Plasmonic Mo-doped HNb3O8 nanosheets with tunable energy band structures for photothermal catalytic H2 evolution in the full solar spectrum†

Abstract

Ultrathin Mo-HNb₃O₈ nanosheets were synthesized by a facile hydrothermal process. Introducing low-valence Mo and oxygen vacancies into the pristine HNb₃O₈ nanosheets can modulate the band structure and induce the localized surface plasmon resonance (LSPR) to increase the charge-carrier densities and produce hot carriers derived from the non-radiative decay of LSPR, which not only efficiently promotes the separation and transfer of photo-generated carriers, but also improves the high utilization rate of solar energy in photothermal catalytic hydrogen evolution in the full solar spectrum. The optimized MoNb-10 exhibits the highest H₂ evolution rate (220.4 μmol h⁻¹ g⁻¹), which is approximately 7.7 times higher than that of the HNb₃O₈ nanosheet. The current work not only deepens our understanding of LSPR effects generated from the Mo dopant and OVs on the surface of transition metal oxide nanosheets, but also provides clues for exploring new photothermal catalysts to promote future solar energy conversion.