Nanometer Lafeo <sub> 3 </ Sub> Controlled Synthesis And Tio <sub> 2 </ Sub> Bridged Composite Photocatalyst Construct

Global range of environmental pollution and energy crisis have drawn increasingly serious people's extensive concern, nano-semiconductor photocatalytic technology due to its high efficiency, degradation thoroughly, non-toxic and no secondary pollution etc, becomes the hot research areas. And among them, developing visible light photocatalist is the key factor which realization of semiconductor catalyst actualization. In view of the research status, perovskite oxide is an ideal catalyst of visible light semiconductor materials which has narrow-band gap. But there is a bottleneck factor during the preparation process which limited the further improved of the photocatalytic activity. Based on the above discussion, to solve the assemble inssue, we used KH550 as a inhibitor to synthesis nano-sized LaFeO₃ by citrate sol-hydrothermal method to decrease the particle size and increase the surface area, so that the visible light photocatalytic activity of LaFeO₃ can be promoted. Further, we used KH550 as the bridge agent to synthesis the compound of LaFeO₃ and TiO₂, in order to improve the poor photocatalytic activity of LaFeO₃, and at the same time, we also solve the problem of lacking effective recombination between LaFeO₃ and TiO₂.Nano-sized LaFeO₃ with large surface area has been synthesized by a silane coupling agent (3-Triethoxysilylpropylamine) modified citrate sol-hydrothermal method using KH550 as inhibitor. The results show that the preparing LaFeO₃ has small particle size and large surface area, and the larger is the KH550 content, the smaller is the particle size. A possible synthetic mechanism related to the KH550 is the formed SiO₂ can retard the nano-crystal to contact directly and aggregate at high temperature, and further control the growth of resulting crystallites. The photocatalytic activity evaluation show that the modified LaFeO₃ exhibit high visible photocatalytic activity, this is attributed to the small particle size. The compound LaFeO₃-bridge-TiO₂ was prepared by a simple method used KH550 as the bridge agent. The results show that the suitable content of KH550 can be used as the bridge anent to link LaFeO₃ and TiO₂, consequently to realize efficient compound, which greatly improved the separative efficiency of photo induced carrier. The photocatalytic activity evaluation shows that the compound of LaFeO₃-bridge-TiO₂ shows higher visible light photocatalytic activity than the compound prepared by the traditional method.