Diatom biosilica modified with Ce-Tb mixed oxide twinning nanoparticles and with polyphases quasi-crystalline Tb oxide nanoparticles

In this study, we developed a novel composite material by combining natural diatom biosilica with Ce-Tb mixed oxide and polyphase quasi-crystalline Tb oxide nanoparticles. Diatom biosilica, characterised by its highly ordered three-dimensional structure and excellent thermal, mechanical, and optical properties, serves as an ideal matrix for the synthesis of advanced functional materials. The composites were extensively characterised using techniques such as SEM, TEM, TGA, EDS, XRD, FTIR, and PL spectroscopy. The results indicate significant UV absorption (250–400 nm), strong visible photoluminescence (300–500 nm), and notable anti-Stokes emission (∼420 nm) under 800 nm excitation. Additionally, the composites exhibit remarkable thermal stability and hydrophobicity, making them promising candidates for applications in optoelectronic devices, photovoltaic systems, and high-resolution display technologies. • The synthesis of a new (Ce,Tb)O 2 /DBioSiO 2 and Tb x O y /DBioSiO 2 composites. • The phenomenon of twinning of mixed Ce-Tb oxide nanoparticles. • The polyphase composition of terbium oxide nanoparticles. • The new composites with anti-Stokes photoluminescence. • The hydrophobicity/non-wetting effect.