Photocatalytic reduction and oxidation activities of nanosheet-assembled anatase TiO2 microspheres

Nanosheet-assembled anatase titanium dioxide (TiO₂) microspheres (ST) have been successfully synthesised using the hydrothermal method. The physical and chemical properties of ST were well characterised by X-ray diffraction, X-ray photoelectron spectroscopy, field emission scanning electron microscopy, transmission electron microscopy, photoluminescence and Brunauer-Emmett-Teller (BET) analysis. The photocatalytic reduction and oxidation activities of the as-prepared sample were evaluated by removing heavy metal Cr (VI) and by degradation of organic dyes (methyl orange (MO) and rhodamine B (Rh B)), respectively. P25 and commercial pure anatase TiO₂ were used for comparison. The nanosheet-assembled anatase TiO₂ microspheres displayed better photocatalytic efficiency towards the photo-reductive conversion of Cr (VI). Moreover, it also exhibited higher photocatalytic activity for the degradation of organic dyes compared with that of P25 and commercial pure anatase TiO₂.