The nano-spherical MoS2(F)/g-C3N4 hetero-junction was successfully synthesized by calcining the thiourea coated MoS2(F), where the thin g-C3N4 nano-sheets were grown on the surface of MoS2(F) nano-sphere. The enhanced photo-catalytic performance and stability of the sample were assessed by degrading the Rhodamine B under the irradiation of sunlight, which could be attributed to the widened spectral absorption range and improved electron–hole separation rate. Based on above results, the photo-catalytic mechanism involving redox reactions was also proposed. [ABSTRACT FROM AUTHOR]