RSM approach for process optimization of the photodegradation of congo red by a novel NiCo ₂S ₄/chitosan photocatalyst

Abstract

The current study reported a facile co-precipitation technique for synthesizing novel NiCo ₂S ₄/chitosan nanocomposite. The photocatalytic activity of the prepared nanocomposite was evaluated using congo red (CR) dye as a target pollutant. The central composite design was employed to examine the impact of different reaction conditions on CR dye degradation. This study selected the pH, photocatalyst loading, initial CR concentration and reaction time as reaction parameters, while the degradation efficiency (%) was selected as the response. A desirability factor of 1 suggested the adequacy of the model. Maximum degradation of 93.46% of 35 ppm dye solution was observed after 60 min of visible light irradiation. The response to surface methodology (RSM) is a helpful technique to predict the optimum reaction conditions of the photodegradation of CR dye. Moreover, NiCo ₂S ₄/Ch displayed high recyclability and reusability up to four consecutive cycles. The present study suggests that the prepared NiCo ₂S ₄/chitosan nanocomposite could prove to be a viable photocatalyst for the treatment of dye-contaminated wastewater.