Experimental design for optimization of 4-nitrophenol reduction by green synthesized CeO2/g-C3N4/Ag catalyst using response surface methodology

• Published in: Journal of rare earths 2020-11, Vol.38 (11), p.1171-1177
• Main Authors: Pinheiro, Dephan, Sunaja Devi, K.R., Jose, Ajay, Karthik, Kashinathan, Sugunan, Sankaran, Krishna Mohan, Mothi
• Format: Article
• Language: English
• Subjects: 4-Nitrophenol; Box-Behnken design; CeO2/g-C3N4/Ag; Heterogeneous catalysis; Rare earths; Response surface methodology
• ISSN: 1002-0721; 2509-4963
• DOI: 10.1016/j.jre.2019.10.001

In this study, the enhancement of catalytic activity of ceria when modified with co-catalysts such as graphitic carbon nitride and silver was established. The material was synthesized using phytogenic combustion method, a green alternative to the traditional preparative routes. The catalyst was characterized using XRD, FTIR, SEM, EDX, XPS and TEM techniques. The synergistic effect of the composite CeO2/g-C3N4/Ag was tested for catalytic reduction of 4-nitrophenol in the presence of sodium borohydride. The reaction was carried out at room temperature without any light source or external stirring. The individual and combined effects of four parameters, viz., concentration of 4-NP, amount of catalyst, amount of NaBH4 and time for the reduction of reduction 4-NP were investigated using Box-Behnken design of response surface methodology (RSM). This statistical model was used to optimize the reaction conditions for maximum reduction of 4-NP. The optimum conditions for the reduction reaction are found to be 0.01 mmol/L 4-NP, 15 mg catalyst, 20 mg NaBH4 and 13.7 min time interval. CeO2/g-C3N4/Ag catalyst synthesized using Piper betle leaf extract shows good catalytic activity towards the reduction of 4-nitrophenol. The reaction conditions were optimized for maximum efficiency using BBD of RSM. Quick reduction time and green synthetic method make CeO2/g-C3N4/Ag an efficient and eco-friendly catalyst for the reduction of 4-nitrophenol. [Display omitted] •Green synthetic method was used to synthesize CeO2/g-C3N4/Ag catalyst using Piper betle leaf extract.•Catalytic efficiency was evaluated for the reduction of 4-nitrophenol.•Box-Behnken design with RSM was used to establish the influences between variables and to optimize the parameters.•The correlation coefficient of R2 and adjusted R2 of this model were found to be 0.9709 and 0.9369, respectively.