The invention belongs to the technical field of photo-catalysts and composite adsorbing materials and in particular relates to selective composite photo-catalyst
powder and a preparation method and application thereof. The
chemical formula of the composite photo-catalyst
powder is La2NiO4 / Y2Mo4O15. The preparation method comprises the following steps: weighing soluble salts of
nickel and soluble salts of
lanthanum according to a
molar ratio of 1 to 2, dissolving the salts in
distilled water, thereby obtaining a solution A; slowly adding a
sodium hydroxide solution, stirring, performing suction
filtration on the solution, thereby obtaining a precipitate B; calcining and maintaining the temperature in a
muffle furnace, thereby obtaining catalyst
powder C; adding the powder C into an alcoholic solution, performing ball milling at high speed, thereby obtaining powder D (La2NiO4); weighing a proper amount of soluble salts of
yttrium, measuring a certain amount of
ammonium molybdate, dissolving in a proper amount of
distilled water, thereby obtaining a solution E; and mixing the solution E and the powder D,
drying, calcining, thereby obtaining the composite catalyst powder. The composite photo-catalyst powder can be used in degradation treatment of insoluble organic matters in industrial
wastewater and particularly has an obvious
catalytic degradation effect on
methylene blue.