Synthesis, characterization, and photocatalytic properties of ZnO/(La,Sr)CoO3 composite nanorod arrays

Abstract

ZnO/(La, Sr) CoO 3 (ZnO/LSCO) core-shell composite nanorod arrays have been successfully synthesized by a sequential combination process of a hydrothermal synthesis followed by a pulsed laser deposition (PLD) process (or a colloidal deposition process). Compared to the colloidal deposition process, PLD produces a more uniform and efficient deposition of continuous and mesoporous LSCO thin films onto ZnO nanorod arrays. During the PLD process, the deposited film uniformity was found to be dependent on the nanorod diameter, array density, and thus specific surface area of the nanorod arrays, in addition to the PLD deposition parameters. Field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), and X-ray diffraction (XRD) were used to investigate the surface morphologies and orientations of the composite nanorod arrays. With densely packed ZnO nanorod arrays as a unique support structure, the mesoporous LSCO thin film coated on top exhibited better photocatalytic properties than ZnO nanorod arrays and LSCO thin films deposited on flat Si substrates. With optimization of the structure, dimensionality, packing density, as well as the composition and interface structure, these unique composite nanoarchitectures could be a promising class of photocatalyst candidates for organic molecule degradation. Experimental ZnO nanorod array growthThe films of ZnO nanorod arrays were grown on substrates using the hydrothermal method. The substrates used in our experiments included (100) silicon wafer and glass solid substrates. Acetone was used to clean the substrates in an ultrasonic bath. Deposition of ZnO nanorod thin films was achieved using aqueous solutions of zinc acetate (ZnAc 2 , 0.025 mol dm À3 ) and

Hierarchically nanostructured materials for sustainable environmental applications

“…[Reprinted with permission of reference Jian et al (2009). Copyright 2009 Royal Society of Chemistry].…”

Epitaxial growth of group III-nitride films by pulsed laser deposition and their use in the development of LED devices

“…metals, carbon, and numerous more complex systems including oxides and other ceramics, ferroelectrics, high-Tc superconductors and materials exhibiting giant magneto-resistance), and on a wide variety of substrates, at even room temperature [26]. It is relatively clean and generally of low cost, and allows in-situ deposition of multiple compositions [27]. Due to its ability to reproduce the stoichiometry of the ablated target very well, multiple targets sequential PLD has the capability to control the growth by varying parameters such as the laser energy, the pulse repetition rate and fluency (i.e.…”

“…So far, researchers have proven that pulsed laser deposition (PLD) provides large kinetic energy and assists the migration of the precursors on the surface, and thereby makes the film growth at low temperature possible [7][8][9][10][24][25][26][27]. Actually, PLD is now established as one of the simpler and more versatile methods of growing thin films of a very wide range of materials (e.g.…”

Synthesis and Photocatalytic Property of SnO₂/ZnO Nanorod Composites

“…The design and modification of semiconductor photocatalysts with high sensitivity and reactivity have attracted a great deal attention. Several reports have shown that coupling different semiconductor oxides with different band energies would improve the photocatalytic efficiency by increasing effectively electronhole pair separation and extending the photo-responding range [5,15,16]. A large variety of coupled polycrystalline or colloidal semiconductor systems, in which the particles adhere to each other to form "sandwich structure" or present in "core-shell geometry", have been prepared for photocatalytic reactions [3,5,[16][17][18][19].…”