Enhanced photoelectrochemical water splitting and mitigation of organic pollutants under visible light with NaNbO3@CuS Core-Shell heterostructures

Abstract

We have synthesized new NaNbO3@CuS core-shell heterostructures by an ion-exchange based hydrothermal method. The powder X-ray diffraction (PXRD) analysis revealed the orthorhombic and hexagonal phase of NaNbO3 and CuS, respectively. The photocatalytic efficiency using these heterostructures is a manifestation of high surface area, appropriate band alignment and increased range of light harvesting. The core-shell materials show significant photocatalytic activity towards photoelectrochemical water splitting and degradation of Rhodamine B (RhB) organic dye considered as a model pollutant for study under visible light illumination. The photoelectrochemical (PEC) measurements using these core-shell heterostructure as photocathodes, characterized by high photocurrent density of ∼ 4.87 mA/cm2 at ̶0.648 onset potential versus Ag/AgCl. Mott-Schottky analysis indicates the p-n junction feature of NaNbO3@CuS core-shell heterostructures which facilitate the interfacial separation of photogenerated charge carriers. Furthermore, the longer life time of charge carriers of the core-shell heterostructures (20 twenty times larger τave as compared to bare CuS) revealed the higher photocatalytic efficiency.

Keywords

• NaNbO3@CuS core-shell
• Heterostructure
• Interfacial charge transfer
• Photocatalysis
• Photoelectrochemical studies