Employing　upconversion　hosts　(which　convert　lower-energy　light　into　higher-energy　light)　and　plasmonic　Au　nanoparticles,　this　work　deals　with　the　synthesis　of　a　novel　Au/NaYF4:Yb,Er/WO3·0.33H2O-W18O49　{denoted　as　A/NYYE/WW}　heterojunction　via　a　hydrothermal　method　followed　by　a　photo-reduction　method.　Also,　A/NYYE/WW　exhibited　the　optimum　photocatalytic　activity　and　stronger　photocatalytic　stability　for　the　degradation　of　nitrobenzene　aqueous　solution　in　comparison　with　a　single　WO3·0.33H2O　or　NYYE/WW　component.　Based　on　the　results　of　X-ray　diffraction　patterns,　field　emission　electron　microscopy,　X-ray　photoelectron　spectra,　UV-Vis　diffuse　reflectance　spectra,　upconversion　luminescence　spectra,　luminescence　decay　and　photoelectrochemical　measurements,　it　could　be　considered　that　a　Z-scheme　heterojunction　was　generated　over　A/NYYE/WW,　in　which　a　highly　efficient　Förster　resonant　energy　transfer　from　NYYE　to　WO3·0.33H2O-W18O49　was　observed　and　the　localized　surface　plasmon　resonance　(LSPR)　effects　of　Au　NPs　and　W18O49　could　induce　the　utilization　of　near　infrared　light　to　achieve　broadband　light　absorption.　On　the　other　hand,　Au　NPs　also　played　the　role　of　an　electron　sink　for　enhanced　charge　carrier　separation　and　utilization.　Thus,　the　heterojunction　showed　the　synergetic　effects　of　both　upconversion　and　LSPR　features,　which　could　broaden　the　absorption　spectrum　to　the　near　infrared　region　and　give　rise　to　a　higher　yield.　It　provides　a　pathway　to　develop　broadband　absorption　materials　in　photocatalytic　systems.　©　2019　the　Partner　Organisations.