In　the　present　study,　a　simple　method,　involving　precipitation　and　a　subsequent　hydrothermal　synthesis,　was　used　to　prepare　a　supported　gold　catalyst　on　TiO　2　-C　3　N　4　,　which　was　subsequently　evaluated　for　its　performance　for　CO　preferential　oxidation　in　the　presence　of　H　2　.　It　was　found　that　the　supported　gold　catalyst　on　TiO　2　-C　3　N　4　nano-hetero-architecture　had　a　higher　catalytic　activity　than　that　on　the　counterpart　TiO　2　or　C　3　N　4　alone　under　visible　light　irradiation　and　without　visible　light　irradiation.　A　better　contact　between　the　gold　atom　arrangement　and　heterostructured　support　was　clearly　observed　by　transmission　electron　microscopy　(TEM),　which　suggested　as　the　physical　basis　for　highly　efficient　electron　transfer.　Based　on　the　results　of　ex　situ　X-ray　photoelectron　spectroscopy　(XPS),　redox　couple　mode　(TCNE/TCNE　-　)　testing,　transient　photocurrent　and　Fourier　transform-infrared　spectra　(FT-IR)　of　CO　adsorption,　it　was　proposed　that　the　nano-heterostructure　of　TiO　2　-C　3　N　4　and　the　localized　surface　plasmon　resonance　(LSPR)　of　Au　NPs　promoted　electron　transfer　among　the　interfaces　of　TiO　2　,　C　3　N　4　and　Au　NPs,　resulting　in　the　higher　electron　density　of　Au　NPs,　followed　by　the　activation　of　CO　adsorbed　at　the　Au　sites　and　the　formation　of　O　2　-　radical　active　species.　Moreover,　the　re-combination　of　Au-H(ad)　with　the　discharge　of　molecular　hydrogen　induced　by　the　higher　electron　densities　of　Au　NPs　and　the　hydrogen　spillover　of　Au-H(ad)　to　the　support　in　the　formation　of　surface　hydroxyl　groups　could　drive　the　higher　selectivity　of　oxidizing　CO.　In　view　of　its　electronic　effect,　the　nano-heterostructured　TiO　2　/C　3　N　4　hybrid,　which　was　well　attached　to　Au　NPs,　could　lead　to　new　properties　and　could　consequently　promote　CO　preferential　oxidation　in　the　presence　of　H　2　.　©　2016　The　Royal　Society　of　Chemistry.