The　photothermal　catalytic　CO2　reduction　has　emerged　as　a　promising　technology　for　the　effective　use　of　solar　energy　and　the　reduction　of　greenhouse　gas　emissions.　MIL-100(Fe),　as　a　MOF　material,　is　always　considered　an　excellent　catalyst　due　to　its　excellent　porous　structure,　low　toxicity,　extraordinarily　high　chemical　stability　and　abundant　active　sites.　However,　the　relationship　between　morphology　and　photothermal　catalytic　CO2　reduction　is　still　being　explored　and　studied.　Here,　we　prepared　the　MIL-100(Fe)　catalysts　with　different　morphologies　of　nanospheres,　nanoparticles　and　bulk　to　investigate　their　photothermal　catalytic　CO2　reduction　performance.　The　results　showed　that　the　nanospherical　sample　exhibited　the　highest　activity　for　photothermal　CO2　reduction　by　H2O　with　CO　productivity　of　124.04　μmol·g-1·h-1　higher　than　the　other　two　samples.　The　characterization　results　and　mechanism　analysis　indicated　that　the　nanospherical　sample　had　a　lower　band　gap　energy　value,　lower　luminescence　intensity　and　stronger　transient　photocurrent　response,　which　effectively　promoted　the　separation　of　photo　generated　electron-hole　pairs.　More　importantly,　the　AQE　calculation　results　indicated　that　the　nanospherical　sample　exhibited　more　lower　activation　energy　in　the　presence　of　both　light　and　heat,　which　is　beneficial　for　photothermal　CO2　catalytic　to　CO.　This　interesting　find　will　provide　experimental　evidence　for　studying　the　morphology　effect　on　photothermal　catalytic　CO2　reduction　process.　©　2025　Elsevier　B.V.