Crystal facet modulation of BiWO microplates for spatial charge separation and inhibiting reverse reaction.

We experimentally demonstrated that spatial charge separation can take place between the {010} and {001} facets of BiWO microplates. Further assembly of the reduction and oxidation cocatalysts leads to a remarkable enhancement of photocatalytic water oxidation activity in the presence of Fe ions while the reverse oxidation of Fe to Fe ions is totally inhibited. The origin of the driving force is theoretically proven to be the difference in surface work function between the co-exposed facets, which shows a feasible strategy for developing efficient photocatalysts for solar energy conversion.