We　report　the　direct　splitting　of　pure　water　by　light-excited　graphitic　carbon　nitride　(g-C3N4)　modified　with　Pt,　PtOx,　and　CoOx　as　redox　cocatalysts,　while　pure　g-C3N4　is　virtually　inactive　for　overall　water　splitting　by　photocatalysis.　The　novelty　is　in　the　selective　creation　of　both　H2　and　O2　cocatalysts　on　surface　active　sites　of　g-C3N4via　photodeposition　triggering　the　splitting　of　water　for　the　simultaneous　evolution　of　H2　and　O2　gases　in　a　stoichiometric　ratio　of　2:1,　irradiated　with　light,　without　using　any　sacrificial　reagents.　The　photocatalyst　was　stable　for　510　hours　of　reaction.　©　2016　The　Royal　Society　of　Chemistry.