Electrochemical Detection of 4-Nitrophenol Using a Novel SrTiO<sub>3</sub>/Ag/rGO Composite
Arularasu M. Visagamani, Moussab Harb, K. Kaviyarasu, A. Muthukrishnaraj, A. Manikandan, Khalid A. Alzahrani, Raed H. Althomali, Saja Abdulrahman Althobaiti
Abstract
High Resolution Image Download MS PowerPoint Slide In this study, an eco-friendly strategy was used to prepare a novel SrTiO 3 /Ag/rGO composite. A SrTiO 3 /Ag/rGO composite-modified screen-printed carbon electrode (SPCE) was applied for the electrochemical detection of 4-nitrophenol. A simple ultrasonic method with an ultrasonic frequency of 20 kHz was used for the synthesis of SrTiO 3 /Ag/rGO composite material. The obtained SrTiO 3 /Ag/rGO composite was characterized by X-ray diffraction, Fourier transform infrared, Raman spectroscopy, field emission electron microscopy, and UV–visible spectroscopy. Electrochemical impedance spectroscopy was used to determine the electrical conductivity of the SrTiO 3 /Ag/rGO composite. The electrochemical properties of the modified electrode were studied using cyclic voltammetry as well as linear sweep voltammetry techniques. In comparison to SrTiO 3 /SPCE, SrTiO 3 /Ag/SPCE, and SrTiO 3 /rGO/SPCE electrodes, SrTiO 3 /Ag/rGO/SPCE demonstrates a considerable increase in 4-nitrophenol redox peak current. At optimum conditions, a large linear response range of 0.1–1000 M, with a relatively low limit of detection (0.03 M), outperforms the previously published modified electrode for 4-nitrophenol. Moreover, the SrTiO 3 /Ag/rGO/SPCE electrode-based 4-nitrophenol sensor is distinguished by good selectivity, high stability, and repeatability. Furthermore, SrTiO 3 /Ag/rGO/SPCE contributed to the detection of 4-nitrophenol in river water and drinking water with the recovery range from 97.5 to 98.7%. The experimental finding was supported by density functional theory calculation.