M/Ag3PO4　(M　=　Pt,　Pd,　Au)　Schottky-type　heterostructures　were　successfully　fabricated　by　a　chemical　deposition　route　using　NaBH4　as　a　reduction　agent.　The　structure　and　optical　properties　of　the　as-synthesized　samples　were　characterized　by　X-ray　diffraction,　scanning　electron　microscopy,　transmission　electron　microscopy,　X-ray　photoelectron　spectroscopy,　UV-vis　diffuse　reflectance　spectroscopy,　and　electrochemical　techniques.　The　photocatalytic　activity　was　evaluated　by　the　decomposition　of　dyes　(methyl　orange,　methylene　blue,　and　rhodamine　B)　under　visible　light　irradiation　(lambda　＞　420　nm).　These　noble　metals　as　nanoparticles　were　highly　dispersed　on　the　surface　of　Ag3PO4　polyhedrons.　The　light　absorption　of　Ag3PO4　in　both　the　UV　and　visible　regions　was　extensively　increased　upon　noble　metal　deposition.　The　photocurrent　response　over　M/Ag3PO4　electrodes　was　much　higher　than　that　of　pure　Ag3PO4　and　followed　the　decreased　order　of　Pt　＞　Pd　＞　Au.　The　metallic　nanoparticles　deposited　on　Ag3PO4　could　promote　the　transfer　of　photo-generated　electrons,　which　not　only　inhibited　the　recombination　of　electrons　and　holes　effectively,　but　also　suppressed　the　photocorrosion　of　Ag3PO4,　leading　to　a　significant　increase　in　photocatalytic　activity　and　stability.　On　the　basis　of　radical-trapping　experiments　and　the　PL　technique,　h(+)　and　O-center　dot(2)-　were　well-established　to　correspond　to　the　quick　photo-degradation　of　dyes　and　a　possible　mechanism　was　proposed.