Hollow polymer dots: nature-mimicking architecture for efficient photocatalytic hydrogen evolution reaction

Mimicking nature is always beneficial for improving the performance of artificial systems. Artificial photosynthesis for hydrogen production is one of the examples, where we can derive significant inspiration from nature. In this study, polymer dots (Pdots) prepared using photoactive polymer PFODTBT and amphiphilic co-polymer under ultra-sonication exhibited a hollow structure mimicking a photosynthetic bacterial, which was highly beneficial for hydrogen evolution. A systematic study of this structure showed that the polymer shell acts as a biological membrane that maintains a slightly higher pH inside the cavity (pH 0.4) compared to the bulk solution. More importantly, a fast proton diffusion across the porous polymer shell was detected. The photocatalytic activity of hollow nanostructure shows 50 times enhancement of initial hydrogen evolution reaction (HER) rate as compared to solid nanoparticles. Further optimization of the photocatalytic performance was achieved by verifying the decrease in Pdots size from 90 nm to 50 nm, showing a significant increase in the photocatalytic performance of the system. This study reveals nature-mimicking hollow Pdots with porous shells as can be a type of promising photocatalysts in the application of solar energy conversion and storage.