Charge　transfer　dynamics　is　explored　at　the　interfaces　of　anatase　TiO2　nanowire　(NW)　and　molecules　(H2O　and　NH3)　by　ab　initio　calculations　combined　with　density　matrix　formalism.　H2O　is　partially　dissociated　on　the　surfaces　of　TiO2　NW,　while　NH3　are　molecularly　adsorbed　on　the　surfaces　of　TiO2　NW.　Compared　with　the　bare　NW,　the　H2O　adsorption　increases　the　band　gap　while　NH3　adsorption　decreases　the　band　gap.　Both　the　adsorptions　enhance　the　absorption　strength.　After　the　adsorption　of　NH3,　the　electron　on　the　lowest　unoccupied　orbital　and　the　hole　on　the　highest　occupied　orbital　can　be　efficiently　separated.　For　bare,　H2O　and　NH3　adsorbed　NWs,　the　hole　excited　at　low　energy　deep　in　the　valence　band　takes　longer　time　to　relax　to　the　highest　occupied　orbital,　since　at　higher　excitation　energies,　holes　experience　larger　number　of　subsequent　elementary　relaxation　steps.　The　H2O　and　NH3　adsorptions　greatly　enhance　the　relaxation　rates　of　holes,　which　may　be　due　to　an　additional　coupling　between　the　electronic　states　in　surfaces　of　TiO2　NW　and　vibrational　modes　contributed　by　H2O　or　NH3　and　better　matching　the　resonance　condition　for　such　transitions.　©　2019　American　Chemical　Society.　All　rights　reserved.