Photocatalytic　overall　water　splitting　represents　a　promising　strategy　for　sustainable　hydrogen　production.　However,　photocorrosion　and　dissolution　of　photocatalysts　and　cocatalysts　are　common　concern　for　the　solid-liquid　phase　reaction.　Recently,　the　above　issues　could　be　addressed　by　Domen　and　coworkers,　when　the　photocatalytic　water　splitting　was　conducted　in　the　presence　of　water　vapor,　which　dramatically　restrain　the　undesired　corrosion　of　the　photocatalysts　and　cocatalysts.　Besides,　surface　decoration　of　hygroscopic　TiOx　layer　promotes　adsorption　of　water　molecules　and　prevents　the　corrosion　process.　In　addition,　vapor-fed　photocatalytic　water　splitting　remains　considerable　apparent　quantum　yield　compared　with　the　liquid　water　photocatalytic　overall　water　splitting　at　pressurized　condition,　which　endows　great　potential　in　practical　application.