▎ 摘　　要

NOVELTY - Preparing graphene powder by hydrothermal reduction comprises (i) using modified Hummers method to prepare graphene oxide, (ii) adding the graphene oxide into water, and performing ultrasonic dispersion treatment to obtain graphene oxide dispersion liquid, (iii) dropping nitric acid and/or nitrate solution into graphene oxide dispersion liquid, performing ultrasonic dispersion treatment, and stirring uniformly to obtain mixed dispersion liquid, (iv) adding the mixed dispersion in the reaction kettle, performing hydrothermal reduction reaction to obtain dispersion liquid containing graphene, and (v) washing the graphene-containing dispersion with water, and drying to obtain graphene powder. USE - The method is useful for preparing graphene powder by hydrothermal reduction. ADVANTAGE - The method performs hydrothermal reduction by nitrate auxiliary effect, and promotes reduction of graphene oxide in the process of graphene oxide layer. The reduced product graphene does not agglomerate.