The Preparation And Properties Of CeO₂/g-C₃N₄ Mixed Particles And Fe₂O₃/g-C₃N₄ Composites

Nowadays,polymeric graphitic carbon nitride(g-C3N4)is regarded as a novel two-dimensional material with narrow band gaps,which has drawn enormous attention.G-C3N4 is widely applied to prepare nano-composite materials because of its excellent properties,such as multiple defects,appealing electronic and environment friendly.Due pure g-C3N4 possesses the unique optical electronic structure and photoinduced electron-hole recombination efficiency,it has been investigated for its photoluminescence capacity.On the other hand,when combining g-C3N4 with metal oxide,the nano-composites possess excellent photocatalytic performance and decrease photoinduced electron-hole recombination efficiency.And it is attributed to g-C3N4 with large specific surface area and stable chemical properties.In addition,when combining metal oxide with g-C3N4,the magnetic property was also converted.The magnetically separable ability of nanocomposites was exhibited good recycle property efficiently after the photocatalytic reaction.In this paper,we try to prepare CeO2/g-C3N4 mixed particles and Fe2O3/g-C3N4 nanocomposites and carry out the following work to study properties of samples;first,the pure phase CeO2 and Fe2O3 are synthesized by simple two-step method.And then,the g-C3N4 is prepared by calcination method.At last,the nanocomposites samples were prepared by a simple physical mixing method.The main laboratories operations are as follows:The preparation of CeO2/g-C3N4 mixed particles and the enhanced photoluminescenceThe precursors of CeO2 were synthesized with Ce(NO3)3·6H2O and CO(NH2)2 as the source material and precipitator by the dispersant of PVP in different temperatures.Next the CeO2 was annealed by the precursor.And the g-C3N4 sample was prepared by directly heating urea at high temperature.Last,the CeO2/g-C3N4 mixed particles were synthesized by a physical mixing-calcinations method.We can measure the data during the experiment.The crystalline structure was studied by the X-ray diffractometer(XRD).The crystalline size and morphology of the particles were observed by scanning electron microscopy(SEM).The photoluminescence spectra difference of CeO2/g-C3N4 mixed particles and pure particles(CeO2/g-C3N4)were obtained with fluorescence spectrometer.Furthermore,the mixed particles under different temperature(CeO2/g-C3N4 @120 ? and CeO2/g-C3N4@ 140 ?)are compared carefully.Based on the above analysis,the different interaction of CeO2 and g-C3N4 in different temperature can cause different surface defects.Therefore,the recombination rate of photogenerated charges and the emission intensity are enhanced when combining CeO2 with g-C3N4 @120 ?,due to the fewer surface defects in the CeO2@120 ?.Magnetically separable Fe2O3/g-C3N4 nanocomposites with cocoon-like shape:magnetic properties and photocatalytic activitiesThe precursors of FeCl3·6H2O were synthesized with Ce(NO3)3·6H2O which mixed ethylene glycol and NaOH as the source material.The mixed solution was added into the Teflon-lined autoclaves for some time.Next the obtained precipitates were washed and dried to obtain the precursor of Fe2O3.And the precursors were transferred to the muffle furnace to obtain Fe2O3.On the other hand,the g-C3N4 powder was synthesized by heating urea.At last,g-C3N4 and Fe2O3 were mixed and dispersed in ultrasonication by a physical mixing-calcinations method to obtain Fe2O3/g-C3N4 composites.During the experiment,we measure the samples through the following methods.The crystalline structure of composites was studied by the X-ray diffractometer(XRD).The crystalline size and morphology of the samples were observed by scanning electron microscopy(SEM).The magnetic conversion of the samples was studied by a vibrating sample magnetometer(VSM).And the photocatalytic activity of the samples was investigated by degrading the Rhodamine B(RhB).Through the measurement methods above,Fe2O3 cocoon-like nanostructure is coated onto the porous structure of g-C3N4 from Scanning electron microscopy micrographs.The saturation magnetization(Ms)of the Fe2O3 nanoparticles decreases when combined with g-C3N4 particles from magnetization curves.The photocatalytic capability of Fe2O3/g-C3N4 nanocomposites is superior to that of pure g-C3N4 and Fe2O3.Furthermore,the magnetically separable ability of Fe2O3/g-C3N4 nanocomposites was exhibited efficiently by the external magnet to improve the use and circulation of catalyst.