Platelet Nitrogen and Sulfur Co-Doped Ordered Mesoporous Carbon with Inexpensive Methylene Blue as a Single Precursor for Electrochemical Detection of Herbicide Amitrole

Abstract

Heteroatom-doped ordered mesoporous carbons (OMCs) have currently been considered as promising electrode materials for electrochemical sensors due to the combined advantages of ordered mesoporous materials and heteroatom-doped carbon materials. Herein, a novel nitrogen and sulfur co-doped OMCs (N,S-OMC) has been prepared via a nanocasting strategy with an inexpensive methylene blue as single precursor. The obtained mesoporous carbon has platelet morphology, short mesoporous channel together with a large surface area (549[Formula: see text]m2/g) as well as rich N- and S-containing functional groups (6.8[Formula: see text]at.% N and 2.3[Formula: see text]at.% S). Compared with the graphene (GR) and carbon nanotube (CNT) electrode material, the N,S-OMC exhibited a higher electrochemical activity towards the oxidation of herbicide amitrole, ascribable to N,S-OMC’s open mesoporous structures and abundant electroactive defect sites on the carbon skeleton. And, an amitrole electrochemical sensor with N,S-OMC modified electrode as working electrode was fabricated, exhibiting a good selectivity, stability, reproducibility and wide linear range of 3–750[Formula: see text][Formula: see text]M. Moreover, the N,S-OMC-based electrochemical sensor was proved feasible in river water sample analyses, showing a satisfied recovery ranging from 97.03% to 105.42%. The results not only demonstrate cheap methylene blue can be used as single precursor for the N,S-OMC preparation, but also confirm the N,S-OMC is promising in amitrole sensor fabrication.