Ag/LDH-itaconic acid-gellan gam nanocomposites: Facile and green synthesis, characterization, and excellent catalytic reduction of 4-nitrophenol

The catalytic reduction reaction is one of the most commonly used solutions to convert high-risk contaminants into safe or low-risk materials. Today, with the increasing water pollution, the urgent need for efficient and effective catalysts is felt more than ever. For this purpose, for the first time, a green catalyst composed of silver nanoparticles anchored on itaconic acid-modified Ca-Al layered double hydroxide/gellan gum nanocomposite (Ag/LDH-ITA-GG NC) was prepared from a green approach without the use of any toxic organic solvents. To gain an in-depth insight into the physicochemical properties of the catalyst, different techniques including nitrogen adsorption-desorption isotherms, FESEM/mapping, FTIR, TGA, and XRD were used. The catalytic performance of the Ag/LDH-ITA-GG NC toward 4-nitrophenol reduction by NaBH4 was investigated. The calculated values of the apparent rate constant for this reaction are 0.2142 min-1 (for 1.0 mg of the catalyst), 0.2375 min-1 (for 3.0 mg of the catalyst), and 0.2550 min-1 (for 5.0 mg of the catalyst), indicating that the catalytic conversion of 4-nitrophenol to 4-aminophenol on the Ag/LDH-ITA-GG NC catalyst follows the pseudo-first-order kinetics and is comparable to the previous findings in the literature. The results of this study indicated that Ag/LDH-ITA-GG NC can potentially be utilized as an auspicious high efficient green catalyst for the reduction of pollutants like 4-nitrophenol.