Laser induced crystal formation of layered molybdenum trioxide

Abstract Layered transition metal oxides (TMOs) have been utilized for centuries due to their abundance and diverse applications across various fields. Developing efficient synthesis methods of layered TMOs is crucial for exploring novel properties and potential applications. This work introduces Laser Induced Molybdenum trioxide (LIM), a direct laser synthesis method for producing transition metal oxides and crystals. We outline the laser synthesis protocol for successfully synthesizing layered transition metal oxides using alpha molybdenum trioxide as a representative example. Compared to state-of-the-art (SOTA) techniques, such as hydrothermal, spray pyrolysis, and others, the direct laser process is simple, requiring only a 450 nm monochromatic blue laser light source and minimal handling, and it is also scalable (1 g/3 h of α-MoO ₃ crystals). Additionally, it consumes just 0.108 kWh of energy per gram of α-MoO ₃ , which achieves performance improvements exceeding 100-fold compared to SOTA methods. It produces long crystals with a length of up to 400 μm, comparable to arduous chemical and physical vapor deposition methods. The application prospects of MoO ₃ crystals were demonstrated by integrating them into a polymer matrix as optical band rejection filters for selective ultraviolet light (UV) filtering in the 200–220 nm range. Two filters configurations, flat disc and optical fiber-based filters were fabricated using different concentrations of MoO ₃ (0.5 wt%, 1 wt%, and 2 wt%) to evaluate their performance in transmission and absorption modes. The effect of varying optical fiber lengths (1 cm, 2 cm, and 3 cm) on the optical spectra was also investigated. The results highlight the potential of MoO ₃ -based composites for selective UV filtering, making them suitable for UV-sensitive devices, personal UV protection, and applications requiring precise wavelength control for optimal performance.