Controlled Nanoarchitectonics of g-C3N4/ZnO Heterostructures for High-Efficiency Photocatalytic Degradation

A facile one-pot synthesis of g-C 3 N 4 /ZnO heterojunctions is reported for water remediation. The optimal composite (3:7 mass ratio) achieves enhanced visible-light degradation of methylene blue (k = 0.02033 min -1 ), attributed to interfacial charge separation rather than adsorption, as evidenced by PL and photocurrent measurements. Radical trapping and LC-MS identify •OH and h + as dominant species and reveal a stepwise demethylation degradation pathway. DFT calculations verify a type-II band alignment with a built-in electric field that thermodynamically drives carrier separation. The composite maintains excellent stability over multiple cycles, highlighting its potential for practical photocatalytic applications.