▎ 摘　　要

NOVELTY - Producing graphene oxide-carbon nanotube composite, comprises: preparing a first solution by mixing carbon nanotubes, graphite, sodium nitrate, and a solvent; stirring the first solution, and adding potassium permanganate; preparing a second solution by adding distilled water after stirring the first solution to which potassium permanganate is added; heating the second solution; preparing a third solution by adding hydrogen peroxide to the heated second solution; adjusting the pH of the third solution; and preparing a graphene oxide-carbon nanotube composite by ultrasonicating the third solution whose pH is adjusted. USE - The nanotube composite is useful to produce cement paste (claimed). ADVANTAGE - The nanotube composite has excellent dispersibility, mechanical properties, excellent in dispersibility in the cement paste, and minimizes the weight loss of the graphene oxide-carbon nanotube composite due to heat. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for graphene oxide-carbon nanotube composite produced by the above method; and #a cement paste comprising the graphene oxide-carbon nanotube composite, cement, and water.