Synthesis of S/Cr doped mesoporous TiO2 with high-active visible light degradation property via solid state reaction route

S/Cr doped mesoporous TiO₂ (S-TiO₂, Cr-TiO₂, S-Cr-TiO₂) were successfully synthesized via a simple, effective and environmental benign solid state reaction route. The low angle XRD patterns demonstrated that the resulting samples possess mesostructures. The further characterizations via N₂ adsorption-desorption and XPS showed that the typical S/Cr co-doped mesoporous TiO₂ (S-Cr-TiO₂(5S-5Cr)) possesses mesopore with the high specific surface area of 118.4 m²/g and narrow pore size distribution, and both S and Cr have been incorporated into the lattice of TiO₂ with the amounts of 4.16% sulfur and 7.88% chromium, respectively. And Raman spectroscopy shows that the surface of S-Cr-TiO₂ (5S-5Cr) material possesses stretching vibrational peaks at ∼709, ∼793 cm⁻¹ are assignable to the Ti-O-Cr, O-Cr (Ti)-OH bonds, respectively. Interestingly, the UV-vis displayed that the absorption regions of S/Cr doped mesoporous TiO₂ cover the visible light region. As for the series of S-Cr-TiO₂ samples, the absorption region even extends to near infrared region with strong adsorption. Moreover, compared with the pure titanium dioxide (P25-TiO₂), the photodegradation properties of bromocresol green (BCG) on the S/Cr doped mesoporous TiO₂ showed excellent photocatalytic properties under visible light irradiation. Within 50 min visible light irradiation, 82.6% of the initial BCG was degraded for the S-Cr-TiO₂ (6S-4Cr) photocatalyst.