▎ 摘　　要

NOVELTY - Preparing nanocatalyst comprises (i) choosing and measuring copper salt, and mixing with sodium citrate and guanosine based on molar ratio of (2-2.5):5:1, and mixing well as mixture, (ii) mixing mixture obtained in step (i) with distilled water, adding 14-15 mg sodium citrate per milliliter of distilled water as ratio, mixing well and using as liquid A, (iii) reacting liquid A obtained in step (ii) at 185-195℃ for at least 80 hours, completing reaction, filtering, washing and drying to obtain precursor Cu-C-pre, and (iv) calcining precursor Cu-C-pre to obtain catalyst Cu/NG-NC. The copper salt comprises hydrated copper nitrate, hydrated copper acetate and/or hydrated copper chloride. USE - The method is useful for preparing nanocatalyst in technical field of electrocatalysis for water treatment (claimed). ADVANTAGE - The method has ≥75% nitrate conversion rate of catalyst under 1.2 V voltage (using silver/silver chloride as reference electrode). The method is economical, simple and suitable for industrial production. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for: use of Cu/NG-NC catalyst in technical field of electrocatalysis for water treatment. preparing electrode by Cu/NG-NC catalyst, comprising (a) measuring Cu/NG-NC catalyst and carbon-based conductive powder in mass ratio of (1-1.5):1, (b) preparing organic solvent as A liquid, (c) adding 1% binder into liquid A to obtain liquid B, (d) adding Cu/NG-NC catalyst and carbon-based conductive powder into liquid B for mixing, adding 2-2.5 mg Cu/NG-NC catalyst per 1 ml liquid B, uniformly mixing and completely dispersing to obtain mixed suspension, (v) uniformly and dropwisely adding mixed suspension on both sides of cathode sheet, and completely evaporating solvent to obtain electrode loaded with Cu/NG-NC catalyst, where the area of control cathode sheet is to loaded with 0.33-1.33 mg of Cu/NG-NC catalyst per 1 cm2.