The Preparation And Catalytic Properties Study Of Metallic Oxide/Titanate Nanowires Composite Materials

In this paper, we designed a recyclable and highly active porous catalyst oftitanate nanowires (TNWs) coated with well-distributed Co3O4nanoparticles (NPs) orNiO nanosheets to obtain composite nanomaterials. Sodium ions of TNWs wereexchanged with hydrogen ions in the dilute nitric acid, and this protocol was verysuitable for capturing cobalt and nickel ions.X-ray diffraction (XRD) demonstrated the existence of Co3O4phase with uniquelattice planes such as (220),(311) and (511), and the unique lattice planes of NiOcrystal like (111),(200) and (220) occurred. Electron microscopes (FE-SEM and TEM)indicated that the Co3O4NPs with an average diameter of223nm were coateduniformly on TNWs surface (average diameter:375.5nm), and the Co3O4NPsmainly exposed their (220) and (222) active planes. XPS analysis confirmed theformation of Co3O4phase by the presence of Co2p peaks at780.1eV (2p3/2) and795.5eV(2p1/2). The binding energy of Ni2p3/2at853.6eV indicated the valencestate of Ni were+2, which demonstrated the Ni compounds in composite materialswere NiO.Methyl blue (MB) and other organic dyes (rhodamine B (RhB) and methylorange (MO)) were acted as target compounds for the degradation of Co3O4/TNWsunder indoor scatting light. Compared to the original Co3O4/TNWs catalyst, thecatalytic efficiency of0.1g nanosized catalyst with oxone for MB degradation wasabout15times higher, and the MB solution (200mL,10mg L-1) was completelycleaved within10minutes. The catalytic activity of recycled catalyst used in the sixthrun still remained very active, and the degradation time for MB was only16minutes.The nanosized catalyst also had a high activity for dyes of RhB (200mL,10mg L-1)and MO (200mL,10mg L-1), and the degradation efficiencies of RhB and MO after10minutes of contact time were about90.2%and92.6%, respectively. Methyleneblue trihydrate was acted as the degradation target for NiO/TNWs.0.5g NiO/TNWscan degrade96%dye in the diluted solution of methylene blue trihydrate (200mL, 10mg/L) in40minutes. The degradation ratios of recycled catalyst from1thto5thrunswere96%,90%,82%,65%and54%respectively.The merits of as-prepared catalysts such as Co3O4/TNWs and NiO/TNWs areeasy to recycle run by run, and they nearly do not cause the secondary pollution.Meanwhile, the nanosized catalysts are very cost effective, conveniently to operate,and environment friendly for the organic dyes degradation.