WO3/TiO2 heterostructures tailored by the oriented attachment mechanism: insights from their photocatalytic properties

Abstract

Efficient WO₃/TiO₂ photocatalysts were obtained through the Oriented attachment mechanism via hydrothermal annealing, which entailed using previously prepared WO₃ particles and commercial TiO₂ nanoparticles as “building blocks”. The photoreactivity of this material towards organic contaminant degradation was enhanced compared to commercial TiO₂ because the coupling of the WO₃/TiO₂ structures reduced the recombination of the photogenerated charges in anatase TiO₂. The pristine WO₃ nanoparticles were prepared by hydrothermally assisted degradation of a W-peroxocomplex and all of the prepared materials were characterized by X-ray diffraction, Raman spectroscopy, thermogravimetric analysis, electron microscopy, Near-Infrared spectroscopy, nitrogen physical adsorption (BET method), photoluminescence spectroscopy (PL) and diffuse reflectance spectra (DRS). The optimal compositional ratio for the WO₃/TiO₂ heterostructures was 30–40 wt% of WO₃. We also provided the interface formation in the HRTEM images by observing the presence of the lattice spacing of the (101) and (120) planes of TiO₂ anatase and WO₃ orthorhombic crystals, respectively, which allows the charge migration during the photocatalyzed degradation of the heterostructures, thereby improving their photoactivity.