Preparation And Application Of Cuprous Oxide/Conjugated Polymer Composite Materials

Cuprous oxide nanoparticles were prepared by ion exchange method with copper nitrate trihydrate,sodium hydroxide and ascorbic acid as the main raw materials.The Cu₂O nanoparticles were characterized by X-ray diffraction（XRD）,transmission electron microscopy（TEM）,UV-vis diffuse reflection spectroscopy（DRS）and photoluminescence spectroscopy（PL）.The results show that Cu₂O exhibits cubic crystal.The as-obtained Cu₂O nanoparticles were agglomerated seriously when the mole ratio of Cu（NO₃）₂ and NaOH is 0.67:1,while Cu₂O was single cubic when the mole ratio of Cu（NO₃）₂ and NaOH is 0.33:1.The photocatalytic activities of Cu₂O nanoparticles were evaluated by degradation of phenol aqueous solution.The effects of different preparation conditions on the visible light photocatalytic activity of Cu₂O nanoparticles were investigated.The results show that the optimum preparation condition is found that the molar ratio of Cu（NO₃）₂ and NaOH is 0.33:1,the mole ratio of Cu（NO₃）₂ and Vc is 1:0.5,the concentration of NaOH solution is 7.43 g/L and the dropping time of Cu（NO₃）₂ is 30 min.The cuprous oxide/polyacrylonitrile（Cu₂O/PAN）composites were fabricated by solvent changing,in-situ ion exchange and reduction reaction with polyacrylonitrile（PAN）,copper nitrate Cu（NO₃）₂,sodium hydroxide and ascorbic acid as the main raw materials.Then the nanocomposites of cuprous oxide and cyclized polyacrylonitrile with conjugate structure（Cu₂O/CPAN）were prepared by calcining Cu₂O/PAN under nitrogen atmosphere.The Cu₂O/CPAN nanocomposites were characterized by SEM,TEM,XRD,FTIR,XPS,DRS,and PL.The results show that Cu₂O nanoparticles are uniformly distributed in Cu₂O/CPAN composites,and the mean size of Cu₂O in the composites is smaller than that of pure Cu₂O.The conjugated structures of C=N and C=C formed after the heat-treatment of PAN under nitrogen atmosphere.At the same time,the small amount of Cu₂O was reduced in situ to generate copper by dehydrogenation products of PAN.The modification of CPAN obviously increases the absorbance of visible light,and increases the separation efficiency of photogenerated electron-hole pairs.The experimental results show that the photocatalytic degradation of phenol photocatalyzed by Cu₂O/CPAN composites under visible light is in accord with the first order reaction kinetics.The modification of CPAN significantly improves the photocatalytic activity of Cu₂O.The optimum preparation condition is found that the mass ratio of PAN and Cu₂O is 1:5,the heat treatment temperature is 250℃,the heat treatment time is 1.0 h.After seven cycles,the Cu₂O/CPAN composites still possesses high photocatalytic activity.