Preparation of ultrafine PrMnO_3, modification and photocatalytic

Title: Preparation of ultrafine PrMnO_3, modification and photocatalytic
　　Author: Zhang Kan
　　Degree awarded: Wuhan University of Technology
　　Keywords: PrMnO_3;; photocatalysis;; sol - gel;; fine;; doping
　　Summary:
　　Rare earth oxides, rare earth carbonates and transition metal nitrates as raw material, "sol - gel" method with "vacuum drying" technology, ultrafine perovskite PrMnO_3 and Ce, Nd, Co, Fe-doped PrMnO_3, with the TG-DTA, XRD, FT-IR, TEM and other means of characterization, study of preparation conditions on perovskite PrMnO_3 structure and morphology. Neodymium Magnets Methyl orange photocatalytic degradation reaction as a guideline to evaluate the reaction of the catalytic activity of ultrafine PrMnO_3. The results showed that:
　　(1) 170 ℃ Pr-Mn dry gel is mainly amorphous, complementary to each other into a small amount of crystalline PrO (OH), heat treatment process, 500 ℃ generated Pr6O11, 700 ℃ generated Mn_2O_3, Pr affect the crystallization of Mn , 900 ℃ when the crystallinity is better to be single phase perovskite PrMnO_3.
　　(2) 170 ℃ dry gel by the large number of good dispersion of small spherical particles, uniform particle size, ranging in diameter between 10-20nm; after heat treatment, grain growing up, and a certain reunion due to dehydration, 900 ℃ dry gel was spherical, particle size range between 50-100nm.
　　(3) Ce, Nd and Fe-doped perovskite PrMnO_3 caused by the A-site cation defects and improve the PrMnO_3 photocatalytic activity; Co http://www.everbeenmagnet.com/en/products/110-sintered-neodymium-magnets doping cations caused by defects in the same time, Co into the perovskite B sites, partial replacement of Mn, formed PrMn_ (1-x) Co_xO_ (3 λ) (x = 0.1,0.2,0.3,0.4), Co and Mn together constitute the conduction band, PrMnO_3 significantly improved the photocatalytic activity. Meanwhile, the spacing d value increases slightly with x decreases, perovskite PrMn_ (1-x) Co_xO_ (3 λ) reduced cell parameters, cell volume shrinkage.
　　(4) degradation of methyl orange photocatalytic reaction has a kinetic characteristics.
　　Degree Year: 2010