Rational Fabrication of MoS 2 /g‐C 3 N 4 Heterostructures for Efficient Photocatalytic Degradation of Rhodamine B

Abstract Molybdenum disulfide (MoS 2 ) and graphitic carbon nitride (g‐C 3 N 4 ) heterojunctions were prepared through the hydrothermal method and the calcination method (namely, MoS 2 /g‐C 3 N 4 ‐1 and MoS 2 /g‐C 3 N 4 ‐2) for the photocatalytic degradation of Rhodamine B. X‐ray diffraction and scanning electron microscopy confirmed the formation of a heterostructure composite between MoS 2 and g‐C 3 N 4 . The bandgap of MoS 2 and g‐C 3 N 4 was studied with ultraviolet–visible diffuse reflection spectroscopy and electrochemical Mott‐Schottky tests. MoS 2 /g‐C 3 N 4 ‐1 exhibits remarkable efficiency in degrading Rhodamine B, achieving 91.2 % degradation in 1 h, which is 1.06 times higher than MoS 2 /g‐C 3 N 4 ‐2. Additionally, the MoS 2 /g‐C 3 N 4 ‐1 heterojunction demonstrates good reusability, maintaining a degradation efficiency of 71.2 % after 5 cycles. The reason lies in that the MoS 2 /g‐C 3 N 4 ‐1 possesses a larger specific surface area (33.078 m 2 g −1 ) than MoS 2 /g‐C 3 N 4 ‐2 (28.621 m 2 g −1 ). Free radical quenching experiments indicate that ⋅O 2 − serves as the primary active species for photocatalytic degradation. The findings indicate that incorporating g‐C 3 N 4 into MoS 2 improves its photocatalytic capability due to aligned energy bands, promoting charge transfer, and reducing electron‐hole recombination.