Synergistic effects of vanadium incorporation in MoP2 nanoflowers toward integrated wastewater treatment and electrochemical energy storage

Abstract

This study reports the synthesis of vanadium-incorporated molybdenum diphosphide (V doped-MoP₂) nanomaterials for dual-functional applications in wastewater treatment and energy storage. Structural and morphological analyses reveal that V-doping significantly reduces the crystallite size from 70 nm to 28 nm, yielding sharp petal-like features that enhance the surface-to-volume ratio. Optical studies confirm that 7 wt% V-inclusion narrows the bandgap from 2.77 eV to 2.56 eV and effectively suppresses electron–hole recombination. Consequently, the 7 wt% V doped-MoP₂ photocatalyst achieved 94% degradation of methylene blue under visible light, with a rate constant five times higher than that of pristine MoP₂ and excellent reusability (92% after 4 cycles). As a supercapacitor electrode, the 7 wt% V doped-MoP₂ sample exhibited a superior specific capacitance of 2304 F g⁻¹ at 1 A g⁻¹ and 2280 F g⁻¹ at 5 mV s⁻¹. EIS confirmed enhanced reaction kinetics and efficient mass transfer. Furthermore, the material demonstrated remarkable long-term stability, maintaining 95.2% and 91.5% capacity retention after 5000 CV and GCD cycles, respectively. These results highlight V-doping as a potent strategy for engineering high-performance MoP₂-based materials for environmental remediation and advanced energy storage systems.