▎ 摘　　要

NOVELTY - A high-sensitivity material for determination of trace formaldehyde in air involves graphene-supported composite powder materials, where the graphene-supported composite powder materials consisting of magnesium oxide, zirconium dioxide, chromic acid and carbon and the preparation method involves adding natural graphite to fuming sulfuric acid, adding oxalic acid with natural graphite, filtering and washing out, adding the filter cake to potassium permanganate concentrated sulfuric acid solution and stirring, adding hydrogen peroxide aqueous solution and washing the filtrate to obtain graphene oxide, dissolving the magnesium salt and the zirconium salt in aqueous solution of hydrochloric acid to form a solution A, dissolving the chromium salt in aqueous solution of citric acid to obtain solution B, adding solution A to solution B, adding composite metal oxide to an aqueous solution of hydrazine hydrate, washing with deionized water and drying to obtain the finished product. USE - High-sensitivity material for determination of trace formaldehyde in air. ADVANTAGE - The material can accurately measure trace formaldehyde in the air without interference from other common coexisting materials. DETAILED DESCRIPTION - A high-sensitivity material for determination of trace formaldehyde in air involves graphene-supported composite powder materials, where the graphene-supported composite powder materials consisting of 8-12 mass% magnesium oxide, 5-8 mass% zirconium dioxide, 7-13 mass% chromic acid and 70-80% carbon and the preparation method involves adding natural graphite to fuming sulfuric acid under continuous stirring, raising the temperature to 45 degrees C and stir for 2-3 hours, slowly adding oxalic acid with the weight of natural graphite, continue to maintaining the temperature for 1 hour, filtering and washing out to neutral, adding the filter cake to a potassium permanganate concentrated sulfuric acid solution with a mass fraction of 15%, heating to 50-55 degrees C and stirring for 2 hours, slowly adding 25 mass% hydrogen peroxide aqueous solution until no bubbles, continue to constant temperature stirring for 1 hour, suction filtration and washing the filtrate to neutrality to obtain graphene oxide, dissolving the magnesium salt and the zirconium salt in a 15-20% aqueous solution of hydrochloric acid to form a solution A, dissolving the chromium salt in a 20-30% aqueous solution of citric acid to form a solution B under continuous stirring, adding the solution A slowly to the solution B, after stirring for 2 hours, raising the temperature to 92-95 degrees C, adding agar powder to stir until completely dissolved and cooling the mixture to room temperature to form a gel, after drying the gel, using the box-type electric resistance furnace and naturally cooling to room temperature to obtain a composite metal oxide composed of magnesium oxide, zirconium dioxide and chromic acid, adding the composite metal oxide to an aqueous solution of hydrazine hydrate having a mass fraction of 15-20% under continuous stirring, adding the graphene oxide to the mixture, raising the temperature to 45 degrees C and stirring at a constant temperature for 4-5 hours, washing three times with deionized water and drying in a vacuum oven at 65 degrees C to obtain a graphene-supported composite powder material composed of magnesium oxide, zirconium dioxide and chromic acid.