Synthesis of hollow Mo2C/carbon spheres, and their application to simultaneous electrochemical detection of hydroquinone, catechol, and resorcinol.

Hollow molybdenum-dopamine spheres were synthesized and thermally annealed to form hollow Mo2C/C spheres. The morphology, composition and electrochemical behavior of spheres were characterized. A glassy carbon electrode (GCE) was modified with the spheres and then used for simultaneous detection of hydroquinone (HQ), catechol (CC), and resorcinol (RS). Distinct oxidation peaks can be observed for HQ, CC and RS at potentials of -0.004 V, 0.10 V and 0.44 V (vs. SCE). The responses to HQ, CC and RS are linear in the concentration ranges of 0.3~1000 μM, 2~2000 μM and 3~600 μM, respectively. The corresponding detection limits are 0.12, 0.19 and 1.1 μM (at S/N = 3). The sensor was then applied to quantify HQ, CC, and RS in tap water, river water and vegetable juice. Recoveries ranged from 93.5% to 106.5%. The modified GCE is repeatable, reproducible, stable and selective for HQ, CC and RS. Graphical abstract Schematic presentation of a novel electrochemical sensor based on a glassy carbon electrode modified with  hollow Mo2C/ carbon spheres for determination of hydroquinone, catechol, and resorcinol.