The Synthesis And Catalytic Properties Of Bismuth-based Catalysts

With the development of photocatalysis technology,it is important to exploit visible light activated photocatalysts with high photocatalytic activities.Bismuth-based semiconductors contain p-block Bi³⁺ ions with a formal ns2np0 electronic configuration that is responsible for its stereochemically activity.Moreover,most of bismuth-based semiconductors possess unique layered structure.In this thesis,based on a comprehensive review of the publications and current issues of bismuth-based semiconductors,we take the representative narrow-band-gap Bi₂O₃ and wide-band-gap BiOCl semiconductors as the research objects,study the relationship between surface co-catalysts and bulk semiconductor materials,the characteristic of interface charge transfer,and explore their applications in other fields.The main results can be summarized as follows:（1）Enhanced photocatalytic activity of Bi₂O₃ under visible light irradiation by Cu（Ⅱ）clusters modification.Pure α-Bi₂O₃ samples with rod-like structure were synthesized by a facile hydrothermal method,and amorphous Cu（Ⅱ）clusters were deposited on the as-obtained α-Bi₂O₃ samples by an impregnation method.Gaseous 2-propanol（IPA）was chosen as a probe to evaluate the photocatalytic activities of the samples.It was found that the photocatalytic activity of Bi₂O₃ was significantly improved after grafted Cu（Ⅱ）clusters.（2）Porous Bi₂O₃ nanospheres were prepared by solvothermal method.The as-obtained 8-Bi₂O₃ porous nanospheres were first employed in the catalytic reduction of nitrobenzenes into anilines.The 8-Bi₂O₃ nanospheres can be converted into semi-metallic rhombohedral bismuth inheriting the morphological properties in the presence of NaBH4.Furthermore,the reduction reaction of nitrobenzenes into anilines can be highly achieved over the in-situ formed bismuth porous nanospheres.（3）The uniform BiOCl nanoplates were obtained by one-step hydrothermal method.Rhodamine B（RhB）degradation was used as a probe reaction to in-depth understanding the dye sensitization process over the as-synthesized BiOCl sample.As a result,it was found that BiOCl nanoplates possess high performance for the RhB degradation under visible light irradiation than TiO₂ did.Based on the experiments,the reasons were that there exists a strong interaction between RhB and BiOCl nanoplates,which greatly improves the electron conductivity for interfacial electron injection.Moreover,benefiting from the proper conduction band edge potential of BiOCl nanoplates,the injected electrons can be trapped by the surface absorbed O2 to generate reactive oxygen species,resulting in the high photosensitization activity for the RhB degradation under visible light illumination.（4）Hierarchical BiOCl microflowes were synthesized by one-step solvothermal method.The amorphous Fe（Ⅲ）clusters were grafted on the as-obtained BiOCl microflowers through a simple impregnation method.Gaseous acetaldehyde was chosen as a probe to calculate the photocatalytic activities of the samples.Amazingly,the photocatalytic activity for the decomposition gaseous acetaldehyde can be enhanced by deposited of Fe（Ⅲ）clusters under visible light irradiation to a large Extent.