Sol–gel synthesis of gelatin–zirconium(IV) tungstophosphate nanocomposite ion exchanger and application for the estimation of Cd(II) ions

Gelatin–Zr(IV) tungstophosphate (GT/ZTP) nanocomposite ion exchanger was synthesised using simple sol–gel method at pH 0–1. GT/ZTP nanocomposite shows greater value of IEC (0.80 meq/g) as compared to Zr(IV) tungstophosphate (0.32 meq/g). TEM results confirmed the nano size of composite material. Distribution coefficient studies illustrates that the GT/ZTP have higher distribution coefficient values for Cd(II) instead of others. Binary separations of metal ion pairs including Cd(II)–Al(III), Cd(II)–Ni(II), Pb(II)–Mg(II), Mg(II)–Zn(II), Pb(II)–Cu(II), Co(II)–Cu(II), Al(III)–Co(II) and Ni(II)–Zn(II) were attempted using GT/ZTP naocomposite column. The photocatalytic studies showed that 84.61% MV was degraded within 4 h of solar illumination. The kinetics of photocatalytic degradation for methyl violet (MV) was studied by pseudo-first-order kinetic model with higher R² = 0.998. GT/ZTP nanocomposite was exploited for the erection of ion selective membrane electrode to detect Cd(II) in the water system. The electrode possessed wide concentration range, pH range and quick response time.