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

• GCN/CTO heterostructure was successfully synthesised for first time. • GCN/CTO heterostructure has a strong interaction between both semiconductors. • GCN/CTO heterostructure has higher activity than the individual materials. • This work is a proof of concept for the use of CTO/GCN for energetic applications. In this work, we have developed, for the first time, heterostructures based on Cu 3 TeO 6 (CTO) with a strong interaction with a well-studied g-C 3 N 4 (GCN) semiconductor. This has been carried out to mitigate the drawbacks of CTO for its application as photocatalyst in H 2 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 Cu 3 TeO 6 grew on the g-C 3 N 4 surface. Indeed, this novel synthesis of the heterostructure based on CTO has huge interest for its application in H 2 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 H 2 production.