Photoelectrocatalysis　is　effective　for　the　oxidation　of　ammonium　(NH4+)　due　to　the　ability　to　produce　oxidizing　species　such　as　•OH　and　Cl•.　Compared　to　•OH　and　Cl•,　ClO•　is　a　more　robust　species　capable　of　oxidizing　NH4+,　which　can　be　produced　by　the　combination　of　•OH　and　Cl•　with　free　chlorine.　However,　the　conventional　photoelectrochemical　(PEC)　systems　generally　prefer　to　produce　Cl•　for　NH4+　oxidation　due　to　the　lack　of　sufficient　HOCl.　Herein,　a　UV-driven　PEC　system　consisting　of　TiO2/Ru-IrO2　bifacial　electrode　has　been　constructed　for　the　enhanced　ClO•　generation　for　NH4+　oxidation.　Large　amounts　of　HOCl　can　be　generated　at　the　Ru-IrO2　interface,　which　can　be　further　activated　by　UV　irradiation　to　generate　Cl•　and　•OH,　and　then　rapidly　react　with　HOCl　to　generate　ClO•.　The　Cl•　and　•OH　generated　at　the　TiO2　interface　could　also　react　with　HOCl,　further　accelerating　the　generation　of　ClO•.　Under　UV　irradiation,　the　oxidation　rate　of　TiO2/Ru-IrO2　was　6.7　times　than　TiO2,　1.5　times　than　Ru-IrO2,　and　even　1.24　times　than　the　sum　of　individual　TiO2　and　Ru-IrO2.　In　addition,　the　bifacial　electrode　achieved　highly　efficient　NH4+　oxidation　for　the　treatment　of　actual　wastewater,　eliminating　81.0　mg　L−1　of　NH4+　in　120　min　with　a　TN　removal　rate　of　98.4%.　The　UV-driven　PEC　system　with　TiO2/Ru-IrO2　bifacial　electrode　is　a　promising　potential　technology　for　NH4+　oxidation　due　to　its　ability　to　rapidly　produce　ClO•　and　oxidize　NH4+　to　N2　without　the　addition　of　chemical　reagents.　©　2023　Elsevier　B.V.