Solar-driven molecular oxygen activation by semiconductor photocatalysts is a prototypical reaction manifesting complex interactions among photons, charge carriers, and reactants. In this study, we demonstrate that energetic O2 activation towards volatile organic compound control can be realized via constructing a sophisticated surface hydrogen bond (HB) network having a dual-function. The extensive HBs established between the hydroxyl-rich BiOCl surface and phosphoric acid are first shown to significantly weaken surface Bi-O bonds, enabling fa...