Optimization of Photocatalytic Degradation Conditions of Rose Bengal Dye Using Biomass-Derived Carbon Dots

This study shows synthesis of carbon dots (CDs) using a simple pyrolysis method at 250 °C for discrete durations- 1 h and 2 h using Sorghum as biomass precursor for degradation of Rose bengal (RB) dye. The as-fabricated CDs were analyzed through various techniques, including X-ray diffraction, High-resolution transmission electron microscopy, Fourier transform infrared, X-ray photoelectron spectroscopy, and UV–vis spectroscopy. The as-obtained CDs are turbostratic almost spherical, having particle size in the range of 4.24 nm to 7.09 nm. FTIR measurement analyzed the functional groups present on the surface of CDs. The optical band gap of the CDs decreased from 2.99 eV to 2.39 eV as pyrolysis time increased. In addition to this, a series of experiments were designed to evaluate the interaction of various operating parameters including catalyst amount, pH, initial dye concentration, irradiation time, on degradation efficiency (removal time). With the degradation of 86.10% under UV light irradiation, the synthesized CDs exhibit remarkable capabilities as photocatalysts and offer valuable assistance in decontaminating wastewater.