Enhanced Visible‐Light‐Driven Photocatalytic Overall Splitting of Pure Water in a Porous Microreactor

Abstract Photocatalytic overall splitting of pure water (H 2 O) without sacrificial reagent to hydrogen (H 2 ) and oxygen (O 2 ) holds a great potential for achieving carbon neutrality. Herein, by anchoring cobalt sulfide (Co 9 S 8 ) as cocatalyst and cadmium sulfide (CdS) as light absorber to channel wall of a porous polymer microreactor (PP12), continuous violent H 2 and O 2 bubbling productions from photocatalytic overall splitting of pure H 2 O without sacrificial reagent is achieved, with H 2 and O 2 production rates as high as 4.41 and 2.20 mmol h −1 g cat. −1 respectively. These are significantly enhanced than those in the widely used stirred tank‐type reactor in which no O 2 is produced and H 2 production rate is only 0.004 mmol h −1 g cat. −1 . Besides improved charge separation and interaction of H 2 O with photocatalyst in PP12, bonding interaction of Co 9 S 8 with PP12 creates abundant catalytic active sites for simultaneous productions of H 2 and O 2 , thus leading to the significantly enhanced H 2 and O 2 bubbling productions in PP12. This offers a new strategy to enhance photocatalytic overall splitting of pure H 2 O without sacrificial reagent.