• OL effect of the Pt-cluster/GO hybrid is owed to the RSA in the GO sheet and NLS in the metal NPs.

A facile method to assemble tetragonal Pt clusters on the surface of graphene oxide (Pt-cluster/GO) using anatase TiO2 as a template is proposed. The morphology and structure of Pt-cluster/GO were investigated, revealing that tetragonal Pt clusters with a diameter of 20–50 nm composed of 2–3 nm Pt nanoparticles (NPs) were homogenously decorated on the surface of GO. The nonlinear optical properties were characterized by the open-aperture Z-scan technique in the nanosecond regime using a laser with wavelength of 532 nm. The as-prepared Pt-cluster/GO hybrid was found to show strong optical limiting (OL) effects for nanosecond laser pulses at 532 nm, and the OL performance is superior to that of carbon nanotubes, a benchmark optical limiter. Furthermore, the Z-scan results showed that the OL performance of the Pt-cluster/GO hybrid is superior to that of GO and the Pt-NP/GO hybrid. The OL behavior of the metal/GO composite nanostructure can be effectively tailored by altering the aggregation means of metal NPs. Scattering measurements suggested that nonlinear scattering (NLS) played an important role in the observed OL behavior in the Pt-cluster/GO hybrid. The OL properties of the Pt-cluster/GO hybrid are attributed to the reverse saturable absorption in the GO sheet and NLS in the metal NPs.