Facile Ball-Milling Strategy for Constructing Covalently Connected Black Phosphorus–MoO3–x Heterostructures for Enhanced Photocatalytic Hydrogen Evolution

Photocatalytic water splitting to produce hydrogen is considered to be a promising approach to clean, sustainable, and renewable energy. The highly efficient photocatalysts play a key role in photocatalytic hydrogen production. Owing to its high charge carrier mobility and tunable band gap, black phosphorus (BP) has emerged as a potential photocatalyst. However, when using BP for photocatalytic hydrogen production individually, the inherent instability and light-harvesting capability greatly restricted the further application, as well as the fast photogenerated electron–hole recombination. Herein, a novel heterostructured photocatalyst BP-MoO3–x was prepared via the direct ball-milling method for H2 photogeneration. The result demonstrated that coupling BP with the localized surface plasmonic defective MoO3–x through covalent Mo–P bond improves the chemical stability, enables the visible-to-near infrared photons to harvest, and promotes the photogenerated carrier separation. As a result, the BP-MoO3–x could deliver high photocatalytic hydrogen production rates of 396.3 and 156.4 μmol·g–1·h–1 under visible and near-infrared lights, which are ∼40 and 80 times higher than that of BP without any sacrificial agent, respectively. Furthermore, the BP-MoO3–x also shows good stability under visible light irradiation from cycle stability testing. Combining with density functional theory (DFT) calculations, the synergistic effect of Z-scheme BP-MoO3–x heterostructure and strong localized surface plasmon resonance (LSPR) enhances light-harvesting capacity and improves the photoexcited charge transfer efficiency.