Gd_(2)O_(3) nanoparticles modified g-C_(3)N_(4) with enhanced photocatalysis activity for degradation of organic pollutants

Gd_(2) O_(3) nanoparticles modified g-C_(3) N_(4) photocatalytic composites were synthesized by a simple one-step hydrothermal method.The structure,morphology,optical properties of the prepared photocatalyst were characterized by X-ray diffraction(XRD),field emission scanning electron microscopy(FESEM),field emission transmission electron microscopy(FETEM) and X-ray photoelectron spectroscopy(XPS).The result demonstrates that gadolinium is mainly dispersed on the surface of g-C_(3) N_(4) in the form of Gd_(2) O_(3),and does not destroy the lattice structure of g-C_(3) N_(4).Besides,the gadolinium can cause the red shift of the absorption edge of light,narrow the band gap,and increase the separation efficiency of the photogenerated electron and hole of g-C_(3) N_(4).Especially,the specific surface area of g-C_(3) N_(4) can be significantly increased.Furthermore,g-C_(3) N_(4)/Gd-0.05 displays the highest photodegradation performance when it is used for degradation of methyl orange(MO),methylene blue(MB) and Rhodamine B(RhB).The photodegradation rate of g-C_(3) N_(4)/Gd-0.05 composites is 72.4% for MO,95.5% for RhB,100% for MB after120 min under visible light(λ> 420 nm) irradiation.Narrow band gap promotes the separation of photogenerated electron and hole,which enhances the photocatalytic activity of g-C_(3) N_(4).It is noted that g-C_(3) N_(4)/Gd-0.05 exhibits excellent photocatalytic stability by the photocurrent and the cyclic photodegradation of MO.

The Influence of Annealing Temperature on the Structure and Properties of TiO_2 Films Prepared by Sputtering

The TiO2 fihus were prepared on slides by dc reactive magnetron spattering, then the samples were annealed at 300 ℃ ,350 ℃ ,400 ℃ ,450 ℃ ,500 ℃ and 550 ℃ , respectively. X-ray diffraction （XRD） was used to obtain the TiO2 film crystalline structure; X-ray photoelectron spectroscopy （ XPS ） was used to study the film surface stoichiometries ; surface morphologies were studied by scanning electron microscopy （SEM） ; the coatact angle was tested to indicate the TiO2 film wettability ; and the photocatalytic activity testing was couducted to evaluate the photocatalysis properties. The photocatalytic activity and contact angle testing results were correlated with the crystallinity , surface morphologies aud surface · OH concentration of TiO2 films. The samples with a higher polycrystalline anatase structure, rough surface and high · OH concentration displayed a better photoinduced hydrophilicity aud a stronger photocatalysis.

One POM-based Coordination Polymer with 2,6-Bis(1-imidazoly) Pyridine as the Ligand: Synthesis, Structure and Characterizations

One new polyoxometalate-based coordination polymer with 2,6-bis(1-imidazoly)pyridine(L)as the ligand,[Ni(L)(HL)(H2O)(H2 W12O40)0.5·H2O]n,has been synthesized under hydrothermal method and characterized by IR spectra,single-crystal X-ray diffraction,powder X-ray diffraction(PXRD),elemental analyses and thermogravimetric analyses(TGA).It crystallizes in orthorhombic,space group Pnma with a=20.169(7),b=23.924(8),c=15.333(5)?,V=7398(4)?3,Z=8,F(000)=6992,Dc=3.488 Mg/m3,Mr=1942.32,μ=19.177 mm-1 and the final R=0.0299,wR=0.0551.In the title compound,each Ni(Ⅱ)atom is bridged by two ligands L to form Ni2L2,which are further connected into a one-dimensional chain structure by coordination with[H2W12O40]6–polyoxoanions,and thus the ultimate 3D framework is constructed via different hydrogen bonding interactions.In addition,the cyclic voltammograms,magnetism,luminescence and photocatalytic activity towards RhB are investigated.The title compound exhibits antiferromagnetic behaviors,luminescent behaviors at solid state and photocatalytic activity to RhB.