Highly Selective Visible-Light Photocatalytic Synthesis of Tocopheryl Acetate Over Heterostructured g-C3N4

Conventional syntheses of tocopheryl acetate rely on strong Brønsted/Lewis acids and energy-intensive conditions. Here we report a visible-light photocatalytic route using graphitic carbon nitride (g-C 3 N 4 ) engineered by precursor control, P/S co-doping, metal loading (Cu, V, Zn, Ni), and nanosheet formation. Structural characterization by SEM and TEM revealed that P/S co-doping and exfoliation produced highly corrugated nanosheets with increased porosity, abundant edge sites, and reduced interlayer stacking. XRD analysis confirmed the preservation of the g-C 3 N 4 framework with slight distortion upon doping, while HRTEM showed lattice disorder and defect formation that are beneficial for charge trapping and transfer. In ethanol/H 2 O 2 under a 40 W lamp, P/S@g-C 3 N 4 affords a 76.26% yield with 99.80% selectivity; no formation occurs in the dark. Screening identifies 5 mg mL −1 substrate, 4 mg catalyst, and 45 °C as optimal, while yields decline above 55 °C. The catalyst is reusable for 20 cycles with slight loss from handling. DRS results showed that the absorption capacity of P/S@g-C 3 N 4 to visible light was significantly higher than that of g-C 3 N 4 . And compared with g-C 3 N 4 , the E g value of P/S@g-C 3 N 4 is significantly narrowed form 2.71 eV to 2.42 eV. Mechanistic analysis indicates P/S sites and heterointerfaces enhance H 2 O 2 activation, oxidize ethanol to acetaldehyde, and channel coupling with a phenoxyl intermediate from tocopherol. This acid-free strategy offers a scalable route to tocopheryl acetate.