The　surface　of　long-term　exposed　building　materials　usually　shows　serious　deterioration　under　continuous　environmental　erosion,　which　can　greatly　shorten　the　service　life　of　building　structures.　The　application　prospect　of　multifunctional　photocatalytic　materials　in　civil　engineering　is　promising　but　the　engineering　application　is　still　limited　due　to　the　inherent　defects　of　traditional　photocatalytic　materials.　In　this　paper,　the　ordinary　Portland　cement　(OPC)　and　alkali　activated　slag　(AAS)　mortar　samples　were　prepared　with　a　photocatalytic　coating　incorporating　novel　core@shell　nanospheres　which　feature　with　TiO2　core　and　CoAl-layered　double　hydroxide　shell　(TiO2@CoAl-LDH).　The　surface　roughness,　microhardness,　contact　angle　and　capillary　water　absorption　of　coated　and　uncoated　mortars　were　analyzed　and　characterized　to　explore　the　effect　of　photocatalytic　coating　on　surface　properties.　The　photocatalytic　activity　and　photo-induced　hydrophilicity　of　the　coated　mortar　were　investigated　by　degrading　methylene　blue　and　contact　angle　tests.　A　simulated　rainwater　washing　test　was　designed　to　evaluate　the　long-term　stability　of　photocatalytic　coatings　on　mortar　substrate.　The　results　show　that　compared　with　unwashed　coated　mortar,　the　coated　mortar　after　rainwater　washing　can　still　maintain　a　higher　photocatalytic　activity,　whereby　the　surface　hydrophilicity　was　increased　with　the　decrease　of　the　surface　roughness　and　capillary　water　absorption.　As　a　newly　developed　protective　coating　material,　TiO2@CoAl-LDH　is　expected　to　confer　multifunctional　properties　to　the　cementitious　materials.　©　2023　Elsevier　Ltd