CeO₂ Nanoparticles Modified on Graphite Sheet Electrodes for Photoelectrochemical Tobacco Wastewater Detection, Degradation, and Toxicity Measurement

Monitoring and implementation of gutka wastewater treatment using a fast and feasible fabrication method, owing to the clean water environment, have a great socioeconomic impact. A facile approach is promoted for detecting and degrading nicotine and gutka wastewater by the means of a wide range of ultraviolet light absorption and is applied in our current research. In this report, we successfully synthesized cerium oxide nanoparticles (CeO 2 NPs) by a co-precipitation method for photoelectrochemical (PEC) detection and degradation of smokeless tobacco from wastewater. X-ray diffraction study confirmed the face-centered cubic structure of CeO 2 NPs. Raman analysis and ultraviolet–visible spectroscopy endorsed the formation of CeO 2 NPs. The as-fabricated CeO 2 NP-modified graphite sheet electrode showed high sensitivity (98.1 μA/μM) and good linear range (10–150 nM) for the detection of tobacco from wastewater. The limit of detection was calculated as 0.15 nM. The catalyst photoelectrochemically degraded 93% of nicotine and 94.21% of gutka wastewater at 120 min. Toxicity studies of gutka with an in vivo nematode model, Caenorhabditis elegans, and Vigna radiata proved that PECO-degraded gutka waste had no deleterious effects on the survival (95.43%) ( p < 0.01) of C. elegans when compared to nondegraded gutka waste (11.93%) and did not affect the physiological functions and reactive oxygen species production.