The　Fe-0/C3N4/MoS2　heterostructure　was　fabricated　through　photochemical　synthesis　that　was　free　of　NaBH4.　Specifically,　the　g-C3N4/MoS2　(GCNM)　composite　was　used　as　the　substrate.　Visible　light　excited　the　electrons　from　the　valence　band　of　the　GCNM　in　the　substrate,　and　the　excited　electrons　reduced　the　Fe2+　ions　in　the　solution　nearby　GCNM　to　Fe-0　and　then　created　the　Fe-0/C3N4/MoS2　heterostructure.　Small　Fe-0　(＜9　nm)　dots　well　dispersed　on　the　GCNM　surface　were　obtained,　because　the　diffusion　of　the　Fe　ions　in　the　solution　and　the　diffusion　of　the　electrons　on　the　GCNM　substrate　restricted　the　growth　of　Fe-0　nanoparticles.　The　smaller　size　of　Fe-0　provided　a　larger　number　of　active　metal　centers　and　improved　the　carrier　separation　efficiency.　As　a　result,　the　Fe-0/C3N4/MoS2　heterostructure　exhibited　superior　catalytic　properties　in　the　redox　reactions　of　rhodamine　B,　Cr(VI),　Pb(II),　and　Cd(II).　It　could　also　be　readily　recycled　without　severe　loss　of　catalytic　performance.　(C)　2017　Published　by　Elsevier　B.V.