Self-assembly encapsulation of vanadium tetrasulfide into nitrogen doped biomass-derived porous carbon as a high performance electrochemical sensor for xanthine determination

Abstract

A self-assembly strategy is presented in this work for the synthesis of vanadium tetrasulfide nanospheres (VS₄) embedded into nitrogen-doped biomass-derived porous carbon materials (VS₄@N-BPC) utilizing birch bark as the biomass-based carbon source via a hydrothermal carbonization method. The fabricated VS₄@N-BPC has the intrinsic features of both hierarchical connectivity and a unique porous structure, providing electron/mass transport with highly efficient pathways. The VS₄ nanospheres are confined by the unique biomass-derived carbon into the microstructural carbon network, which prevents the VS₄ nanospheres from aggregating, enhances their conductivity, and alleviates big volume expansion/contraction consequences, leading to an excellent cycling durability and electrochemical performance. In addition, the nitrogen doping boosts the electrical conductivity, and the carbon framework's surface polarity. The VS₄@N-BPC shows great sensing activity, which is derived from its unique structure and the robust interfacial interaction, with a low detection limit (0.053 μM), a wide linear range (from 0.092 μM to 163.6 μM), strong anti-interference capability, and good stability for xanthine determination, which is better than some previously reported xanthine sensors. Importantly, the satisfactory recoveries obtained from the human urine test implied its feasibility for use in realistic applications. With these brilliant characteristics, the proposed VS₄@N-BPC could be utilized for subsequent analytical applications in real samples.