Luminescent polymeric graphitic composites have the potential to be efficient energy converters for sophisticated displays and light sources. Thermal condensation is used to synthesize g-C 3 N 4 -ZnS composites. The XRD, and FTIR analyses confirmed the synthesis of the pure host, filler, and composites. FESEM, and TEM images revealed that the ZnS nanosheets were evenly distributed over the g-C 3 N 4 sheets. The addition of ZnS improves the thermal stability of g-C 3 N 4 . The optimized gZ15 band gap is determined to be 2.98 eV with a crystallite size of 4.2 nm and a micro stain of 35.42×10 −3 . With a purity of 63.4%, gZ15 demonstrated a significant rate of recombination in the blue region. All of the improved properties demonstrated that polymeric g-C 3 N 4 -ZnS was the optimum materials for usage in the active or emissive layer of optoelectronic devices.