The visible light photocatalytic performance of g-C3N4 is regulated by the Brønsted acid site on the mullite surface

Clay minerals are considered promising semiconductor carrier materials due to their unique physical and chemical properties. However, the exact mechanism by which clay minerals interact with semiconductor materials remains unknown. To this end, the present study was conducted to explore the formation of Brønsted acidic sites on the surface of mullite by modulating the cation types in mullite. It was hereby demonstrated for the first time that the presence of Brønsted acidic sites on the surface of clay minerals is conducive to the formation of N vacancies and dopant O in carbon nitride composites (CNM-30). The synergistic effect of N vacancy and doped O increases the specific surface area of CNM-30, enhances the electron-hole separation and transport efficiency, and ultimately makes CNM-30 produce more reactive oxygen species. CNM-30 possesses excellent degradation ability for gaseous phase pollutants (such as NO) and high concentration liquid phase pollutants (such as RhB and TC). Overall, this paper presents a new perspective on the design and development of semiconductor materials based on clay minerals.