Direct　synthesis　of　urea　from　CO2,　N-2,　and　H2O　through　photocatalysis　stands　out　as　an　effective　solution　to　mitigate　the　over-release　of　CO2　and　alleviate　the　high　costs　associated　with　nitrogen　fertilizer　production.　The　20%　CdS@Bi2WO6　sample　exhibits　optimal　activity　under　visible　light,　achieving　a　urea　yield　of　10.0　mu　molg(-1)h(-1).　The　photocatalytic　efficacy　of　this　composite　is　attributed　to　its　S-type　heterojunction,　which　can　significantly　enhance　the　redox　capacity　and　the　efficiency　of　photogenerated　charge　separation　compared　to　individual　semiconductor　components.　CdS　appears　to　be　responsible　for　the　photocatalytic　reduction　of　N-2　and　urea　synthesis,　while　Bi2WO6　is　involved　in　the　oxidation　of　H2O　to　form　O-2　and　H+.　It　is　suggested　that　urea　is　synthesized　on　the　surface　of　CdS　through　two　mechanisms:　(I)　the　reaction　between　the　activated　intermediates　of　CO2　and　N-2　(mainly)　and　(II)　the　reaction　of　the　in　situ　formed　NH3　with　the　feed　CO2.