We have determined the Schottky barrier height (0.23 eV) and efficient photoelectron generation in novel multisegmented Au/TiO2 nanorod arrays.

The as-synthesized TiO nanorods a-TNR (amorphous TiO layer covering the crystalline anatase TiO core) and TNR (fully crystalline anatase TiO) were decorated with reduced graphene oxide (rGO) to synthesize two series of TiO + rGO composites with different nominal loadings of GO (from 4 to 20 wt%). The structural, surface and electronic properties of the obtained TiO + rGO composites were analyzed and correlated to their performance in the photocatalytic oxidation of aqueous bisphenol A solution. X-ray photoelectron spectroscopy (XPS) analyses revealed that charge separation in TiO + rGO composites is improved due to the perfect matching of TiO and rGO valence band maxima (VBM). Cyclic voltammetry (CV) experiments revealed that the peak-to-peak separations (ΔE) are the lowest and the oxidation current densities are the highest for composites with a nominal 10 wt% GO content, meaning that it is much easier for the charge carriers to percolate through the solid, resulting in improved charge migration. Due to the high charge carrier mobility in rGO and perfect VBM matching between TiO and rGO, the electron-hole recombination in composites was suppressed, resulting in more electrons and holes being able to participate in the photocatalytic reaction. rGO amounts above 10 wt% decreased the photocatalytic activity; thus, it is critical to optimize its amount in the TiO + rGO composites for achieving the highest photocatalytic activity. BPA degradation rates correlated completely with the results of the CV measurements, which directly evidenced improved charge separation and migration as the crucial parameters governing photocatalysis.

Despite the increasing number of successful treatments for cancer, new forms of therapy are urgently 12 required in order to combat the disease. In this investigation we have produced an innovative material based on 13 FePt/SiO 2 /Au hybrid nanoparticles that exhibit a combination of photothermal and magnetic properties as a basis 14 for a local hypothermia treatment. The magnetic cores of FePt exhibit the superparamagnetic properties necessary 15 for biomedical purposes, while the gold nano-shells absorb light in the near-infrared range, because of their semi-16 continuous nature and the nanoparticle clustering, as predicted by our modelling. The as-prepared hybrid 17FePt/SiO 2 /Au nanoparticles were irradiated with a low-energy laser (λ=808 nm) in a water suspension, which 18 resulted in a photo-thermal effect and a temperature increase of 10 °C during the 10 minutes of irradiation. 19Furthermore, the results of experiments performed on a suspension of hybrid nanoparticles in a flow of water 20 confirmed that they can be magnetically manipulated and retained at a targeted location under realistic dynamic 21 conditions. This dual magnetic and optical effect makes the FePt/SiO 2 /Au hybrid nanoparticles excellent 22 candidates for photothermal cancer treatments, with the added bonus of being able to magnetically extract the 23 particles after their use.

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