Size-Tunable Hydrothermal Synthesis of SnS₂ Nanocrystals with High Performance in Visible Light-Driven Photocatalytic Reduction of Aqueous Cr(VI)

Abstract

SnS(2) nanocrystals with adjustable sizes were synthesized via a hydrothermal method from the aqueous solution of common and inexpensive SnCl(4)·5H(2)O, thioacetamide and citric acid, simply by varying the reaction temperature and reaction time. The structures, Brunauer-Emmett-Teller (BET) specific surface areas and optical properties of the resultant SnS(2) nanocrystals were characterized by X-ray diffraction, transmission electron microscopy, N(2) adsorption/desorption isotherms, and UV-vis diffuse reflectance spectra. Besides, their photocatalytic properties were tested for the reduction of aqueous Cr(VI) under visible light (λ > 420 nm) irradiation. It was found that the photocatalytic activities of SnS(2) nanocrystals in aqueous suspension depended on their synthesis conditions. The product synthesized under suitable hydrothermal conditions (for example, at 150 °C for 12 h) not only showed high visible light-driven photocatalytic activity in the reduction of aqueous Cr(VI), but also showed good photocatalytic stability. Our photocatalytic results suggested that SnS(2) nanocrystals are a promising photocatalyst in the efficient utilization of solar energy for the treatment of Cr(VI)-containing wastewater.

Photoelectrochemical cell for simultaneous electricity generation and heavy metals recovery from wastewater

“…However, current laboratory studies have not been translated to real applications in wastewater treatment, since the hole scavengers are often relatively costly reagents such as methanol and NaHCO 3 [12] which makes their use unrealistic in industry. Early studies performed with suspensions of nanoparticle photocatalysts [13][14][15][16] were not practical, since the separation of the suspended catalyst from the aqueous suspension, and of the metals from the solid, are highly challenging [17].…”

Photocatalytic Reduction of Aqueous Cr(VI) with CdS under Visible Light Irradiation: Effect of Particle Size

“…In general, the studies covered many aspects of photocatalysis includ-ing the influence of the (a) type of photocatalyst [4,5,6,7], (b) irradiation intensity [8], (c) photocatalyst loading [9], (d) Cr(VI) pollutant concentration [9], (e) solution pH [10], and (f) addition of radical scavengers [11] on the rate of reduction of Cr(VI) to Cr(III) with the objective of optimizing the process. The findings indicate that (a) the rate of reduction increases but photoefficiency decreases with increasing irradiance, (b) the percentage of Cr(VI) photoreduced increases to a maximum and then decrease with increasing photocatalyst loading, (c) the rate of reduction increases but percentage of Cr(VI) reduced decreases with increasing Cr(VI) concentration, and (d) the rate of reduction decreases with increasing pH.…”

Controllable Synthesis of Zn2GeO4Nanorods for Photocatalytic Reduction of Aqueous Cr(VI) and Oxidation of Organic Pollutants

“…It is highly mobile in water and exhibits a high toxicity and carcinogenicity for environment and human beings [1,2]. Its concentration in drinking water is restricted to be less than 0.05 mg/L by the World Health Organization.…”