Flower-like Bi₂O₂CO₃and BiOCl:Fast Synthesis And Photocatalytic Performance

In recent years, photocatalysis has aroused tremendous interest for its potential applications in the treatment of global energy and environmental problems using solar energy directly. Bismuth-containing photocatalysts have gradually become one of the most attractive novel photocatalysts due to their unique electronic structure, excellent visible-light absorption ability and high catalytic activities. In this thesis, flower-like Bi2O2CO3and BiOCl were fast synthesized at room temperature, and the effects of preparation conditions on the photocatalytic performances of the samples were investigated. The as-prepared samples were characterized by XRD, SEM, TEM and UV-vis DRS techniques et al. The photocatalytic activity of the as-prepared samples was evaluated by the degradation of dyes under Xe lamp irradition. In addition, the relationship between the structure and photocatalytic performances of catalysts was discussed.A facile, fast and low-cost method was developed for the synthesis of novel flower-like Bi2O2CO3in an aqueous medium with the assistance of cetyltrimethylammonium bromide (CTAB). It was found that CTAB was indispensable for the fabrication of flower-like Bi2O2CO3. The as-obtained flower-like Bi2O2CO3showed high photocatalytic activity and photostability in the degradation of Rh-B, MO, crystal violet and their mixture under Xe lamp irradiation. What’s more, the relationship between the structure and the catalytic performance was investigated and it was deduced that the high photocatalytic activity is mainly attributed to the flower-like morphology, thin nanoplates and large specific surface area.Novel BiOCl nano-flowers with narrow band gap (2.87eV) was conveniently synthesized at room temperature in the presence of L-lysine. The optimal condition for the generation of BiOCl nano-flowers with good photocatalytic performance includes HNO3=2mL(65wt%), L-lysine concentration=4g/L and calcination at400℃for3h. It was found that L-lysine, HNO3and calcination were indispensable for the fabrication of flower-like BiOCl with (110) plane exposed. To summarize, the roles of HNO3was to get pure phased BiOCl and to control the size of BiOCl by controlling the hydrolysis of BiCl3. The addition of L-lysine was to facilitate the formation of nano-flowers. The calcination treatment was essential to dislodge the template and achieve a surface of (110) orientation. The BiOCl nano-flowers showed excellent photocatalytic activity in the degradation of Rh-B dye under visible light (λ≥435nm), Rh-B could be decomposed completely after50min. We deduced that (110) plane and nano-flowers structure played an important role in high activity of the catalyst.