The BiVO4/WO3 heterojunction exhibited a considerably enhanced light absorption capability compared to pristine forms of WO3 and BiVO4. Typically, the broad peak at 570 nm in the absorption spectrum of the Au/BiVO4/WO3 was attributed to the SPR band of the Au NPs whose size is around 40 nm. These findings suggest that incorporation of Au NPs can extend the light absorption range of the BiVO4/WO3, promoting its ability to utilize a larger portion of the solar spectrum.