Electrocatalytic　carbon　dioxide　reduction　reaction　(CO2RR)　is　a　promising　strategy　to　mitigate　the　greenhouse　gas　effect.　The　implementation　of　such　a　technique　highly　depends　on　efficient　electrocatalysts.　Here,　we　report　a　composite　catalyst　of　Ag@BIF-73NSs,　prepared　by　loading　Ag　nanoparticles　on　boron　imidazolate　framework　(BIF)　nanosheets　(BIF-73NSs)　through　the　hydroxyl　functional　group　of　the　organic　ligand　in　BIF-73NSs,　as　an　electrocatalyst　for　electroreduction　of　CO2　to　CO.　In　the　obtained　Ag@BIF-73NSs　catalysts,　ultrasmall　Ag　nanoparticles　(∼2　nm)　were　evenly　dispersed　on　the　ultrathin　2D　BIF-73　nanosheets　with　a　thickness　of　∼2　nm.　Electrocatalytic　results　clearly　demonstrated　that　Ag@BIF-73NSs　exhibits　much　higher　performance　for　electrocatalytic　reduction　of　CO2　to　CO　with　a　FE　close　to　90%,　which　is　comparable　to　those　of　pure　Ag,　but　comparatively　at　much　lower　Ag　loading　(Ag,　3.39　wt%).　Moreover,　the　mass　current　density　of　Ag@BIF-73NSs　(1816.67　A　cm−2　g−1　Ag,　ICP-AES　3.39　wt%　Ag)　is　1101-fold　higher　than　that　of　Ag@graphene　(1.65　A　cm−2　g−1　Ag,　ICP-AES　57.13　wt%　Ag)　sheet　composites.　These　results　indicate　that　Ag@BIF-73NSs　achieves　highly　selective　CO　generation　with　low　metal　Ag　loading　in　electrochemical　CO2RR　catalysis　by　evenly　loading　Ag　nanoparticles　on　ultrathin　boron　imidazolate　framework　nanosheets　through　coordination　effects.　©　2023　The　Royal　Society　of　Chemistry.