Optimization of photocatalytic parameters for MB degradation by g-C3N4 nanoparticles using Response Surface Methodology (RSM)

Abstract

In the present paper, graphitic carbon nitride (g-C3N4) was prepared using a conventional hydrothermal process. Several characterization methods were applied to analyze the resulting g-C3N4 sample, such as: X-ray diffraction (XRD), ultraviolet-visible (UV–Vis) spectrophotometry, attenuated total reflectance -Fourier-transform infrared (ATR-FTIR) spectroscopy and scanning electron microscopy (SEM) equipped with energy-dispersive X-ray spectroscopy (EDS). The pollutant selected to measure the g-C3N4 photocatalytic performance was methylene blue (MB). Using Response Surface Methodology (RSM), the pH solution effects, photocatalyst dose (mg/L), and irradiation period (min) were examined and adjusted. The optimal conditions, which included 1.3 g/L of g-C3N4 photocatalyst, solution pH = 10.83, and irradiation time = 119.3 min, resulted in a degradation efficiency of 86.58 %. The principal active species involved in photocatalytic degradation have been identified and a potential mechanism has also been provided. Additionally, the degradation kinetics were monitored and obtained to follow pseudo-second order kinetics.