Precursor-Derived Rare Earth Metal Pyrochlores: Nd₂Sn₂O₇ Nanofibers and Thin Films As Efficient Photoabsorbers

Abstract

Single phase rare earth pyrochlores, Ln2M2O7, were produced as nanofibers and thin films by electrospinning and spin-coating of chemical sols obtained from bimetallic metal–organic precursors, LnIIIMII(OtBu)5Py (LnIII = La, Pr, Nd, Sm, Er, Yb; MII = Ge, Sn, Pb; Py = pyridine). Compatibility of the metal ratio in the single-source compounds was confirmed by single crystal X-ray diffraction analyses and the ratio was preserved during the processing as the crystalline pyrochlore materials originated from an amorphous preceramic aggregate as confirmed by powder XRD and TEM studies. The photocatalytic activity of the Nd2Sn2O7 nanofibers was found to be significantly higher than that of TiO2. Nd2Sn2O7 thin films deposited on F:SnO2 as bilayered Nd2Sn2O7//Fe2O3 photoanodes showed superior photoelectrochemical (PEC) efficiency for water splitting reaction with an over 3-fold higher photocurrent density than bare Fe2O3 photoanodes.