NH4Cl-assisted in air, low temperature synthesis of SnS2 nanoflakes with high visible-light-activated photocatalytic activity

This communication reports a viable low temperature method for scalable production of SnS2 nanomaterials with promising applications in visible-light photocatalysis and photovoltaics. SnS2 nanoflakes were synthesized via heating the mixture of NH4Cl, S and Sn powders in air at 250 °C for 2 h, followed by a washing process. X-ray diffraction, scanning electron microscope, and nitrogen adsorption-desorption isotherms characterization indicated the formation of pure SnS2 nanoflakes with a specific surface area of 32.081 m2/g. Comparative synthesis experiments manifested that NH4Cl played an indispensable role in our low temperature synthesis of SnS2. UV-vis absorbance spectrum demonstrated that the as-synthesized SnS2 nanoflakes had much higher absorption of visible-light than hydrothermally synthesized SnS2 and thermally exfoliated g-C3N4. Transient photocurrent measurements and photocatalytic tests indicated that our product had not only exceptionally larger photocurrent, but also significantly higher photocatalytic activity than hydrothermally synthesized SnS2 and thermally exfoliated g-C3N4 in the reduction of Cr(VI) under visible-light (λ > 420 nm) irradiation.