Comparative robustness and sustainability of in-situ prepared antimony nanoarchitectonics in chitosan/synthesized carboxymethyl chitosan in environmental remediation perspective

Abstract

Due to the rapid race of industrialization natural assets like fresh water has been deteriorated causing lethal effects in living organisms. In the current study robust and sustainable composite of in-situ antimony nanoarchitectonics in chitosan/synthesized carboxymethyl chitosan matrix were synthesized. To improve solubility, metal adsorption and water decontamination, chitosan was modified into carboxymethyl chitosan and the modification was confirmed through various characterization techniques. The characteristic bands in the FTIR spectrum confirm substitution of carboxymethyl group in the chitosan. This was further illustrated that the characteristic proton peaks of CMCh observed at δ = 4.097 to 4.192 ppm, suggesting O-carboxy methylation of chitosan by ¹H NMR. The second order derivative of potentiometric analysis confirmed 0.83 degree of substitution. The antimony (Sb) loaded modified chitosan were confirmed by FTIR and XRD analysis. The potential effectiveness of chitosan matrix was determined and compared toward reductive removal of the Rhodamine b dye. Rhodamine b mitigation is following first order kinetics with R² value of 0.9832 and 0.969 with a constant rate of 0.0977 and 0.2534 ml/min for Sb loaded chitosan and carboxymethyl chitosan respectively. The Sb/CMCh-CFP enables us to achieve 98.5 % mitigation efficiency within 10 min. The CMCh-CFP chelating substrate was found stable and efficient even after 4th batches of cycles with <4 % decrease in efficiency. The in-situ synthesized material was found tailored composite, in terms of dyes remediation, reusability and biocompatibility as compared to chitosan.

Keywords: Carboxymethyl chitosan; Monochloroacetic acid; Reductive removal; Rhodamine b.