Facile hydrothermal synthesis and photocatalytic properties of g-C3N4/Cu3TeO6 heterostructures

Abstract

In this work, we have developed, for the first time, heterostructures based on Cu₃TeO₆ (CTO) with a strong interaction with a well-studied g-C₃N₄ (GCN) semiconductor. This has been carried out to mitigate the drawbacks of CTO for its application as photocatalyst in H₂ production. In this sense, the resulting heterostructure presented higher activity than the pure CTO and GCN (113, 85, and 42 µmol_H2/mg, respectively). The methodology employed to synthesise the heterostructure was a hydrothermal synthesis on the surface of GCN to ensure a strong interaction between both materials by growing the CTO crystal in presence of GCN. The physicochemical characterisation of the materials by XRD TG, SEM, TEM, and FTIR revealed that the synthesis was successfully developed and that Cu₃TeO₆ grew on the g-C₃N₄ surface. Indeed, this novel synthesis of the heterostructure based on CTO has huge interest for its application in H₂ production due to the redox capability of the materials, observed by UPS and UV–Vis spectroscopies. The enhancement of the catalytic activity of the heterostructure with respect to the pristine materials was associate to the strong interaction between both components, the catalytic effect of Cu species, and the improved charge transfer. Indeed, a lower e⁻ − h⁺ pair recombination rate was observed by steady PL analysis with respect to the pristine GCN material. These results indicate that it is possible to synthesise heterostructures based on metal tellurates with improved catalytic activity of the mixture with respect to the pristine material in a relevant energy application such as H₂ production.