The　bifunctional　photocatalyst　Pt/TiO2-xNx　has　been　successfully　prepared　by　wet　impregnation.　The　properties　of　Pt/TiO2-xNx　have　been　investigated　by　diffuse　reflectance　spectra,　X-ray　diffraction,　transmission　electron　microscopy,　X-ray　photoelectron　spectroscopy,　a　photoluminescence　technique　with　terephthalic　acid,　and　electric　field　induced　surface　photovoltage　spectra.　The　photocatalytic　activity　of　the　sample　was　evaluated　by　the　decomposition　of　volatile　organic　pollutants　(VOCs)　in　a　H-2-O-2　atmosphere　under　visible　light　irradiation.　The　results　demonstrated　that　nitrogen-doped　and　platinum-modified　TiO2　in　a　H-2-O-2　atmosphere　could　enormously　increase　the　quantum　efficiency　of　the　photocatalytic　system　with　excellent　photocatalytic　activity　and　high　catalytic　stability.　The　increased　quantum　efficiency　can　be　explained　by　enhanced　separation　efficiency　of　photogenerated　electron-hole　pairs,　higher　interface　electron　transfer　rate,　and　an　increased　number　of　surface　hydroxyl　radicals　in　the　photocatalytic　process.　A　mechanism　was　proposed　to　elucidate　the　degradation　of　VOCs　over　Pt/TiO2-xNx　in　a　H-2-O-2　atmosphere　under　visible　light　irradiation.