Sunlight active g-C3N4-based Mn+ (M[dbnd]Cu, Ni, Zn, Mn) – promoted catalysts: Sharing of nitrogen atoms as a door for optimizing photo-activity

Abstract

In this work we analyze the photocatalytic performance of Mn+ (M[dbnd]Cu, Ni, Zn, Mn) - g-C3N4 materials in toluene photo-oxidation under UV and Sunlight-type illumination conditions. The characterization of the solids showed that Cu and Mn containing samples have an oxide type environment, while Ni has a hydroxide type and Zn shows an oxynitride type local order. The photo-activity of the samples under UV and sunlight excitation(s) was evaluated in terms of activity and selectivity, and the subsequent calculation of the quantum efficiency. Optimum activity was obtained with the Zn-containing catalyst. The charge carrier(s) handling and fate through interfaces and recombination was measured and correlated with the structural characterization of the solids. This indicates that the interface contact between the Zn oxynitride and carbon nitride components has significant influence in charge carrier processes and it is at the core of the good photocatalytic properties owned by this sample.