In this study, WO3/CuMoO4 heterojunction nanocomposites were developed by combining WO3 micro hallow sphere, and CuMoO4 nanoparticles using a hydrothermal method, and were applied as a dual-functional S-scheme photocatalyst for simultaneous degradation of RhB organic pollutants and hydrogen evolution under simulated sunlight irradiation. The findings indicated that such a heterojunction sample exhibited the improved photocatalytic properties, and maximum H2 evolution efficiency of 2.95 g-1 h-1 was achieved for the WO3–40CuMoO4 sample with 40 w/w% of CuMoO4. The enhancement in the photocatalytic activities of these heterojunctions are originated from the reduction in the rate of recombination of the photogenerated charge carriers, enhanced sunlight absorption, and effective generation of reductant (e.g. e for H2 evolution) and oxidant species (such as O2•− and •OH radicals for the dye degradation). The S-scheme charge separation pathway was found to account for the improved photocatalytic properties of the heterojunction samples. In the S-scheme charge mechanism, formation of heterojunction contact between two the WO3 and CuMoO4 semiconductors, facilitates electron transfer between these semiconductors, which leads to improved charge separation, extended lifetimes of electrons and holes, and enhanced photocatalytic efficiency. The synthesized nanocomposite demonstrates satisfactory stability and can be effectively employed as a bifunctional S-scheme photocatalyst for simultaneous degradation of organic pollutants and hydrogen production.