Photocatalytic coatings are capable of achieving pollution-free degradation of organic pollutants on the surface of buildings. The preparation of photocatalytic coatings with high degradation efficiency, stability and durability constitutes a significant challenge in current widespread applications. This study prepared g-C3N4/MoS2 photocatalytic materials through a simple hydrothermal combined low-temperature calcination process, and selected the materials through characterization and photocatalytic degradation of organic wastewater experiments. Finally, poly(dimethylsiloxane) (PDMS) was added to obtain a g-C3N4/MoS2@PDMS coating. The coating was applied to the concrete surface, and, in the experiment, the coating showed good durability, stability, and high photocatalytic activity.