Coral-inspired nanoscale design of porous SnS2 for photocatalytic reduction and removal of aqueous Cr (VI)

- A unique porous corallite-like nanocomposite was fabricated for catalytic reduction and removing water-soluble Cr ions.
- The “corallite” exhibited high visible-light catalytic activity and high adsorption capacity under UV light irradiation.
- The compounds on the surface of “corallite” can selectively chelate aqueous Cr (III) by exposing to ultraviolet light.
- The nanocomposite can effectively reduce and remove aqueous Cr (VI) (less than 50 mg/L) with an efficiency of nearly 100%.

Frequent industrial discharge of various contaminants such as heavy metals into water resources has caused severe environmental damage. In this study, a unique porous corallite-like nanocomposite (SPNH-MOSF@SnS2) was successfully fabricated via surface modification of visible-light-driven photocatalyst (SnS2) and chelating ligand (spirobenzopyran derivative, SPNH) on macroporous ordered siliceous foam (MOSF). In our approach, SnS2 was selected as the photocatalyst due to its high visible light induced photocatalytic activity. SPNH was modified because it could selectively chelate soluble Cr (III) when exposed to ultraviolet light. This unique nanocomposite could be used for highly efficient reduction and removal of hexavalent chromium [Cr (VI)] from wastewater, especially under the mildly acidic condition. The results indicate encouraging applications of this as-prepared new nanocomposite for treating Cr (VI) containing wastewater.

168SnS2 nanocrystals were successfully encapsulated in macroporous ordered siliceous foam decorated with spirobenzopyran derivative and employed for highly efficient photocatalytic reduction and removal of hexavalent chromium from water.