Sulfur-doped graphitic C3N4 decorated on cauliflower-like CaMoO4: An efficient electrocatalyst for electrochemical detection of carcinogenic organic pollutant (metol)

Abstract

Environmental monitoring of organic pollutants in water sources is crucial for protecting human health and ecosystem sustainability. Herein, we develop a highly active electrocatalyst composite consisting of cauliflower-like calcium molybdate (CaMoO₄) decorated with sulfur-doped graphitic carbon nitride (S-C₃N₄) for the ultrasensitive electrochemical detection of organic pollutant metol. Various microscopic and spectroscopic techniques were employed to analyze the structural and compositional characteristics of the S-C₃N₄/CaMoO₄ composite. The electrochemical sensor with the optimized S-C₃N₄/CaMoO₄ composite demonstrates a high sensitivity of 3.93 μA μM^-1 cm^-2 and a low limit of detection of 0.002 μM in a wide linear range (0.01-134 μM) by the DPV method. The excellent performance can be attributed to their high conductivity, high surface area, swift electron transportation, favorable active sites, and synergistic effect. Besides, the proposed electrochemical sensor exhibits good reproducibility and remarkable selectivity in the presence of various potential interference compounds in water sources. Its practical applicability for environmental monitoring is verified by quantifying metol in tap water, lake water, and river water. This work highlights the feasibility of rapid and robust electrochemical sensing of the organic pollutant metol at low concentrations and validates its suitability for the in-field applications.

Keywords: Binary metal oxide; Heteroatom material; Organic pollutant; Two-dimensional materials.