In-situ growth of tungsten oxide reinforced by liquid metal for electrochemical determination of lead ions

Metal oxides with the remarkable interfacial activity and selective absorption properties in the electrochemical detection of heavy metals ions, are still challenging to synthesize due to agglomeration and inferior electrical conductivity. A tungsten oxide/liquid metal/copper foam (WO3-LM-Cu) hierarchical tandem electroabsorption was rationally designed and fabricated in this work. The alloying effects of gallium-based liquid metal promoted the uniform growth and conductivity of WO3 nanoparticles, and the cuboid-shaped structure optimized for intense heavy metal ion adsorption via the valence transfer of tungsten oxide. Then, the influences of electrochemical parameters, such as electrolyte pH, deposition potential, and enrichment time on detection performance were investigated. The resulting sensor demonstrated a wide linear range (20–100 ppb) and superior limits of detection (0.0878 ppb) for detection of lead ions, exhibiting excellent anti-interference ability and satisfactory repeatability (RSD < 1.25 %, n=7). This work offers a simplified and dependable methodology for fabricating self-supporting metal oxide electrodes that exhibit exceptional detection capabilities, paving the way for significant advancements in the application of tungsten oxide for electrochemical detection of heavy metal ions. •Application of room temperature liquid metal drives the uniformly growth of WO3 on Cu substrate.•The homogeneous surface is primarily contributing to electrochemical detection of lead ions.•The sensor can detect various concentration lead ions.