WxMo1-xO2 Nanocrystals Synthesized by WSe2-Assisted Chemical Vapor Deposition Method

Transition metal oxide alloys, with tunable stoichiometric ratio, have garnered significant attention due to their unique electronic structure and diverse chemical properties. However, synthesis of micron-scale, single-crystalline transition metal oxide alloys remains a challenge due to their unique alloy structure and stringent synthesis conditions. Herein, a WSe 2 -assisted chemical vapor deposition method is reported for synthesizing W x Mo 1- x O 2 nanocrystals with various dimensions: nanorods, nanoplates, and nanodots. The microscopic (optical microscope, atomic force microscope, and scanning electron microscope) images reveal that the nanocrystals have well-defined non-layered polyhedral structures. The elemental composition is confirmed by Raman spectroscopy and energy dispersion spectroscopy. The change in phonon symmetry in nanorods and the blue shift of Raman peaks in nanocrystals demonstrate the significant role of the quantum confinement effect. The spatial distribution of the various dimensional nanocrystals provides insights into the possible growth mechanism and the key role of the WSe 2 in growth. The WSe 2 -assisted growth strategy for alloyed nanocrystals can expand the transition metal oxide alloy material library and offer a platform for exploring additional properties of transition metal oxide alloys.