The exciton effect is commonly observed in photocatalysts, where substantial exciton binding energy (Eb) significantly hampers the efficient generation of photo-excited electron-hole pairs, thereby severely constraining photocatalysis. Herein, we propose a strategy to reduce Eb through strain-induced charge delocalization. Taking Ta2O5 as a prototype, tensile strain was introduced by engineering a crystalline/amorphous interface, weakening the interaction between Ta 5d and O 2p orbitals, thus endowing a delocalized charge transport and significantly lowering Eb. Consequently, the Eb of strained Ta2O5 nanorods (s-Ta2O5 NRs) was reduced to 24.26 meV, below the ambient thermal energy (26 meV). The ultralow Eb significantly enhanced the yield of free charges, resulting in a twofold increase in carrier lifetime and surface potential. Remarkably, the hydrogen evolution rate of s-Ta2O5 NRs increased 51.5 times compared to commercial Ta2O5. This strategy of strain-induced charge delocalization to significantly reduce Eb offers a promising avenue for developing advanced semiconductor photoconversion systems.

This article is Open Access

Please wait while we load your content... Something went wrong. Try again?