A major challenge in semiconductor photocatalysis is that unproductive charge recombination at surface defect sites often outcompetes productive charge transfer to reactant molecules. Because synthesis of defect-free structures is likely impossible and certainly impractical, a better strategy is to efficiently leverage defects to do productive work. Our group is working to develop (1) a deeper understanding of defect-mediated energy flow between nanocrystal photocatalysts and molecules, and (2) a new energy funneling scheme that transfers energy from defect sites to acceptor molecules before the energy is lost. If successful, our strategy would transform unwanted defect sites into desirable photochemical reaction centers that could generate reactive intermediates for fine chemical synthesis, photodynamic therapy, and sensing.
