SnO2 Composite Films for Enhanced Photocatalytic Activities

Abstract

As a new type of promising semiconductor photocatalyst, SnO2 cannot be widely applied due to its low utilization efficiency to visible light and swift recombination of photogenerated electrons and holes. These drawbacks were effectively overcome by preparing the B/Ag/F tridoped SnO2-ZnO composite films using the simple sol–gel method. The degradation of the methyl green and formaldehyde solutions was used to value the photocatalytic activity of the samples. Photoluminescence (PL) spectra and the UV–Vis absorption spectroscopy results of the samples illustrated that the B/Ag/F tridoped SnO2-ZnO composite film not only improved the lifetime of the charge carriers, but also enhanced their visible light absorption. The X-ray diffraction (XRD) results showed that the crystalline SnO2 was in the structure of rutile. As exhibited in the BET surface area results, the specific surface area of pure SnO2 was 19.9 m2g−1, while that of the B/Ag/F tridoped SnO2-ZnO was 85.3 m2g−1. Compared to pure SnO2, SnO2-ZnO, or the mono- or di-doped SnO2-ZnO films, the B/Ag/F tridoped SnO2-ZnO composite film had the highest photocatalytic activity.

Enhancement of Photocatalytic Activity for Nanostructured ZnO Thin Film Prepared by Pulsed Spray Pyrolysis

“…Rotatable (PSP) system with (On/ Off-mode) keeps the substrate temperature constant which promote the adhesion between the substrate and the deposited layers, permits enough time for film growth and homogeneity improvement. The substrate / nozzle distance isfixed at 30 cm with a solution flow rate of 5 ml / 2 min during different spray times (5,10,15 The structural properties of the deposited samples are examined by Grazing angle X-ray diffraction technique (GAXRD -Diano corroboration-USA equipment with Cu K α radiation of λ= 1.514 Å) to clarify the structure, crystallite size and to recognize the appeared phases of the investigated samples. The surface topography and film thickness are explored by scanning electron microscopy (SEM).…”

“…Optical measurements (transmittance and reflectance spectra) are performed by double beam spectrophotometer (JASCO-670 UV-VIS-NIR) in wavelength range from 0.2 to 2.5 µm. ZnO film deposited at 500 o C and a spray time of 25 min is selected for selective etching by immersing the ZnO supported glass substrate in much diluted potassium hydroxide (KOH) solution of 50 mM for 5 minutes in water bath at 80 o C. This chemical etching process is widely used because it is simple and efficient way to change the surface morphology of thin film structure [5,6].Then, photocatalytic activities are evaluated for the etched and non-etched ZnO samples. Photodegradation test was executed by immersing both of the etched [6] and non-etched ZnO thin films into 5 ml of MB [C 16 H 18 ClN 3 S] aqueous solution (10 mg/L) under illumination by a UVpen lamp (λ max = 254 nm and power 5 mW/cm 2 ).…”

“…Several metal oxides such as TiO 2 , ZnO, SnO 2 and CeO 2 are reported in literature as photocatalyst [3][4][5][6][7]. To select the proper and high performance photocatalyst energy gap, separation and life time of photo generated e/h pairs, abundance and simple preparation technique should be considered [8][9][10].…”

Tridoped TiO2 Composite Films for Improved Photocatalytic Activities

“…Then, we prepared 0.02 mol/L NaOH ethanol solution (B solution) by dissolving 0.008 g NaOH in 10 mL absolute ethanol. Lastly, in a volume ratio of 1/9, we added B solution to A solution with stirring for half an hour [23]. After three days aging, ZnO sol would be obtained.…”

Tri-doped co-annealed zinc oxide semi-conductor synthesis and characterization: photodegradation of dyes and gas sensing applications

“…Han et. al [10] found that B/Ag/F tridoped SnO2-ZnO film is attributed to the low recombination rate of electron-hole pairs. The C-N-S doped TiO2 was observed for the highest photocatalytic activity for Rhodamine B degradation under visible illumination irradiation [11].…”