Plasmon enhanced quantum dots fluorescence and energy conversion in water splitting using shell-isolated nanoparticles

Optically tunable quantum dots (QDs) have drawn significant attention for optoelectronic applications such as light-emitting diodes, photovoltaics, and photodetectors. However, when QDs are assembled as films, the quantum yield decreases significantly, known as the “self-quenching” effect. In this study, we develop a general method for suppressing this self-quenching effect and enhancing energy conversion efficiency using shell-isolated nanoparticles (SHINs), which efficiently promote spontaneous emission of diverse QD films to picosecond timescale. We discover that Ag SHINs with controllable thickness shells exhibit different enhancement factors due to the competition between radiative and non-radiative decay, and localized surface plasmon resonance (LSPR) in nanocavities enhances the fluorescence of QD monolayer films up to nearly 1000 times by SHINs with 6 nm shell. In addition, acting as nanoantennas and amplifying the local photon density, SHINs also effectively enhance excitons excitation and improve the H₂ evolution performance of QD-PEC to nearly 12 µmol/h in neutral solution without “hot” electrons effect.