Remediation of water containing mercury(ii) using poly-2-aminothiazole intercalated α-zirconium phosphate nanoplates†

Abstract

The effectiveness of organic and inorganic adsorbents in treating water contaminated with potentially toxic elements (PTEs) is primarily influenced by their hydrophilicity and complexation abilities. In this study, a poly(2-aminothiazole)/α-zirconium phosphate nanocomposite (AT@ZrP) was synthesized and evaluated for its potential as an efficient adsorbent for Hg(II) removal, showcasing promising applications in mercury decontamination. The AT@ZrP nanocomposite was fabricated through straightforward hydrothermal synthesis of ZrP nanoplates followed by intercalation with 2-aminothiazole and an in situ oxidative polymerisation process. The results demonstrated that increasing the concentration of NH and SH functional groups significantly improved the Hg(II) complexation capacity of the AT@ZrP composite, achieving an adsorption capacity of 246.0 mg g⁻¹, markedly higher than 21.0 mg g⁻¹ of ZrP nanoplates. Additionally, AT@ZrP exhibited over 90% removal efficiency across a wide range of Hg(II) concentrations (5–100 ppm). The pseudo-second-order kinetic model and the Langmuir adsorption isotherm provided a good description of the experimental results, suggesting that the grafted amine and thiol groups on or between the ZrP nanoplates promoted chemisorption. When several metal ions were present, the composite also showed outstanding selectivity for Hg(II). Notably, its adsorption performance showed minimal decline even after 10 consecutive cycles. Thus, the AT@ZrP nanocomposite represents a reliable and efficient adsorbent for the treatment of industrial wastewater containing Hg(II) ions.