Crystallization And Particle Regulation Of Yttrium-Cerium Interdoped Carbonates And Their Applications In Electrochemical Sensing And Polishing

Although the crystallization technology of yttrium carbonate and cerium carbonate has achieved large-scale industrial applications,it is still a great challenge to obtain the precursor products with desired application functions through the regulation of crystallization process.In this study,yttrium and cerium were selected as the representatives of heavy rare earth and light rare earth,and the influence law of their mutual doping on the crystallization process and the particle characteristics of their products was studied.Their oxides were obtained by calcination and used as electrochemical sensing and polishing materials,and their application performance and the correlation with particle characteristics were evaluated.In order to solve the problem that yttrium carbonate crystallize slowly when ammonium bicarbonate is used to precipitate yttrium at room temperature,the crystallization speed is improved by doping cerium.The crystal formation and the evolution of particle morphology and size characteristics are observed by SEM and XRD analysis techniques.The results show that under the temperature condition of30℃,the nucleation and crystallization of yttrium carbonate can be significantly promoted by doping proper amount of cerium ion in the low molar ratio of NH₄HCO₃:YCl₃of 2,and cerium doped yttrium oxide（CYO）were obtained by calcining the synthesized fuzzy spherical large particles of yttrium hydrocarbonate precursor.An electrochemical sensor based on CYO/CNT/GCE was constructed by using the modified electrode.It was found that the electrochemical sensor CYO/CNT/GCE using CYO doped with cerium ion of 1 mol%has the best electrocatalytic effect on paracetamol.The differential pulse voltammetry has a wide linear range(0.2μmol?L^-1-6.0 mmol?L^-1),high sensitivity[16.5μA·(μmol·L^-1)^-1·cm^-2],and low detection limit(0.07μmol?L^-1)for the determination of paracetamol.It was applied to the detection of acetaminophen,and the recovery rate was 97.7%-104.0%.In order to solve the problem that cerium carbonate crystallized too quickly at room temperature,this paper synthesized cerium carbonate at 60℃and doped yttrium ions to inhibit its crystallization,and synthesized the precursor of small particle morphology of crystal free cerium carbonate.When the molar ratio of NH₄HCO₃:Ce Cl₃is between 4-6 and the doping amount of yttrium ion is greater than 3 mol%,the small particles of Ce₂（CO₃）₃·8H₂O can still be obtained.IR,XPS,TG,XRD and Raman analysis of the precursor and its calcined oxide show that the doping is effective.The yttrium-doped cerium oxide（YCO）particles obtained by calcination inherit the morphology of carbonate precursor,and can be used to prepare good suspension slurry by ultrasonic dispersion for polishing K9 glass.Based on Zeta potential,p H,material removal rate and other parameters in the polishing process,the best preparation conditions are determined as follows:The material removal rate reached 173.4 nm/min and the surface roughness decreased to 0.67 nm when the doping amount of yttrium ion was 5 mol%,the molar ratio of NH₄HCO₃:Ce Cl₃was 6,the aging period was 0 h,the calcination was 800℃and the ultrasonic dispersion was1 h.