▎ 摘　　要

NOVELTY - Catalyst is formed of graphene oxide coated nanoparticles with a particle size of less than 100 nm. USE - The catalyst is useful for removing formaldehyde in waste water (claimed). ADVANTAGE - The catalyst uses nano-particles with a particle size of less than 100 nm to improve the dispersibility of graphene oxide in wastewater, ensures to be uniformly disperse in the reaction system without sedimentation to fully contact with the formaldehyde and hydrogen peroxide in the wastewater to efficiently remove the formaldehyde, and uses graphene oxide to improve the oxidation ability of hydrogen peroxide and avoid the ineffective decomposition of hydrogen peroxide. The method avoids the environmental problems caused by using inorganic acid or alkali as catalyst, and is environmentally-friendly, safe and non-toxic process. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following: (1) a method for preparing the catalyst for removing formaldehyde in wastewater, involving adding nanoparticles with a particle size of less than 100 nm to graphene oxide solution under stirring, and vacuumizing until there is no liquid; and (2) a method for removing formaldehyde in wastewater using the catalyst, involving adding hydrogen peroxide solution and catalyst to wastewater containing formaldehyde in sequence, and stirring and reacting at 25-75 degrees C for 2-24 hours.