The invention belongs to the technical field of
photocatalysis, and particularly relates to a preparation method for a visible light ternary photocatalyst. The preparation method comprises the following steps: step 1, adding tetrabutyl
titanate into absolute ethyl
alcohol, and ultrasonically stirring for 30-60 minutes to obtain a
titanate alcohol solution; step 2, slowly dropwise adding ethyl
silicate into the
titanate alcohol solution, mechanically stirring until completely dissolving to obtain a
titanium-
silicon mixed alcohol solution; step 3, adding a dispersing agent into ionized water toform dispersion liquid, and slowly adding the dispersion liquid into
titanium-
silicon alcohol solution to obtain
titanium-
silicon dispersion liquid; step 4, putting
graphene into the titanium-silicondispersion liquid, and performing cyclic ultrasonic reaction for 4-6 hours, thereby obtaining the ternary
mixed solution; step 5, putting the ternary
mixed solution into a decompression
distillation reaction kettle to perform decompression
distillation reaction for 60-90 minutes, thereby obtaining a viscous solution; and step 6, putting the thick solution into a
drying oven to dry for 30-50 minutes, and heating and
sintering for 20-40 minutes, thereby obtaining the ternary photocatalyst. The preparation method solves the problem that performance, in a visible light region, of a
graphene-
titanium dioxide catalyst is not good; and the prepared photocatalyst is high in stability and
photodegradation efficiency.