Exploring the adsorption behavior of malachite green dye onto g-C3N4/ZnFeAl-layered triple hydroxide composite

Dye pollution of water is one of the greatest environmental issues which need to be addressed effectively. The current research is aimed at enhancing the adsorption of malachite green dye (MG) on a novel g-C 3 N 4 /ZnFeAl-LTH (LTH -layered triple hydroxide) composite to improve the adsorption capacity. Powder XRD, FTIR, BET, and FESEM were used to characterize the modified materials. The BET surface area of the g-C 3 N 4 /ZnFeAl-LTH composite was found to be 61.658 m 2 /g, providing abundant active sites for adsorption. A number of parameters were optimized to increase the adsorption capacity of g-C 3 N 4 /ZnFeAl-LTH composite. Under the optimal conditions, such as contact time of 180 min, an MG concentration of 120 mg/L, a dosage of 1.6 g/L, and at ambient temperature (33 °C), the g-C 3 N 4 /ZnFeAl-LTH composite showed significantly higher MG removal efficiency of 96.29 ± 0.41 % when compared to pristine g-C 3 N 4 which yielded 73.67 + 0.53 %. The pseudo-second-order model (R 2 = 0.999) was the best kinetic model that explained the adsorption kinetics and the Langmuir isotherm model best described the equilibrium data with a maximum adsorption capacity of 156 mg/g. Significantly, the composite demonstrated excellent reusability, maintaining high removal efficiency over three consecutive adsorption–desorption cycles. • A g-C 3 N 4 /ZnFeAl-LTH composite was successfully synthesized via the co-precipitation method. • The composite showed high MG dye removal efficiency under optimized conditions. • Maximum adsorption capacity of 156 mg/g was achieved, following the Langmuir isotherm model. • The adsorption kinetics followed a pseudo-second-order model, indicating chemisorption.