Gold　nanoparticles　(GNP)　passivated　by　dithiolated　diethylenetriaminepentaacetic　(DTDTPA)　linkers,　GNP@DTDTPA,　have　been　synthesized.　The　well-defined　ZnO　nanocomposite　(GNP@DTDTPA/ZnO)　functionalized　by　GNP@DTDTPA　was　prepared　via　a　facile　and　green　self-assembly　approach.　The　specific　interaction　mechanism　responsible　for　the　self-assembly　motif　was　elucidated　by　XPS,　zeta　potential　and　FTIR　analysis.　The　self-assembly　process　was　established　primarily　by　a　large　amount　of　polar　functional　groups　such　as　carboxyl　(COOH),　carbonyl　(CO),　and　amide　(NH-CO)　groups　in　the　DTDTPA　profile,　which　impels　GNP@DTDTPA　to　bind　intrinsically　with　hydroxyl　groups　on　the　ZnO　surface　through　hydrogen　bonding　interactions.　On　the　other　hand,　the　attractive　electrostatic　force　between　the　negatively　charged　GNP@DTDTPA　and　the　positively　charged　ZnO　surface　also　contributes　to　the　monodispersivity　of　GNP@DTDTPA　on　the　ZnO　support.　The　GNP/ZnO　obtained　after　calcination　of　GNP@DTDTPA/ZnO　retains　the　mono-distribution　of　GNP　and　exhibits　more　enhanced　photocatalytic　and　photoelectrochemical　performances　compared　to　pure　ZnO.　We　propose　a　possible　mechanism　that　the　well-distributed　GNP　could　serve　as　an　＇electron　reservoir＇　and　improve　the　separation　efficiency　of　photogenerated　electron-hole　pairs.　This　method　could　provide　a　simple　and　straightforward　approach　for　achieving　a　uniform　distribution　of　noble-metal　nanoparticles　on　the　surface　of　semiconductors　for　versatile　photocatalytic　and　photoelectrochemical　applications.　©　2012　The　Royal　Society　of　Chemistry.