Preparation method of diatomite loaded graphite carbon nitride composite material photocatalyst

The invention belongs to the technical field of catalysis, and particularly relates to a preparation method of a diatomite loaded graphite carbon nitride composite material photocatalyst. The preparation method comprises the following steps: step A, carrying out hydrothermal reaction on diatom and an aqueous solution containing ammonia nitrogen at 150-200 DEG C for 5-15 hours, cooling to room temperature, carrying out solid-liquid separation, and washing and drying a solid product to obtain nitrogen-containing diatomite; and step B, calcining urea and/or melamine and the nitrogen-containing diatomite obtained in the step A at 500-600 DEG C for 2-6 hours, and cooling to room temperature to obtain the diatomite loaded graphite carbon nitride composite material photocatalyst. According to the method, the characteristics of live diatom ammonia nitrogen solidification and template effect are combined, the efficient and non-toxic green composite photocatalyst is developed, on the premise that ecological animals and