The　location　and　nature　of　the　doped　elements　strongly　affect　the　structural,　electronic　and　optical　properties　of　TiO2.　To　tailor　the　band　structure　and　modify　the　photoelectrochemical　properties　of　TiO2,　a　pair　of　dopants　is　selected.　Fe　and　N　atoms　are　inserted　in　the　TiO2　network　at　substitutional　and　interstitial　sites　with　different　relative　distances.　The　main　objective　behind　the　different　locations　and　sites　of　the　doped　elements　is　to　banish　the　isolated　unoccupied　states　from　the　forbidden　region　that　normally　annihilates　the　photogenerated　carriers.　Fe　at　the　Ti　site　and　N　at　the　O　site　doped　in　the　TiO2　network　separated　at　a　distance　of　7.805　Å　provided　a　suitable　configuration　of　dopant　atoms　in　terms　of　geometry　and　band　structure.　Moreover,　the　optical　properties　showed　a　notable　shift　to　the　visible　regime.　Individual　dopants　either　introduced　isolated　unoccupied　states　in　the　band　gap　or　disturbed　the　fermi　level　and　structural　properties.　Furthermore,　the　other　co-doped　configurations　showed　no　remarkable　band　shift,　as　well　as　exhibiting　a　suitable　band　structure.　Resultantly,　comparing　the　band　structure　and　optical　properties,　it　is　argued　that　Fe　(at　Ti)　and　N　(at　O)　doped　at　a　distance　of　7.805　Å　would　strongly　improve　the　photoelectrochemical　properties　of　TiO2.　©　2018　by　the　authors.