Conversion　of　carbon　dioxide　into　useful　chemicals　has　attracted　great　attention.　However,　the　significant　bottlenecks　facing　in　the　field　are　the　poor　conversion　efficiency　of　CO2　and　low　selectivity　of　products.　Herein,　hierarchical　BiOBr　hollow　microspheres　are　fabricated　by　a　solvothermal　method　using　ethylene　glycol　(EG)　as　solvent　in　presence　of　polyvinyl　pyrrolidone　(PVP).　The　hollow　BiOBr　microspheres　prepared　at　120　degrees　C　exhibit　the　best　performance　for　CO2　photoreduction.　The　evolution　rates　of　product　CO　and　CH4　are　up　to　88.1　mmol　g(-1)h(-1)　and　5.8　mmol　g(-1)h(-1),　which　are　8.8　times　and　5.8　times　higher　than　that　of　plate-like　BiOBr　respectively.　The　hollow　microspheres　possess　larger　specific　area　and　generate　multiple　reflections　of　light　in　the　cavity,　thus　enhancing　the　utilization　efficiency　of　light.　The　modulated　electronic　structure　by　oxygen　vacancy　(OVs)　is　beneficial　to　the　transfer　of　photogenerated　electrons　and　holes.　Especially,　the　enriched　charge　density　of　BiOBr　by　OVs　is　conductive　to　the　adsorption　and　activation　of　CO2,　which　could　lower　the　overall　activation　energy　barrier　of　CO2　photoreduction.　In　summary,　the　synergistic　effect　of　the　hollow　structure　with　OVs　plays　a　vital　role　in　boosting　the　photoreduction　of　CO2　for　BiOBr.　This　work　provides　a　new　opportunity　for　designing　the　high　efficiency　catalyst　by　morphology　engineering　with　defects　at　the　atomic　level　for　CO2　photoreduction.　(C)　2021　Elsevier　Inc.　All　rights　reserved.