Low-temperature synthesis of hierarchical flower-like hexagonal molybdenum trioxide films on wood surfaces and their light-driven molecular responses

Hierarchical flower-like hexagonal molybdenum trioxide (MoO₃) film, with a light-driven response, was grown on a wood surface using a one-pot low-temperature hydrothermal method. The crystal structures, microstructure investigations, chemical compositions, and UV–Vis analysis of the MoO₃ film on the wood surface were studied. In addition, the growth mechanism of the flower-like MoO₃ was put forward. The X-ray diffraction results show that the fabricated MoO₃ had a hexagonal structure and the average grain size was 65.6 nm, according to Scherrer’s equation. Scanning electron microscopy analysis demonstrated that the hierarchical MoO₃ film was composed of many unique bumps that were assembled using numerous microrods. The formation mechanism reveals that during the hydrothermal process the dispersive MoO₃ particles first created and then assembled the 3D flower-like structures. The energy dispersive spectrometer, Raman spectrum, and X-ray photoelectron spectroscopy confirmed the MoO₃ film grown on the wood surface. The UV–Vis analysis suggested that the as-fabricated product responded well to stimulation from a UV light at 365 nm and exhibited outstanding color changes. The calculated band gap of the MoO₃ film based on K–M model was around 2.98 eV.