Synergism of Holmium Orthovanadate/Phosphorus-Doped Carbon Nitride Nanocomposite: Nonenzymatic Electrochemical Detection of Hydrogen Peroxide

Developing efficient and robust electrode materials for electrochemical sensors is critical for real-time analysis. In this paper, a hierarchical holmium vanadate/phosphorus-doped graphitic carbon nitride (HoVO₄/P-CN) nanocomposite is synthesized and used as an electrode material for electrochemical detection of hydrogen peroxide (H₂O₂). The HoVO₄/P-CN nanocomposite exhibits superior electrocatalytic activity at a peak potential of −0.412 V toward H₂O₂ reduction in alkaline electrolytes while compared with other reported electrocatalysts. The HoVO₄/P-CN electrochemical platform operated under the optimized conditions shows excellent analytical performance for H₂O₂ detection with a linear concentration range of 0.009–77.4 μM, a high sensitivity of 0.72 μA μM^–1 cm^–2, and a low detection limit of 3.0 nΜ. Furthermore, the HoVO₄/P-CN-modified electrode exhibits high selectivity, remarkable stability, good repeatability, and satisfactory reproducibility in detecting H₂O₂. Its superior performance can be attributed to a large specific surface area, high conductivity, more active surface sites, unique structure, and synergistic action of HoVO₄ and P-CN to benefit enhanced electrochemical activity. The proposed HoVO₄/P-CN electrochemical platform is effectively applied to ascertain the quantity of H₂O₂ in food and biological samples. This work outlines a promising and effectual strategy for the sensitive electrochemical detection of H₂O₂ in real-world samples.