Photocatalytic Hydrogen Evolution Using Bi-Metallic (Ni/Pt) Na2Ti3O7 Whiskers: Effect of the Deposition Order

Luis F. Garay-Rodríguez, S. Murcia-López, T. Andreu, Edgar Moctezuma, Leticia M. Torres-Martínez, J. R. Morante
2019 Catalysts  
Photocatalytic hydrogen production through ethanol photo-reforming using Na2Ti3O7 whiskers increases if the sodium titanate is decorated with well-known metallic catalysts such as Ni and Pt. Whereas wet impregnation with nickel gives only a slight increase in the activity, photo-deposition of Pt increased the H2 production by more than one order of magnitude. Through the combination of both co-catalysts (Ni and Pt) a superior performance in terms of H2 production is further observed. However,
more » ... drogen yield is largely enhanced (almost three-fold), up to 778 μmol·g−1·h−1, if the Pt is photo-deposited on the surface of the catalyst before wet impregnation with Ni species (NTO/Pt/Ni) compared to H2 yield (283 μmol·g−1·h−1) achieved with the catalyst prepared in the reverse order (NTO/Ni/Pt). Structural, morphological, optical, and chemical characterization was carried out in order to correlate physicochemical properties with their photocatalytic activity. The X-ray photoelectron spectroscopy (XPS) results show a higher concentration of Pt2+ species if this metallic layer is under the nickel oxide layer. Moreover, X-ray diffraction patterns (XRD) show that Na2Ti3O7 surface is modified for both metal decoration processes.
doi:10.3390/catal9030285 fatcat:p3quzagqzbflldxvrx3zo2g6dq