▎ 摘　　要

NOVELTY - Graphene-modified nickel foam matrix growth copper-based composite catalyst comprises hydrotalcite nanosheets grown vertically and staggered on the surface of the nickel foam matrix uniformly coated by reduced graphene oxide (rGO) in the copper-based hydrotalcite/rGO/nickel foam hybrid with hierarchical structure, forming three-dimensional honeycomb-type nanosheet array morphology, after calcination in nitrogen atmosphere, preparing a nanosheet-type array copper-based composite/rGO/foamed nickel catalyst, where the size of the composite nanoplatelets is 50-150 nm, the thickness is 4-15nm, and the size of core-shell copper-copper(I) oxide nanoparticles generated by in-situ self-reduction is 8-40 nm, and uniformly distributing at the junction of adjacent composite nanosheets and rGO/nickel foam matrix. USE - Used as graphene-modified nickel foam matrix growth copper-based composite catalyst. ADVANTAGE - The catalyst: has excellent performance in catalytic reduction of nitro compounds and degradation of organic dyes; is easy to separate; recovers and reuses; and improves the practicability and long-term stability. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for preparing the graphene-modified nickel foam matrix growth copper-based composite catalyst, comprising (1) washing the foamed nickel using acetone, 2 M hydrochloric acid solution, deionized water and absolute ethanol in sequence for 15 minutes, and then vacuum drying at 75-85 degrees C for 170-180 minutes, (2) using modified Hummers method to chemically oxidize 523 mesh natural flake graphite to prepare graphite oxide gel, (3) ultrasonically dispersing the graphite oxide gel (GO, 10 mg/ml) and deionized water prefabricated in step (2) for 15-25 minutes to obtain a completely exfoliated graphite oxide suspension (60 ml in total), then adding citric acid and continuing sonicating for 5-10 minutes to obtain uniform and stable citric acid modified graphite oxide suspension, and transferring it to 100 ml polytetrafluoroethylene-lined autoclave, completely soaking two pieces of 3x 5 cm pretreated clean nickel foam (NF) in the citric acid modified graphite oxide suspension, where the NF piece needs to be slightly bent and vertically clamped into the reactor with the longer side of 5 cm, carrying out hydrothermal treatment at 90-150 degrees C for 4-8 hours, after completing the reaction, naturally cooling to room temperature, repeatedly washing the resulting product using deionized water and ultrasonically washing for 0.5-1 minutes, and freeze drying for 5-8 hours to obtain graphene oxide/NF foamed nickel matrix uniformly coated with graphene oxide, (4) cutting the 2 pieces of 3x 5 cm GO/NF matrix obtained in step (3) into 8 pieces of 1.5x 2.5 cm, placing in a four-necked flask containing 120 ml deionized water, adding 5-30 mg citric acid, under continuous stirring, adding mixed alkali solution dropwise, when the pH of the solution is 10 plus minus 0.1, stopping the addition of the alkali solution, after it is stable for 5-10 minutes, adding 100 ml mixed salt and mixed alkali solution dropwise at the same time to keep the pH value of the solution stable at 10 plus minus 0.1, after the dripping of the mixed salt solution is completed, transferring the resulting slurry containing rGO/NF matrix to the reactor in polytetrafluoroethylene, placing 2 pieces of 1.5x 2.5 cm rGO/NF matrix and 75 ml of above slurry in each 100 ml reactor, crystallizing at 80-120 degrees C for 4-8 hours, after the reaction is over, naturally cooling to room temperature, repeatedly washing the resulting product using deionized water and freeze-drying for 5-8 hours, obtaining the copper-based hydrotalcite/rGO/nickel foam hybrid precursor, denoted as M2+M3+-LDH/rGO/NF, where M2+ and M3+ are divalent and trivalent metal ions, respectively, and (5) placing the product obtained in step (4) in a flowing nitrogen of 50-200 ml/minute, keeping it at 380-600 degrees C for 2-4 hours at a heating rate of 1-5 degrees C/minutes, then naturally cooling to room temperature, and preparing nanosheet-type array copper-based composite/rGO/nickel foam catalyst, which is recorded as copper-copper(I) oxide-M2+M3+(O)/rGO/NF.