Hydrothermal Synthesis of CrSe Hexagons for Sensitive and Low-level Detection of 4-Nitrophenol in Water.

We report a simple hydrothermal method used for the synthesis of CrSe hexagons (h-CrSe) and its application towards electrochemical sensing of 4-nitrophenol (4-NP). The formation of h-CrSe was confirmed by using scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. The electrochemical activity of the h-CrSe modified screen-printed carbon electrode (SPCE) towards 4-NP was studied using cyclic voltammetry (CV) and amperometric i-t techniques. Typically, the obtained results were compared with those for a bare SPCE. The CV result clearly reveals that h-CrSe modified SPCE has higher catalytic activity towards reduction of 4-NP than bare SPCE. Hence, h-CrSe modified SPCE was concluded as a viable sensor for sensitive determination of 4-NP. Under optimized conditions, h-CrSe modified SPCE demonstrates the excellent capacity to detect the 4-NP in a linear range from 0.05 µM to 908.0 µM. The LOD and sensitivity in detection of 4-NP were determined at 0.01 µM and 1.24 µAµM cm respectively. The sensor is highly selective and stable and shows reproducible recovery of 4-NP in domestic supply and river water samples.