A material was fabricated based on the Schiff base reaction to achieve covalent attachment of NH₂-MIL-53(Al) and 3-formylsalicylic acid for fluorimetric detection of Zn²⁺ ions based on inhibition and destruction of CN isomerization and ESIPT.

Capacitive deionization is emerging as an energy-efficient technology for water desalination and research is continuing to find better electrode materials in order to achieve favorable properties and good desalination behavior. In this study, mesoporous carbon spheres (MCSs) were synthesized employing the hard template approach using mesoporous silica nanospheres (MSNs) with a narrow pore size distribution as the hard template and sucrose as a low cost naturally occurring carbon source. The as-synthesized carbon/silica composites were carbonized at three different temperatures of 700, 800 and 900 °C followed by etching. The synthesized MCSs were characterized by a variety of techniques including: small and wide angle X-ray diffraction, Raman spectroscopy, nitrogen sorption studies, scanning electron microscopy, high resolution transmission electron microscopy and contact angle measurements. The electrochemical behavior of the synthesized material was studied using three techniques, namely, cyclic voltammetry, galvanostatic charge/discharge and potentiostatic electrochemical impedance spectroscopy. As a pristine carbon material, the synthesized electrodes in this study exhibited promising properties in comparison with other mesoporous carbon electrodes reported in the literature including: high specific capacitance (163.88 F g⁻¹) at a 1 mV scan rate, superior electrical conductivity, better hydrophilicity and low charge transfer resistance. The desalination potency including the recyclability of the electrodes was evaluated and our material showed reasonable salt adsorption capacity (9.29 mg g⁻¹), which makes the mesoporous carbon spheres (MCSs) in this work stand out as a potential candidate for CDI based water desalination.

A new eco-friendly sensor, 3-((6-((4-chlorobenzylidene)amino)pyridin-2-yl)imino)indolin-2-one (CBAPI) was synthesized and well characterized. The CBAPI sensor was employed for detecting Zn²⁺ and Fe³⁺ ions. It exhibited a low limit of detection at pH 6.0, with values of 2.90, for Zn²⁺ and 3.59 nmol L⁻¹ for Fe³⁺ ions. The sensor demonstrated high selectivity over other interfering cations. Additionally, the high binding constants reflect the great affinity of sensor towards Zn²⁺ and Fe³⁺ ions. To further validate its quantification ability for Zn²⁺ ions, the synthesized CBAPI sensor was used to determine Zn levels in human hair samples, and the results were confirmed using atomic absorption spectroscopy (AAS). The AGREE metric tool was used to assess the method’s environmental impact and practical applicability. These positive outcomes indicated that the new method for detecting Zn²⁺ and Fe³⁺ ions is environmentally friendly and safe for humans. The developed CBAPI sensor represents a potential development in metal ion detection, combining sensitivity, selectivity, and rapidity.