Making　full　use　of　low-energy　photons　and　reducing　photogenerated　carriers＇　recombination　rate　have　been　considered　important　ways　to　raise　photoelectrocatalysis　(PEC)　efficiency.　In　this　study,　Ir-doped　ZnO　PEC　electrodes　were　prepared　by　thermal　decomposition　method,　first　principles　calculations　were　used　to　study　the　effects　of　Ir　content　on　the　electronic　structure　and　optical　properties　of　IrxZn1-xO　coatings,　the　PEC　degradation　mechanism　of　the　IrxZn1-xO/Ti　electrodes　was　also　tentatively　presented.　The　results　indicated　that　with　numbers　of　Zn　atoms　replaced　by　Ir　atoms,　impurity　energy　level　appeared　in　ZnO　band　gap,　which　reduced　the　electron　transition　barriers　and　increased　the　number　of　photogenerated　carriers.　Besides,　IrO2　nanoparticles　covered　on　ZnO　nanorods　surface,　acting　as　highly　efficient　electron　transfer　channels　and　electrocatalytic　active　sites,　could　separate　photogenerated　electron-hole　pairs　and　enhance　PEC　performance　effectively.　PEC　performance　of　IrxZn1-xO/Ti　electrodes　with　different　Ir　contents　under　UV　irradiation　was　evaluated　by　rhodamine　B　(RhB)　removal　rate.　Compared　with　pure　ZnO　electrodes,　IrxZn1-xO/Ti　ones　exhibited　much　stronger　degradation　capacity.　Specifically,　Ir0.09375Zn0.90625O/Ti　electrodes　showed　the　highest　degradation　rate　of　99.4　%,　and　a　relatively　high　rate　of　95.2　%　after　working　100　h　continuously,　indicating　its　excellent　long-term　stability.　©　2020　Elsevier　B.V.