Decoration　of　semiconductors　with　plasmonic　nanoparticles　provides　a　new　direction　for　efficient　solar　water　splitting　for　hydrogen　production.　Herein,　Ag　nanoparticles　as　the　plasmonic　metal　were　electrodeposited　on　a　TiO2　nanotube　arrays　(TNTA)　photoelectrode　by　controlling　deposition-charge　density.　The　resulting　Ag/TNTA　electrode　with　10-50　nm　diameter　Ag　nanoparticles　exhibited　a　higher　photocurrent　density　and　hydrogen　production　rate　than　a　bare　TNTA　electrode　under　AM　1.5　irradiation.　The　origins　of　this　enhancement　were　explored　by　analyzing　the　photoelectrochemical　behaviors　with　the　relevant　optical　properties.　The　absorption　of　these　Ag/TNTA　electrodes　in　the　visible　light　region　increased　owing　to　the　surface　plasmon　resonance　(SPR)　effect　of　the　Ag　nano-particles,　and　only　low　photocurrent　densities　under　visible　light　irradiation　were　observed.　The　overall　enhancement　is　owing　to　the　greater　incident　photon-to-electron　conversion　efficiency　in　the　300-400　nm　range　that　is　more　dependent　on　the　interfacial　charge　transfer　from　TNTA　to　Ag　nanoparticles.　The　localized　electronic　field　of　the　SPR　also　reduces　the　electron　transport　time　in　the　Ag/TNTA　electrodes.　(C)　2018　Hydrogen　Energy　Publications　LLC.　Published　by　Elsevier　Ltd.　All　rights　reserved.