Nanosheets Self-install In-situ Doped N (BiO) ₂ CO ₃ Grade Microspheres Controlled Synthesis And Catalytic RhB And NO Visible Performance

Humanity was faced with the significant environmental problems of water and air pollution. Inorder to make full use of solar energy to solve environment pollution problem development ofvisible light photocatalyst response range, in this paper, In situ N-doped （BiO）₂CO₃hierarchicalmicrospheres with superior visible light catalyticactivity were fabricated by a one-pot hydrothermalmethod using dicyandiamide and bismuth citrate as raw materials. The as-prepared samples werecharacterized by XRD, SEM, FT-IR, UV-vis DRS and PL. The results indicated that the ratio ofaddition dicyandiamide, the temperature of and the time of hydrothermal reaction have significantimpact on morphological structure, band gap and electronic-hole recombination rate of theas-prepared （BiO）₂CO₃.（BiO）₂CO₃hierarchical microspheres with the biggest Specific surfacearea,the narrowest band gap and the lowest electronic-hole recombination rate of the as-prepared（BiO）₂CO₃was obtained by24hours-hydrothermal reaction under180℃and making the rawmaterials that the molar ratio of addition dicyandiamide is1. The optimal parameters of preparation（BiO）₂CO₃hierarchical microspheres in industry have been obtianed. The growth mechanism of（BiO）₂CO₃was discussed as the analysis of phase structure of solid product from each reactionstage, composition, and morphology. During the hydrothermal process of dicyandiamide, ammoniahas been produced and dissolved in aqueous solution ionized OH-.Only in the presence of OH-,bismuth citrate could hydrolyzed as BiO+and citric acid root, as further hydrolysis CO₂-3has beenproduced. The important intermediate of （BiO）4（OH）2CO3has turn up in generating （BiO）₂CO₃,meanwhile, N atoms were in situ doped into the （BiO）₂CO₃lattice. N doping made the lightresponse spectra of （BiO）₂CO₃extend into visible light region significantly. The band gapnarrowing of （BiO）₂CO₃due to N doping was evidenced by valence band XPS. Then we found thatnano self-assembly （BiO）₂CO₃hierarchical microspheres through Ostwald ripening. It involveamporphous particles were produced through reaction, nucleation, crystallization and aggregationprocesses. With the extension of reaction time, stacked uniform solid microspheres with smallparticles attached on edges were generated by the consumption of particles. The particle size of（BiO）₂CO₃hierarchical microspheres uniformly with stable character were generated throughOstwald ripening. The in situ N-doped （BiO）₂CO₃hierarchical microspheres structure showedexcellent visible light photocatalytic activity toward aqueous Rh B and gas-phase NO degradation,which was higher than N-doped TiO₂and C-doped TiO₂although them with higher specific surfacearea. After repeated recycling, the in situ N-doped （BiO）₂CO₃hierarchical microspheres in thephotocatalytic performance is stable. The research results of this paper would offer train of thoughtof Bi system catalyst morphology controllable synthesis, modification and the application ofenvironment purification. Provides technical basis for the application of Bi system catalyst.