g-C3N4 Monolayer/2D Mica Nanohybrids with Highly Effective UV–HEV-Screening Function

Excessive exposure to ultraviolet (UV) and high-energy visible (HEV) light can cause sunburns, wrinkles, and even skin cancer. Therefore, the development of effective UV–HEV-shielding agents is of great importance to human health. In this study, semiconducting graphitic carbon nitride (g-C3N4) is incorporated into the interlayer space of mica through the intercalation of cyanamide and subsequent pyrolysis reactions to form a semiconductor–insulator nanohybrid, namely g-C3N4–mica, with a 1:1 heterostructure. The g-C3N4–mica nanohybrid exhibits excellent UV–HEV absorption properties below 450 nm, and its photocatalytic activity is quenched owing to the effective screening of photocatalytic active sites by the insulating mica. It is strongly believed that the proposed g-C3N4–mica nanohybrid can be applied as a UV–HEV blocking agent owing to its excellent UV–HEV (200–450 nm)-screening property without any photocatalytic effect or phototoxicity.