Water Chemical Treatment by Photocatalytic Activity of Graphene Oxide–Decorated Titanium Dioxide/Ag Nanocomposite

In the present study, gold nanoparticles (NPs) were fabricated by pulsed laser ablation (PLA) method in distilled water environment under different external electric field strengths. The effect of the electric field on the characteristics of produced NPs was traced through X-ray diffraction (XRD), Fourier transforms infrared (FT-IR) and transmission electron microscopy (TEM). Optical properties were studied by UV-visible spectroscopy. The XRD results showed an orthorhombic lattice, alongside the typical cubic structure of Au, which was attributed to the hydrogen incorporation in the crystalline structure of Au nanoparticles. The interaction between hydrogen and gold did not vary linearly with the increased of applied electric field. At an electric field of 20 V/cm, this interaction was almost negligible. Furthermore, the peak observed at around 2000 cm−1 in the FT-IR spectrum provided additional evidence for possible Au-H interactions. Based on the TEM images, some non-spherical shapes such as nanorods were successfully synthesized under higher electric field strengths. Moreover, the interaction between hydrogen and gold likely induced a slight blue shift in the UV-Vis spectrum. The formation of Au hydride makes our sample a promising candidate for use as an optical hydrogen sensor; however, further research is needed.