Interfacial charge-transport engineering in a WS2@functionalized carbon black nanocomposite for ultrasensitive electrochemical detection of phloroglucinol

The construction of functional electrochemical composites with specified pathways for charge movement and interface transport for the attainment of state-of-the-art sensing platforms for the detection of environmental phenolic pollutants is of paramount importance. Unlike conventional WS₂-carbon systems, this work focuses on engineering the heterointerface to simultaneously regulate electron and proton transport pathways. In this work, we present a hierarchically structured tungsten disulfide at functionalized carbon black (WS 2 @f-CB) nanocomposite as an advanced electrochemical composite for the detection of phloroglucinol. This composite structure consists of edge-rich WS 2 nanoparticles oxygen-rich carbon black matrix, thus forming a hetero-interface that synergistically promotes rapid electron transport, efficient relay of protons, and selective molecular adsorption. Structural and surface characterizations validate the close interface coupling of WS 2 with f-CB, while the studies conducted on electrochemical impedance and cyclic voltammetry show a relative increase in the electrochemically active surface area with a lowered charge transfer resistance. The WS 2 @f-CB modified electrode suggests a proton-coupled electron transfer process with the known assembly of the composite interface, which is attributed to the excellent electrocatalytic activity towards the oxidation of phloroglucinol. The sensor exhibits excellent reproducibility and high resistance to common interfering species, allowing reliable phloroglucinol quantification across a remarkably wide linear range (0.00178-235.2 µM) with an ultralow detection limit of 1.28 nM. The confirmed applicability of the sensor developed to real water samples exhibits phloroglucinol site recovery and stability. This paper emphasizes the potential of interfacial charge-transport engineering in WS 2 -based carbon composites in the design of advanced electrochemical sensing platforms for environmental monitoring.