Titanium carbide-yttrium vanadate composite for sensitive electrochemical detection of 4-nitroaniline

초록

A designed YVO4@TiC composite was prepared to address the inherent conductivity constraints of rare-earth vanadates while maintaining their catalytic selectivity for nitroaromatic compounds. X-ray diffraction (XRD) investigation verifies the presence of tetragonal YVO4(I41/amd) and cubic TiC (Fm-3m) phases, together with peak shifts and lattice distortion that suggest interfacial strain and the establishment of a composite formation. The calculated lattice expansion in YVO4 (a = 7.135 & Aring;, c = 6.301 & Aring;) and contraction in TiC (a = 4.314 & Aring;) indicate bidirectional structural modulation induced by charge redistribution. High-resolution XPS further validates this electronic interaction, since consistent negative shifts in Y 3d and V 2p peaks, along with positive shifts in Ti 2p, validate electron flow from TiC to YVO4, resulting in an internal electric field and a defect-rich interface. The YVO4@TiC-modified SPCE has increased charge-transfer kinetics, characterised by a decreased resistance of 87.37 Omega & sdot;cm2 and improved redox reversibility. The sensor exhibits superior analytical performance for 4-nitroaniline (4-NA), providing an extensive linear range (0.001-828.9 & micro;M), an exceptionally low limit of detection (LOD) of 0.00085 & micro;M, and heightened sensitivity dictated by surface-controlled kinetics. This study shows a correlation between structure, property, and function, demonstrating that interfacial electrical engineering directly influences sensing performance, so providing a solid foundation for advanced electrochemical detection of hazardous nitroaromatic contaminants.

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