Quantum Well Superlattice Heteronanostructures for Efficient Photocatalytic Hydrogen Evolution.

Abstract

In this study, we construct a quantum well effect-based two-dimensional Z-scheme superlattice heteronanostructure photocatalyst constructed from hydrogen-bonded porphyrin organic frameworks (HOFs) and carbon nitride. Porphyrin HOFs extend spectral absorption, while their π-conjugation and electron density variations significantly enhance charge separation and exhibit favorable alignment with the energy levels of carbon nitride, thereby enabling efficient charge transfer. Carboxylic acid channels in the HOFs further promote the decomposition of water molecules, thereby boosting hydrogen production. Experimental results indicate an improvement in carrier separation efficiency from 6.97 to 50.31%, resulting in a 935-fold increase in the hydrogen evolution rate of 187.2 mmol/g/h. Such a rate represents the highest performance among the currently reported porphyrin-based and carbon-based photocatalysts. This work highlights the potential of quantum well-based heterostructure design in optimizing photocarrier dynamics, providing a promising strategy for advancing photocatalytic hydrogen evolution.