Enhanced photocalytic activity of hollow anatase microspheres by Sn4+ incorporation

Anatase-phase hollow microspherical Ti1-xSnxO2 solid solutions are one-pot fabricated by a fluoride-mediated self-transformation strategy. The resulting samples are characterized by scanning electron microscopy, transmission electron microscopy, powder X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy, nitrogen sorption, and UV-visible diffuse reflectance spectroscopy. It is discovered that the morphology and porous structures do not exhibit remarkable change until adding a higher concentration of Sn4+ into the synthetic system. The Still incorporation obviously inhibits the crystallization of anatase nanocrystals but promotes the phase transformation from anatase to rutile phase. Generally, the Sn4+ incorporation induces decreased anatase crystallite sizes, increased specific surface areas, and the blue shift of adsorption edges. The moderately doped Ti1-xSnxO2 solid solutions exhibit better photocatalytic activity for the decomposition of acetone in air and rhodamine B in aqueous solution, which is, correlated with the effect of Sn4+ on the physicochemical properties in terms of electronic structures and textural characteristics.