UV‐visible absorption and photoluminescence characteristics of SnO₂ nano‐tube/wire arrays fabricated by LPD method

Abstract

In this study, SnO2 nano‐tube/wire arrays with a diameter in the range of 90‐120 nm and several micrometers in length were synthesized by the liquid phase deposition (LPD) method. The study of structural properties was performed by XRD, Raman and TEM, while the optical properties were measured using UV‐visible absorption and photoluminescence spectroscopy. The Raman spectra of the nano‐tubes/wires revealed the presence of 5 vibration peaks assigned to the tetragonal rutile SnO2 structure in agreement with the XRD results. The estimated optical direct band gap from UV‐visible absorption spectra was found to be 3.73‐3.88 eV. The observed blue shift of the optical band gap can be explained by the higher formation of mesoporous particles on the exposed surface to the photons. The photoluminescence (PL) spectra of the nano‐tubes/wires exhibited a rather broad and intense emission band centered at around 560‐569 nm.

Template Based Synthesis of Plasmonic Ag‐modified TiO2/SnO2 Nanotubes with Enhanced Photostability for Efficient Visible‐Light Photocatalytic H2 Evolution and RhB Degradation

“…There is a significantly red-shift in absorption band edge toward the visible-light region, as well as, an increase in absorbance for TiO 2 /SnO 2 nanotube and Ag-TiO 2 /SnO 2 nanotube composites when compared to SnO 2 and TiO 2 nanotubes. On the basis of the UV-vis DRS results and Tauc relation, [44,45] the bandgaps of SnO 2 , TiO 2 , TiO 2 /SnO 2 , 0. RhB is a typical fluorescent marker dye indicating absorbance around 550 nm due to intramolecular π!π* transitions.…”

“…There is a significantly red‐shift in absorption band edge toward the visible‐light region, as well as, an increase in absorbance for TiO 2 /SnO 2 nanotube and Ag‐TiO 2 /SnO 2 nanotube composites when compared to SnO 2 and TiO 2 nanotubes. On the basis of the UV‐vis DRS results and Tauc relation, the bandgaps of SnO 2 , TiO 2 , TiO 2 /SnO 2 , 0.2 Ag‐TiO 2 /SnO 2 , 0.4 Ag‐TiO 2 /SnO 2 and 0.5 Ag‐TiO 2 /SnO 2 nanotubes was estimated be 3.76, 3.09, 2.90, 2.82, 2.72 and 2.87 eV, respectively. The determined energy bandgap of hybrid TiO 2 /SnO 2 nanotubes are lower than that of SnO 2 and TiO 2 .…”

Enhanced photocatalytic hydrogen evolution by novel Nb-doped SnO2/V2O5 heteronanostructures under visible light with simultaneous basic red 46 dye degradation

“…Figure 7a shows the PL spectra of SnO 2 nanotubes, SnO 2 /V 2 O 5 , 0.5, 1.0, 2.0, and 4.0Nb-doped SnO 2 /V 2 O 5 heteronanostructures, where the SnO 2 nanotubes exhibit an obvious PL emission signal around 568 nm. This broad green peak can be related to the presence of surface defects such as oxygen vacancies, which provide acceptor levels below the conduction band edge [40]. There is a reduction in the PL intensity with the anchoring V 2 O 5 nanoparticles onto SnO 2 nanotubes, demonstrating the constructive effect of heterojunctured structures in facilitating chargeseparation.…”

Photocatalytic degradation evaluation of N-Fe codoped aligned TiO2 nanorods based on the effect of annealing temperature

“…Although several template-based techniques such as electrophoretic deposition [19], sol-gel synthesis [20], chemical vapor deposition (CVD) [21], ALD [22], etc., have been employed to fabricate 1D TiO 2 nanostructures, liquid-phase deposition (LPD) process has been shown to be especially versatile synthesis procedure. This method is one of the simplest and most practical ones, since it has so many advantages such as mild reaction condition, high degree of control, simple equipment requirement, low cost, desired size and morphology, and allows TiO 2 films to be deposited over large areas [23,24]. TiO 2 -rod shape has light scattering effect and can decouple the directions of light absorption and charge carrier collection.…”