【摘要】 在600℃温度下热分解配位前驱体,制备出5种稀土铁酸盐颗粒(ReFeO₃,Re=Y³⁺、La³⁺、Sm³⁺、Gd³⁺和Ho³⁺)。采用XRD、SEM、Uv-Vis DRS以及VSM等手段对所制备产物进行物相、表面形貌、能带结构以及磁性能等进行表征。XRD表明,含Y³⁺、La³⁺和Gd³⁺的前驱体灼烧后产物为单相正交晶系的ReFeO₃,而Sm³⁺和Ho³⁺的前驱体灼烧后产物则是由ReFeO₃和微量的稀土氧化物Re₂O₃两相构成的复合物。DRS结果反映,所有灼烧产物从紫外区到可见区对光都有比较强的相应,能带结构有轻微差异。VSM结果显示,所有产物均具有一定的弱铁磁性,其中HoFeO₃的磁性最强,磁参数分别为:H_c=28 656 A/m,M_s=0.286 Am²/kg,M_r=0.076 Am²/kg。同时用MO作为光降解模型,研究产物的光催化活性。MO降解结果显示,所有产物对MO光降解都具有良好的催化性,其中YFeO₃展现更强的催化效果,MO在其作用下,光照4h的降解率达86%。更多还原

【Abstract】 Five rare earth ferrites of ReFeO₃(Re= Y³⁺, La³⁺, Sm³⁺, Gd³⁺ and Ho³⁺) are prepared through thermal decomposition coordination precursor at the temperature of 600 ℃ with diethylenetriaminepentaacetic acid（H₅dtpa） as ligand. The phase, morphology, band structure and magnetic property of samples prepared are characterized by XRD, SEM, Uv-Vis DRS and VSM. XRD results show that as-prepared products including Y³⁺, La³⁺and Gd³⁺, respectively, are only the phase of orthorhombic ReFeO₃, while the samples including Sm³⁺, Ho³⁺, respectively, are composed of principal ReFeO₃ and a trance amount of Re₂O₃. The band gap of E_g is about 2.0 eV for all products, exhibiting strong response to light from ultraviolet region to visible region. All products show weak magnetism, and HoFeO₃ exhibitsrelatively strong magnetism with H_c=28 656 A/m, M_s=0.286 Am²/kg and M_r=0.076 Am²/kg. Moreover, catalytic activity for all samples prepared is studied based on the degradation of MO resolution. From result of degradation rate of MO, it can be seen that all samples prepared exhibit good photcatalytic activity. Among them, YFeO₃ displays better photo-catalytic activity, and 86% of MO is degraded under light irrational time of 4 h in the present of it.更多还原