Structural, thermal, and optical properties of gold nanoparticle-doped bismuth borate glasses: effect of concentration

In the present work, a host network of bismuth borate glass with composition (30-x)Bi₂O₃-70B₂O₃-xHAuCl₄⋅3H₂O where x = 0, 0.01, 0.1, and 1 mol% was prepared through a conventional melt-quench technique. The influence of gold nanoparticles on the structural, thermal, and optical properties of these bismuth borate glasses was investigated by preparing and comparing a series of glass samples containing varying concentrations of gold ranging from 0 to 1 mol%. No post-treatment was applied to ensure a fair comparison of previously reported results. X-ray diffraction analysis confirmed the amorphous nature of the glasses, with noticeable changes in peak broadening indicating varying degrees of disorderness with gold incorporation. Fourier Transform Infrared spectroscopy revealed modifications in structural groups and bonding due to gold doping. High-resolution Transmission Electron Microscopy and Selected Area Electron Diffraction confirmed the formation of gold nanoparticles within the glass matrix. Thermal analysis demonstrated altered glass stability with varying gold concentrations making them potent applicants for fiber drawing. UV–Vis absorption spectra exhibited reduced transparency with increasing gold content, along with the appearance of a localized surface plasmon resonance peak at 580, 600, and 605 nm for 0.01-, 0.1-, and 1-mol% gold, respectively. These results confirm the successful incorporation of gold nanoparticles and their significant impact on the optical properties, particularly in tailoring the plasmonic behavior of the glasses, offering potential for photonic applications.