The　efficiency　of　photocatalytic　reduction　of　CO2　with　water　to　hydrocarbons　is　largely　limited　by　high　recombination　rate　of　photogenerated　electrons　and　holes　in　the　photocatalysts.　Herein,　0D/2D　CeO2/LaTiO2N　S-scheme　heterojunction　photocatalyst　prepared　by　simple　in-situ　hydrothermal　approach　realizes　the　overall　conversion　of　gaseous　CO2　and　H2O　without　any　sacrificial　reagent　and　cocatalyst.　The　yields　of　CH4　and　CO　over　CeO2/LaTiO2N　sample　under　visible　light　for　3　h　are　1.5　and　7.2　μmol　g−1,　and　the　corresponding　utilized　photoelectron　number　(UPN)　is　26.4　μmol　g−1,　about　7.3　and　7.8　times　that　of　individual　LaTiO2N　and　CeO2,　respectively.　The　enhanced　photocatalytic　activity　of　0D/2D　CeO2/LaTiO2N　is　attributed　to　the　constitution　of　the　S-scheme　heterojunction,　which　effectively　inhibits　the　recombination　of　photogenerated　carriers.　This　study　is　expected　to　provide　a　new　insight　into　the　construction　of　efficient　0D/2D　photocatalysts　for　visible-light-driven　photocatalytic　CO2　reduction.　©　2022　Wiley-VCH　GmbH.