title: Coordination polymer submicrospheres: fast microwave synthesis and their conversion under different atmospheres.
abstract: Rare earth (RE) based coordination polymer (CP) submicrospheres have been prepared from pyridine-2,5-dicarboxylic acid and RE(NO3)3 via a facile microwave heating method in 5 min, with N,N-dimethylformamide (DMF) as solvent. The submicrospheres have diameters of 100-400 nm. Furthermore, the surface of the microspheres is smooth and the microspheres are solid. Several CP submicrospheres (RE = La, Gd, Y) were selected and calcined under different atmospheres (including air, N2, and NH3). After calcination in air at 550 °C for 4 h, rare earth oxide (RE2O3) submicrospheres were obtained. On calcination under an N2 atmosphere, LaN/La2O3/C composite spheres were obtained for La-based CPs. For Gd(Y)-based CPs, Gd2O3(Y2O3)/C composite spheres were obtained. Porous carbon submicrospheres were obtained after the removal of RE2O3 and REN from the composite spheres. Interestingly, under an NH3 atmosphere, La2O2CN2 submicrospheres were produced from the La-based CPs. In addition, the Gd-based and Y-based CPs submicrospheres gave Gd2O3/GdN/C and Y2O3/C submicrospheres, respectively. As examples of their potential applications, their upconversion properties and electrochemical properties of the as-prepared products were investigated. This facile microwave synthesis method may offer an attractive approach for the preparation of other RE-CP micro-/nanostructures, and many interesting materials may be derived.
authors.affiliation: College of Chemistry and Chemical Engineering, Jiangxi Normal University , Nanchang 330022, People's Republic of China.
authors.forename: Shengliang
authors.initials: S
authors.lastname: Zhong
authors.forename: Hongyu
authors.initials: H
authors.lastname: Jing
authors.forename: Yuan
authors.initials: Y
authors.lastname: Li
authors.forename: Shungao
authors.initials: S
authors.lastname: Yin
authors.forename: Chenghui
authors.initials: C
authors.lastname: Zeng
authors.forename: Lei
authors.initials: L
authors.lastname: Wang