Two　series　of　lanthanide-carboxylates,　[Ln(2,2′-dtba)(2,2′-Hdtba)(EtOH)]n　(I:Ln=Eu(1a),　Dy(1b))　and　[Ln(2,2′-dtba)(2,2′-Hdtba)(4,4′-bpy)0.5]n　(II:Ln=Eu(2a),　Dy(2b),　Tb(2c)　2,2′-H2dtba=2,2′-dithiodibenzoic　acid,　4,4′-bpy=4,4′-bipyridine)　have　been　synthesized　under　hydrothermal　conditions.　Interestingly,　the　H2dtba　organic　ligand　was　generated　by　in　situ　S–S　reaction　of　2-mercaptobenzoic　acid.　Compounds　I　and　II　possess　different　2D　layered　structures　based　on　similar　1D　[Ln(2,2′-dtba)]+　chains.　Photoluminescence　studies　reveal　that　compounds　I　and　II　exhibit　strong　lanthanide　characteristic　emission　bands.　Remarkably,　Compounds　1b　and　2a　both　exhibit　good　photocatalytic　activity　for　degradation　of　Rhodamine-B　(Rh-B)　under　the　simulated　sunlight　irradiation.　©　2016　Elsevier　Inc.