New Visible Light Catalyst Nd <sub> 2 </ Sub> Innbo <sub> 7 </ Sub> Preparation, Characterization And Performance Study

With regard to a subject of great interest that the photocatalytic water splitting using solar energy generates clean energy hydrogen, this paper focuses on preparation and characterization of visible light response pyrochlore-type photocatalytic materials and the investigation of their photocatalytic activity for water splitting, which may play an important role in visible light response photocatalyst study.Novel visble light responsible photocatalyst Nd2InNb07 was succeed synthesized via high temperature solidstate reaction method by using high pured Nd2O3, In2O3 and Nb2O5 as raw materials. The catalyst samples were characterized by X-ray diffraction, Laser Raman Spectrum (LRS), Fourier Transformed Infra-Red spectrum (FT-IR).The XRD paterns indicated that the optimal reacting temperature is 1573K, in Nd2InNb07 samples'synthesization. The samples'crystallization was getting perfectly accompany with the inhancement of the reacting temperature. The composition of sample obtained at 1573K was repeatedly estimated to be pure Nd2InNb07 by LRS and FT-IR spectrum, as only characteristic vibrations belongs to Nd-O', M-O (M=In,Nb) and Nd-O bond of Nd2InNbO7 pyrochlore were founded. The Rietveld refine result shows that Nd2InNb07 belongs to cubic crystal system, Fd3m space group, the Interplanar Spacing d=1.06593(4) nm and the Cell Volume V=1.21113 nm3. UV-vis DRS spectrum suggests that Nd2InNbO7 photocatalyst have strong response in visible-light area (400-700nm), The energy gap of Nd2InNbO7 semiconductor was evaluated to be 2.64 eV by mathematics regression of the UV-vis DRS curve.In order to improve the photocatalytic activity, NiOx and noble metals (Pt, Ru, Rh) were loaded onto the surface of Nd2InNbO7 particles with the photodeposition method, which was comfirmed by SEM and TEM morphology analysis. It was also founded that the tiny particles agglomerate heavily when the amount of loading species increased. The experiments resules shows that NiOx and Pt are more suitable, H2 evolution rate of 1.0 wt% NiOx-Nd2InNbO7 and 0.1 wt% Pt-Nd2InNb07 achives 4.62 and 4.50μmol/h, comparing to that unloaed samples'value of 0.41μmol/h.0.1 wt% Pt-Nd2InNb07 was chosen to investigate the photocatalytic activies in the presence of different sacrificial reagent under visible-light, the result shows that the H2 evolution rate of sample in 0.05 mol/L Na2SO3 is highest,8.7μmol/h. Under visible-light irradiation, the photocatalytic activity for water splitting H2 evolution over Nd2InNb07 was higher than that over Nd2Zr207. The relationships between the photocatalytic properties of these photocatalysts and their band structures as well as crystal structures were discussed. The higher photocatalytic activity of Nd2InNb07 was ascribed to its conduction band changing, and the higher level of lattice distortion.