Metal-Supported TiO₂/SiO₂ Core-Shell Nanosphere Photocatalyst for Efficient Sunlight-Driven Methanol Degradation

The development of novel and active photocatalysts to industrialize photocatalysis technology is still a challenging task. In this work, a novel method is presented to prepare TiO2/SiO2 NSs by covering SiO2 nanospheres (NSs) with titanate-nanodiscs (TNDs) followed by calcination. In this regard, SiO2 NSs are first synthesized and then TNDs are deposited on the SiO2 NSs using a layer-by-layer deposition technique. The morphology of the prepared samples is analyzed via SEM and TEM analyses before and after the deposition. The analysis of metal (Cu, Pt, and Ni) loading on calcined TNDs/SiO2 NSs reveals the highest specific surface area (109 m(2)/g), absorption wavelength extension (up to 420 nm), and photocatalytic activity for the Cu-loaded sample. In addition, studying the effect of metal content shows that loading 3% Cu leads to the highest photocatalytic activity. Finally, it is demonstrated that H2S treatment can improve the photocatalytic activity by around 15%. These findings suggest the calcined TNDs/SiO2 NSs are a versatile photocatalyst with potential applications in other processes such as hydrogen production and CO2 valorization.