Synthesis, Chatacterization And Application Research Of Several Nanomaterials

Devoloping new method, expanding new system, fabricating new structureand exploring new applications are the leading edge of nanomaterials. In the pastyears, the preparation and application of CPs at micro/nanoscale have arousedincreasing interest. More and more CPs with various morphologies andstructures has been prepared by various methods. Recent work demonstrated thatCPs was suitable precursors for the production of nanoscale materials with optimizedmorphologies and properties. By finely controlling the conditions, metals, metaloxides, metal sulfides or other nanosized materials with different morphologies can beobtained from CPs precursor. In this thesis, RE-based coordination polymers (CPs)submicrospheres have been prepared from pyridine-2,5-dicarboxylic acid andRE(NO3)3via a facile microwave heating method, employing N,N-dimethylformamide (DMF) as solvent. After calcining in different astomspheres,rare earth oxide (RE2O3), rare earth nitride/C (REN/C) and cyano oxide (Ln2O2CN)submicrospheres were obtained. Furthermore, nanoscale metal oxide semiconductorwas synthesized by a remarkably simple and facile route via a synproportionationreaction at room temperature. The as-obtained products were characterized bydifferent measurement technologies. The as-prepared products were characterized byX-ray powder diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR),scanning electronic microscope (SEM), transmission electron microscopy (TEM), etal. The main content of this thesis is as following:(1) Preparation of rare earth coordination polymers (CPs)RE-based coordination polymers (CPs) submicrospheres have been prepared frompyridine-2,5-dicarboxylic acid and RE(NO3)3via a facile microwave heating methodin5min, employing N, N-dimethylformamide (DMF) as solvent. Thesubmicrospheres are with diameters of100-400nm.(2) Preparation of other materials by calcininig the rare earth coordinationpolymers under different conditionsSeveral CPs submicrospheres (RE=La, Gd and Y) were selected and calcined atdifferent atomospheres (including air, N2and NH3). After calcining in the air, rareearth oxide (RE2O3) submicrospheres were obtained. When calcined in the N2atmosphere, LaN/La2O3/C composite spheres were obtained for La-based CPs. ForGd(Y)-based CPs, Gd2O3(Y2O3)/C composite spheres were obtained. Interestingly,when conducted in NH3atmosphere, La-based CPs produces La2O2CN2submicrospheres, while the Gd-based and Y-based CPs submicrospheres giveGd2O3/GdN/C and Y2O3/C submicrospheres, respectively. As examples of theirpotential applications, their upconversion properties of the as-prepared products wereinvestigated. The as-prepared products show excellent properties. The signal of the sample calcining in air atmosphere was strongest, however signals of the samplescalcining in N2and NH3atmospheres were very weak. Although the signal of Gd-CPs:Yb3+, Er3+was stronger than the samples calcining in N2and NH3, it was muchweaker compared with the sample calcining in the air.(3) Synthesis and properties of Cu2O nanocrystals as an integrated photocatalyticadsorbent (IPCA)Obtained Cu2O NCs as an integrated photocatalytic adsorbent (IPCA) exhibit highadsorption affinity combined with superior photocatalytic activity for the removal ofvarious organic pollutants in wastewater. A remarkable maximum adsorption capacitytoward HA (405.5mg·g-1) was achieved on Cu2O NCs, and more than99.5%HAmolecules could be degraded within2h. Moreover, the Cu2O NCs also exhibit superdegradation efficiency for other organic pollutants (99%for CR,90%for MO, and75%TC, respectively). In addition, more than94%of natural organic matter (NOM)was eliminated by Cu2O NCs from a real wastewater.