Defected mesoporous carbon nitride with quantum confinement effect for NO purification

Combining mesoporous structure and defect engineering is an effective way to optimize the photocatalytic activity of graphitic carbon nitride. Herein, a unique N-deficient mesoporous carbon nitride (nmpg-C3N4), constructed by silica-template method, possesses efficient and stable photocatalytic purification of NO, far exceeding the bulk carbon nitride (B-C3N4). In nmpg-C3N4, the mesoporous structure not only exposes more active sites, but also the resulting quantum confinement effect widens the band gap of nmpg-C3N4 and enhances its redox ability. While N defects constitute catalytic active sites and induces effective separation of photogenerated carriers. Under the synergistic effect of mesoporous structure and defect engineering, nmpg-C3N4 produces more •O2− and •OH to remove NO in the air. Its photocatalytic activity reaches 60.61% higher than B-C3N4 (35.51%) and exposes better stability. Moreover, a reasonable NO purification path was proposed using in-situ DRIFTS technology. Our research proves that utilizing the quantum confinement effect of mesoporous materials combined with defect engineering can effectively extend the energy band and make the catalyst have more active sites. This study provides new enlightenment for the modification of carbon nitride.