0D/1D Heterostructure of Bismuth Molybdate Cluster-Anchored Sodium Titanate Nanotubes for Blue-Light-Driven Photooxidation

Abstract

In this study, we demonstrate the synthesis of 0D/1D Bi₂MoO₆/Na₂Ti₃O₇ (BMT) nanocomposites employing an in situ hydrothermal method for the photocatalytic conversion of benzyl alcohol to benzaldehyde. Various advanced techniques, including X-ray diffraction, transmission electron microscopy, scanning transmission electron microscopy, and a range of spectroscopic methods were employed for structural and morphological analysis of the nanocomposites. The BMT-10 heterostructure, synthesized by loading 10 wt % Bi₂MoO₆ on the surface of Na₂Ti₃O_7, showcases exceptional photocatalytic activity, achieving a conversion rate of 6.8 mmol_{converted BzOH} g_cat^–1 h^–1. This rate surpasses most reported values and is comparable to the best-performing catalytic systems for the selective photooxidation of benzyl alcohol driven by blue LED irradiation (450 nm < λ < 495 nm). The extraordinary performance results from the elevated charge separation and an effective inhibition in charge recombination rates, facilitated by the synergistic effect of the BMT-10 heterostructure. Active intermediate trapping experiments confirm that·O₂^–,·OH, and h⁺ radicals are the primary reactive species responsible for the improved activity, adopting a Z-scheme charge dynamics approach. In addition, the XPS results show that benzyl alcohol exhibits a large adsorption affinity for BMT-10, whereas benzaldehyde shows a weak affinity, which aids the conversion of the reactants. After five consecutive cycles, the photocatalytic activity of the BMT-10 heterostructure remained unchanged, indicating excellent stability during repeated use. This work presents a facile and effective method for optimizing the photocatalytic selective oxidation of benzyl alcohol to benzaldehyde, offering significant potential for sustainable chemical synthesis.