▎ 摘　　要

NOVELTY - Method for preparing transition metal hydroxide-graphene composite material, involves (i) dispersing graphene oxide in deionized water and ultrasonically processing to obtain a graphene oxide dispersion, and (ii) adding transition metal nitrate, trisodium citrate, and hexamethylenetetramine to graphene oxide, heating and freeze-drying to obtain the product. USE - The method is used for preparing the composite material for photocatalytic reduction of carbon dioxide to produce carbon monoxide (all claimed). ADVANTAGE - The method efficiently and selectively reduces carbon dioxide to carbon monoxide, adopts simple and effective operation, and provides a beneficial theoretical and experimental basis for preparing more efficient carbon dioxide reduction materials and reaction systems.