Hydrogen　production　over　dye-sensitized　Pt/P25　under　visible-light　irradiation　was　investigated　by　using　methanol　or　TEOA　as　an　electron　donor.　Ru2(bpy)(4)L-1　-　PF6　shows　the　best　photosensitization　due　to　its　largest　conjugation　system,　widest　range　of　visible-light　and　＇antenna　effect＇　among　the　used　three　Ru(II)-bipyridyl　dyes.　Ru2(bpy)(4)L-1　-　PF6　loosely　linked　with　TiO2　also　exhibit　more　steady　and　higher　increases　in　H-2　evolution　upon　prolonging　the　irradiation　time　than　the　tightly　linked　N719.　The　dynamic　equilibrium　between　the　linkage　of　ground　dye　and　divorce　of　oxidized　dye　from　TiO2　can　enhance　the　electron-injection　and　hinder　the　backward　transfer,　and　then　improve　the　H-2　evolution　efficiency.　(C)　2008　Elsevier　B.V.　All　rights　reserved.