Morphology-engineered α-MoO3 nanostructures via MoS2 transformation for high-performance supercapacitors

Abstract

We report a morphology-engineering strategy to enhance supercapacitor performance by transforming hydrothermally synthesized 1T/2H-MoS₂ nanosheets into α-MoO₃ nanoflakes through controlled thermal annealing. For comparison, α-MoO₃ nanoplates and nanofibers were also prepared via calcination and hydrothermal methods, respectively. Comprehensive structural, morphological, and surface analyses confirmed the formation of phase-pure orthorhombic α-MoO₃ with distinct morphologies. Electrochemical evaluation revealed that the nanoflake morphology exhibited the highest specific capacitance of 755 F g⁻¹ at a scan rate of 5 mV s⁻¹, along with the lowest charge-transfer resistance of 0.14 Ω at a current density of 1 A g⁻¹ in 1 M H₂SO₄, outperforming both the nanoplate and nanofiber counterparts. The superior performance is attributed to the high electrochemically active surface area, abundant accessible redox sites, and efficient ion diffusion pathways provided by the nanoflakes. This work demonstrates a simple, scalable route for producing high-performance α-MoO₃ electrodes, offering valuable insights into morphology–property relationships for next-generation energy storage devices.