Hierarchically Periodic Macroporous Niobium Oxide Architecture for Enhanced Hydrogen Evolution.

The fabrication of periodic macroporous (PM) in NbO via morphological control is crucial for improving the photocatalytic hydrogen evolution efficiency. In this study, NbO with PM is synthesized using a straightforward colloidal crystal templating approach. This material features an open, interconnected macroporous architecture with nanoscale walls, high crystallinity, and substantial porosity. Extensive characterization reveals that this hierarchically structured NbO possesses abundant surface active sites and is capable of capturing light effectively, facilitating rapid mass transfer and diffusion of reactants and markedly suppressing the recombination of photoexcited charge carriers. Macroporous NbO exhibits superior water-splitting hydrogen evolution performance compared with its bulk and commercial counterparts, achieving a hydrogen production rate of 405 µmol g h, surpassing that of bulk NbO (B-NbO) and commercial NbO (C-NbO) by factors of 5 and 33, respectively. This study proposes an innovative strategy for the design of hierarchically structured PM, thereby significantly advancing the hydrogen evolution potential of NbO.