Study On Synthesis And Photocatalytic Properties Of Acid Activated Calcined Kaolinite Supported Cu, Ni Doped TiO₂

Titanium dioxide(Ti O2), as a photocatalyst, has received a great deal of attention as its chemical stability, non-toxicity, low cost, and other advantageous properties, however, due to its defective, such as easy to lose and difficult to recover and separate, wide band gap(3.2 e V), titania is difficult to be applied to the treatment of organic wastewater. To overcome these limitations and increase its utilization ratio in the field of wastewater treatment, numerous efforts have been made to improve the photocatalytic activity through doping and modifying the surface property of Ti O2, etc.In this study, X-Ti O2/SO42-/CK(X=Cu、Ni)composite photocatalysts were successfully obtained via in-situ method using raw materials, including tetrabutyl titanate, cupric nitrate, nickel nitrate and kaolinite. The photocatalytic activities of the prepared composite photocatalysts were evaluated via a probe reaction to degrade Rhodamine B under visible light and study the focuses on the influence of doping amount, H2SO4 concentration for immersion and calcination temperature on the photocatalytic activity. Experimental results indicated that the prepared catalyst presented high visible light photocatalytic activity while the highest photocatalytic activity reached on the X-Ti O2/SO42-/CK(X=Cu、Ni)composite with 1wt% of Cu addition and 0.75at% of Ni addition, 20% sulfuric acid concentration for carrier and 450°C calcined temperature.The properties of the result composites were characterized by XRD, BET, EDS, TEM, FTIR, UV-vis and XPS. The results of XRD showed that characteristic peak of anatase Ti O2 and rutile Ti O2 exist at the same time; the BET analysis results showed that the surface area of the catalyst increased after fixing; HTEM and EDS recognized that the particles distributed on the surface of the carrier were Cu and Ti O2, and the lattice spacing of Ti O2 has been changed; XPS analysis revealed that the binding energy of Ti and O reduced, probably due to the change of the lattice spacing of Ti O2 which the dopant leads; Py-FTIR showed that the prepared catalysts contained B and L acid sites.