RESUMO
Photocatalytic nanofibers of TiO2 decorated with 2% metal (Pt, Pd, and Cu) and metal alloys (Pt2Pd and PtCu) were synthesized by the polymer-assisted electrospinning method, followed by microwave-assisted ethylene glycol reduction. Structurally, nanofibers calcined at 500 °C adopted an anatase phase along with a remnant rutile phase. Morphological, structural, and photocatalytic studies were carried out using scanning and transmission electron microscopy equipped with an energy dispersive spectroscopy attachment, X-ray powder diffraction, X-ray photoelectron spectroscopy, and photocatalytic hydrogen generation under UV-Vis irradiation. The calcined nanofibers were found to have a diameter of 60.0 ± 5.0 nm and length of up to several microns. High resolution TEM imaging suggests that the nanofibers are composed of agglomerated individual TiO2 nanoparticles, which are tightly packed and stacked along the axial direction of the nanofibers. PXRD studies suggest alloy formation, as evident from peak shifting towards higher two-theta values. Surface modification with co-catalysts is shown to contribute considerably to the rate of photocatalytic H2 generation. The amount of H2 generated gradually increases as a function of time. The 2%Pt2Pd/TiO2 catalyst shows the highest rate of H2 generation (4 mmol h-1 gramcatalyst), even higher than that of 2%Pt/TiO2 nanofiber photocatalyst (2.3 mmol h-1 gramcatalyst), while 2%Cu/TiO2 nanofiber photocatalyst shows the least activity among the decorated catalysts (0.04 mmol h-1 gramcatalyst).
