Role of CxNy-Triazine in Photocatalysis for Efficient Hydrogen Generation and Organic Pollutant Degradation Under Solar Light Irradiation

A critical drawback of existing materials, which restricts the photocatalytic efficiency, is the fast recombination of charge carriers. To address this challenge, loading reduction and oxidation co-catalysts on two opposite surfaces of a hollow semiconductor is a critical approach to improve the photocatalytic performance. These co-catalysts mainly act as oxidation and reduction active sites, while suppressing the charge recombination. Moreover, the development of a novel and efficient co-catalyst that boosts charge separation is a very important feature for the photocatalytic performance. Herein, we report the first synthesis of hollow Pt/TiO2/CxNy-triazine nanocomposite using carbon colloidal spheres as a hard template, in which Pt and CxNy-triazine are located on the two opposite hollow surfaces. CxNy-based triazine species formed from cyanamide during calcination do not only stabilize the hollow structure and significantly enhance the surface area of Pt/TiO2/CxNy-triazine, but also act as an efficient oxidation co-catalysts. This new type of nanocomposite exhibits one of the best TiO2-based photocatalysts working under solar light irradiation to date. It is 125 and 62 times higher than that of Pt/TiO2-P25 for hydrogen generation and methanol decomposition, respectively.