Polymeric carbon nitride (PCN) is a promising hotspot metal-free material for artificial photosynthesis, solar energy conversion, and photo degradation of pollutant, hence predicting unsatisfactory photocatalytic efficiency due to fast charge recombination. Here, we implemented a remediation approach to fuel its catalytic performance by interpretation of a sulfur rich-material, ie, trithiocyanuric acid (TTCA) in the framework of PCN by traditional one facile protocol called copolymerization (molecular assembled) under nitrogen at 550 degrees C. Results demonstrate that the integration of TTCA comonomer into the triazine oligomers of PCN widens the specific surface area, extends the lifetime of photoexcited charge carriers, speeds up the rate of photogenerated electrons optimized from lower energy state toward high energy state, lowers the rate of charge recombination and band gap, and modulates its electronic structure and optical properties in a regular fashion as compared with pristine PCN. Ultimately, due to aforementioned modification, the copolymerized PCN semiconductor predicts superior photocatalytic properties of hydrogen energy production about 7 times higher than that of pristine PCN from the water splitting system.