PREPARATION AND PROPERTIES OF A NANO-TiO2 COMPOSITE PHOTOCATALYST SUPPORTED BY NATURAL QUARTZ

Abstract

The goal of this paper is to improve the technical level of preparing composite photocatalysts with SiO2-supported nano-TiO2, expand the selection range of SiO2 carriers, reduce expenses and understand the influence of SiO2 crystallization behavior. Natural quartz (Q/SiO2) powder was used as a carrier to prepare a Q/SiO2-TiO2 composite photocatalyst by hydrolyzing a butyl titanate solution and performing high-temperature calcination of the hydrolysate. The performance, morphology, structure and mechanism were tested and characterized. In addition, the as-prepared photocatalyst was compared with other amorphous SiO2 carrier composite photocatalysts. The results showed that the Q/SiO2 surface of Q/SiO2-TiO2 contained a uniform load of TiO2 with a 26.98% proportion. Anatase-type TiO2 was mainly present, and the size was 5–10[Formula: see text]nm. Moreover, Q/SiO2 and TiO2 were firmly combined in the form of Si–O–Ti bonds between the interfaces. The degradation rate of Q/SiO2-TiO2 to methyl orange solution was 99.59% under UV irradiation for 60[Formula: see text]min, which was equivalent to that of pure nano-TiO2. The degradation performance remained stable after four cycles. Compared with other amorphous SiO2 carriers, Q/SiO2 exhibited a higher load of TiO2. Furthermore, Q/SiO2 played a more significant role in inhibiting the phase transition of TiO2 to rutile and improving the photocatalytic performance.