Adsorption and catalytic reduction of basic red 1 dye by nickel nanoparticles hydrogel: A study on kinetics, isotherm, and thermodynamics

Abstract

Various dyes often used in industries are not only non-biodegradable but also carcinogenic. It is vital to eliminate these dyes from textile waste to maintain the health of humans, aquatic animals, and plants in water ecosystems. To tackle this issue, herein a new hydrogel designated as [AMPS (PHE-Ce) /MoC-Ni] was developed by combining acrylamide, cellulose, clay, and nickel salt. The prepared hydrogel was then characterized using various techniques, such as Scanning Electron Microscopy (SEM), UV/visible Spectroscopy, Thermogravimetric Analysis (TGA), Fourier-Transform Infrared (FTIR) spectroscopy, and BET surface area analysis. The prepared hydrogel was proven to be a powerful tool for adsorbing Basic Red-1 dye, a common environmental pollutant, with an notable adsorption capability of 1570 mg/g. The swelling behavior under different pH conditions was also explored; exhibited remarkable swelling properties up to 6139% after 25 h of contact with water. Langmuir isotherm was found to be the best one that explains the sorption data with high regression constant value (0.999), confirming a monolayer adsorption mechanism. The kinetics data was well accommodated by pseudo second order kinetics model with R2 value of 0.9999. The thermodynamics evaluations indicated the process to be endothermic, with a positive enthalpy value of 1548.403 Jmol−1. The positive entropy value of 18.50 J/mol.K was also recorded showing the increase in disorderness at adsorbent and sorbate interface. The prepared hydrogel could be effectively used as alternative of activated carbon due its high swelling capacity which further increases its surface area available for adsorption. The adsorbent also used as catalyst for the reduction of basic red 1 dye.