Abstract
In order to improve the photocatalytic degradation efficiency of nano-TiO(2), reduce its usage and realize recycling and reuse, CaCO(3)-TiO(2) composite photocatalyst was prepared with calcium carbonate (CaCO(3)) and TiO(2) in a grinding machine through the integration of grinding depolymerization, dispersion and particle composition. The photocatalytic degradation performance, recycling performance, structure and morphology of CaCO(3)-TiO(2) were studied. The interaction mechanism between CaCO(3) and TiO(2) and the improvement mechanism for the photocatalytic performance of TiO(2) were also discussed. The results show that under the UV light irradiation for 20 and 40 min, the degradation efficiency of methyl orange by the composite photocatalyst with 40% TiO(2) (mass fraction) was 90% and 100%, respectively. This was similar to that of pure TiO(2), and the performance of the composite photocatalyst was almost unchanged after five cycles. CaCO(3)-TiO(2) is formed by the uniform loading of nano-TiO(2) particles on the CaCO(3) surface, and the nano-TiO(2) particles are well dispersed. Due to the facts that the dispersion of nano-TiO(2) is improved in the presence of CaCO(3) and the charge transport capability is improved through the interfacial chemical bonds between CaCO(3) and TiO(2), the formation of this complex is an intrinsic mechanism to improve the photocatalytic efficiency of nano-TiO(2) and reduce its usage in application processes.