Carboxymethyl cellulose structured nano-adsorbent for removal of methyl violet from aqueous solution: isotherm and kinetic analyses

Abstract: In the present study, we have synthesized a nano-adsorbent of carboxymethyl cellulose; carboxymethyl cellulose/graphitic-carbon nitride/zinc oxide (CMC/g-C₃N₄/ZnO) by sol–gel technique. It has been utilized for the adsorptional elimination of methyl violet (MV) from aqueous solution. Maximum surface area as determined from the BET analyses is 9.214 m²/g. XRD analysis confirmed the semi-crystalline nature of the nano-adsorbent. Presence of desired functionalities on the surface of nano-adsorbent, CMC/g-C₃N₄/ZnO offered maximum interactions with the MV molecules. Isotherm studies generalized the monolayer adsorption of MV molecules with maximum adsorption capacity of 96.43 mg/g. Solution pH affected the adsorption rate to large extent and maximum occurred at pH 8. Pseudo-second order model better explained the adsorption process that determines the chemical interactions between methyl violet and CMC/g-C₃N₄/ZnO. Graphic abstract: [Figure not available: see fulltext.].