A　series　of　N-CQDs/Ag2CO3　composite　crystals　(where　N-CQDs　=　Nitrogen　doped　carbon　quantum　dots)　were　prepared　by　adding　different　volumes　of　a　solution　of　N-CQDs　during　Ag2CO3　crystal　growth.　Under　irradiation　from　a　350-W　Xe　lamp　light　(with　optical　filter,　λ　≥　420　nm),　the　performance　of　N-CQDs/Ag2CO3　in　photocatalytic　degradation　of　phenol　was　evaluated.　The　as-prepared　samples　were　analyzed　by　XRD,　SEM,　TEM,　BET,　element　mapping,　UV-vis　DRS,　FT-IR,　XPS,　transient　photocurrent　response　and　EIS　testing.　The　results　showed　that　after　coupling　with　trace　amounts　of　N-CQDs,　both　the　photocatalytic　activity　and　stability　of　Ag2CO3　were　greatly　boosted.　The　addition　of　N-CQDs　solution　influenced　the　crystallization　of　Ag2CO3,　resulting　in　a　distinct　decrease　in　Ag2CO3　crystal　size　and　an　obvious　increase　in　surface　area.　Moreover,　the　charge　transfer　resistance　was　greatly　reduced,　and　the　separation　efficiency　of　photogenerated　electrons　and　holes　was　strongly　promoted.　The　presence　of　NCQDs　on　the　surface　of　the　catalysts　facilitates　the　transfer　of　photogenerated　electrons,　slowing　the　photocorrosion　rate　of　Ag2CO3,　and　then　resulting　in　higher　stability　than　bare　Ag2CO3　in　degradation.　The　synergistic　effect　of　the　improvement　of　morphology　and　charge　transfer　rate　thus　accounted　for　the　superior　photocatalytic　performance　of　N-CQDs/Ag2CO3.　©　2017　Dalian　Institute　of　Chemical　Physics,　the　Chinese　Academy　of　Sciences