For　the　first　time,　CdS　quantum　dots　(QDs)-decorated　InOOH　(CdS-In　for　short)　was　synthesized　by　a　facile　photodeposition　method.　The　experiment　results　showed　that　CdS-In　samples　exhibited　excellent　activity　and　stability　towards　photocatalytic　reduction　of　nitro　aromatics.　The　conversion　ratio　of　4-nitroaniline　(4-NA)　over　CdS-In　sample　that　was　prepared　with　photodeposition　time　of　120　min　(CdS-In-120)　reached　up　to　99.4%　under　visible　light　irradiation　for　40　min,　which　was　even　higher　than　that　achieved　over　commercial　CdS　(86.2%).　Besides　the　significant　enhancement　of　visible　light　absorption,　quantum　sized　CdS　were　decorated　evenly　on　the　surface　of　InOOH,　which　was　very　beneficial　for　the　high　activity.　Furthermore,　the　heterogeneous　junction　formed　at　the　interface　of　CdS　QDs　and　InOOH　can　significantly　increase　the　separation　efficiency　of　photogenerated　charge　carriers.　Active　species　control　experiment　and　electron　spin　resonance　(ESR)　technique　have　proved　that　photogenerated　electrons　are　the　main　active　species　towards　photocatalytic　reduction　of　nitro　aromatics.　It　is　anticipated　that　our　study　would　offer　meaningful　insights　for　exploring　novel　InOOH-based　visible　light　photocatalysts　towards　efficient　reduction　of　nitro　aromatics.　©　2021　Elsevier　Inc.