ZnO–SnO2–Sn nanocomposite as photocatalyst in ultraviolet and visible light

Abstract

By combining ZnO with SnO2, it is possible to obtain a photocatalyst with an extended lifetime and increased activity range in both ultraviolet and visible light. The paper presents the synthesis of ZnO–SnO2–Sn nanocomposite. The morphology and structure of the samples were characterized by XRD, FTIR, SEM–EDS and TEM–EDX analysis. The results showed that the synthesised nanocomposites consisted of hexagonal ZnO, cubic SnO2 and Sn nanoparticles. The results revealed that the highest removal efficiency (15.0%) of rhodamine B under visible light was achieved with ZnO–SnO2–Sn consisting of 10% of SnO2 and 5% of Sn, whereas the highest removal efficiency of methylene blue (95.6%) under UV light was achieved with ZnO–SnO2–Sn consisting of 10% of SnO2 and 1% of Sn. The presence of tin nanoparticles enhanced the photocatalytic properties directed towards visible light. The degradation of MB by ZnO–SnO2–Sn remained above 80% even in the 5th cycle, while under visible light during photodegradation the RB removal efficiency decreased from 20 to 14%.

Synthesis of SnO2 and Zn doped SnO2 Nanoparticles by Flame Oxidation Process for Photocatalytic degradation of Methylene Blue Dye

“…Fig. 10 represents the graph plotted between Ct/Co versus time, which clearly indicates the degradation of MB dye by SnO2 and Zn:SnO2 nano-photocatalysts [2]. Accordingly, increase in surface area and band gap can be the reason for the enhancement of photocatalytic activity of the Zn:SnO2 catalysts.…”

“…When Zn is doped there arises three characteristic peaks representing the presence of zinc in the SnO2 lattice [9,19]. Table (1) and (2) shows the weight and atomic percentages of elements that are present in both the synthesized nanomaterials. From the tables it was clear that the oxygen and Sn percentage was considerably decreased due to the addition of Zn dopant.…”

“…Fig. 8(a) shows the MB dye degradation in the presence of SnO2 nanoparticles, before irradiating the MB solution it was tested without any catalyst(blank test) and with the catalyst in dark which exhibits very low photolysis [2]. When the uv radiations falls on the surface of SnO2, it absorbs the radiation and induce electrons from the lower energy level (valence band) to the higher energy level (conduction band) which results in the formation of highly reactive hydroxyl (OH -) radicals and superoxide radicals (O 2-) [16].…”

“…The photocatalytic degradation activity of pure SnO2 and Zn:SnO2 nanoparticles as catalysts on Methylene blue (MB) irradiated under UV radiation were evaluated by the decolorization of MB aqueous solution [2]. A 125 mW/cm 2 (40 W) UV lamp was used as the uv light source to induce the photocatalytic process.…”

“…Mainly, industrial effluent reflects its impact on human life due to its presence in the ecosystem. Generally, most industries produce effluents while producing products, among which the textile industry is the one that generates dyes [2]. Dyes are one of the main pollutants that create environmental risks for all the living organisms in the earth.…”