Electrospun metal and metal alloy decorated TiO nanofiber photocatalysts for hydrogen generation.

Photocatalytic nanofibers of TiO decorated with 2% metal (Pt, Pd, and Cu) and metal alloys (PtPd 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 TiO 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 H generation. The amount of H generated gradually increases as a function of time. The 2%PtPd/TiO catalyst shows the highest rate of H generation (4 mmol h gram), even higher than that of 2%Pt/TiO nanofiber photocatalyst (2.3 mmol h gram), while 2%Cu/TiO nanofiber photocatalyst shows the least activity among the decorated catalysts (0.04 mmol h gram).