Photochemical deposition of SnS2 on graphitic carbon nitride for photocatalytic aqueous Cr(VI) reduction

Abstract

Cost-effective and efficient photocatalysts are in demand for high-performance clean energy and environmental technologies. In this article, we report the synthesis of 2D/2D SnS2/g-C3N4 layered heterostructures with reduced interfacial resistance and improved charge transfer kinetics via a photochemical deposition method. The SnS2/g-C3N4 catalysts demonstrate outstanding photocatalytic Cr(VI) reduction (with a 21.2 μmol h–1 Cr(VI) consumption rate) and water oxidation (with a 15.1 μmol h–1 O2 evolution rate) activity, reaching energy conversion efficiencies of up to 16.4% and 12.1% at 375 nm and 410 nm, respectively, that is among the best known Cr(VI) reduction catalysts reported to date. Based on X-ray photoelectron and UV–vis/NIR absorption spectroscopy, and electrochemical and photoelectrochemical measurements, we provide a mechanistic understanding of the redox reactions and charge transport dynamics in this catalytic system. The results demonstrate the potential viability of the SnS2-decorated g-C3N4 nano-heterostructures for environmental remediation applications, including decontamination of Cr(VI)-polluted aquatic systems.

Keywords

• Tin disulfide
• Carbon nitride
• Layered heterostructures
• Photocatalytic Cr(VI) reduction
• Environmental chemistry