A novel high-photoactivity quaternary ZnSn(OH)6–graphene composite evolved from a 3D multilayer structure via a facile and green proton-mediated self-assembly method

Abstract

A novel chemically bonded ZnSn(OH)₆ (ZHS) nanocube (NC)–graphene (GR) nanosheet (NS) (ZHS–H–GR) composite, with a quaternary architecture evolved from a ZHS/GR/ZHS-multilayer structure, is obtained successfully via a facile, green and efficient proton-mediated electrostatic self-assembly approach, followed by a mild photoreduction process. The as-synthesized ZHS–H–GR is made up of some chemical bonds with conjugative effects in the interface, which play the role of electronic transmission channels during the photocatalytic process. This chemically bonded linkage is able to promote the separation of photo-generated hole (h⁺)–electron (e⁻) pairs under UV irradiation, resulting in a superior photocatalytic performance of methyl orange (MO) molecules and rhodamine B (RhB) compared with that of the bare ZHS. The photocatalytic reaction rate of the photo-degradation of MO is 1.94 times and 1.74 times higher than that of pristine ZHS and commercial P25, respectively. For the photocatalytic degradation of rhodamine B (RhB), ZHS–H–GR gives a 4.37 times higher reaction rate than for the bare ZHS. It is expected that the present synthetic strategy may provide a new design concept for the fabrication of various GR-involved hybrids with multi-dimensional structures and controllable morphologies.