CPO-27-Mg　(also　referred　to　as　Mg-2(DOBDC),　DOBDC=2,5-dioxido-1,4-benzenedicarboxylate),　a　Mg2+　based　metal-organic　framework　which　shows　the　highest　CO2　uptake　among　the　already　reported　MOF　materials,　was　chosen　to　combine　with　TiO2　to　form　CPO-27-Mg/TiO2　nanocomposite　via　a　hydrothermal　self-assembly　method.　The　as-obtained　CPO-27-Mg/TiO2　nanocomposite　is　composed　of　TiO2　nanospheres　on　the　spindle-shaped　CPO-27-Mg　microcrystal.　Intimate　contact　between　CPO-27-Mg　and　TiO2　nanospheres　exists　due　to　the　coordination　between　the　carboxylate　groups　in　DOBDC　and　TO4+　in　TiO2.　The　as-obtained　CPO-27-Mg/TiO2　nanocomposite　exhibited　enhanced　performance　for　the　photocatalytic　CO2　reduction　to　form　CO　and　CH4　due　to　its　high　adsorption　capacity　toward　CO2　and　the　existence　of　open　alkaline　metal　sites　in　CPO-27-Mg.　By　incorporating　MOFs　with　open　alkaline　metal　center　into　TiO2,　the　reduction　of　H2O　to　H-2,　a　competitive　reaction　to　photocatalytic　CO2　reduction,　was　totally　inhibited.　This　study　highlights　the　promising　prospect　of　incorporating　MOFs　with　open　alkaline　metal　sites　into　semiconductors　for　artificial　CO2　photo-conversion.　(C)　2015　Elsevier　B.V.　All　rights　reserved.