Two new Schiff base fluorescent probes (L and S) were designed for selectively detecting Al³⁺ ions in aqueous medium. Structural characterization of the purely synthesized compounds was acquired by IR, ¹H NMR and ¹³C NMR. Moreover, their photochromic and fluorescent behaviors have been investigated systematically by UV–Vis absorption and fluorescence spectra. The two probes have both high selectivity and sensitivity toward Al³⁺ ions in aqueous medium. The 2:1 stoichiometry between the Al³⁺ and probes was verified by Job’s plot. Moreover, the limits of detection (LOD) for Al³⁺ by L and S were 1.98 × 10⁻⁸ and 4.79 × 10⁻⁸ mol/L, respectively, which was much lower than most previously reported probes. The possible recognition mechanism was that the metal ions would complex with Schiff base probes because of the prevalence of the species optimal for complex formation, inhibiting the structural isomerization of conjugated double bonds (-C=N-), inhibiting the proton transfer process in the excited state of the molecules and resulting in changes of its color and fluorescence behavior. Furthermore, the probes will have potential applications for selectively, detecting Al³⁺ ions in the environmental system with high accuracy and providing a new strategy for the design and synthesis of multi-functional sensors.

Herein, a zeolitic imidazole framework (ZIF-67) composite was prepared by a rapid, simple and inexpensive situ hybridization technique applying polyurethane sponge (PU) as support, which was designated as ZIF-67-PU. The ZIF-67 nanoparticle was successfully supported on the surface of sponge skeletons mainly through electrostatic attraction as well as probable π−π stacking interactions with PAM modification of the sponge. The resultant ZIF-67-PU exhibited a remarkably enhanced U(VI) elimination capacity of 150.86 mg∙g⁻¹ on the basis of the Langmuir isotherm model, in comparison to pristine sponge. Additionally, the mechanism for U(VI) elimination was mainly achieved through the complex reaction between C–N(H)/–OH groups in ZIF-67 and U(VI), based on XPS investigations. ZIF-67-PU represents a simple, feasible and low-cost disposal option for preparing ZIF-coated sponges of any shape that can enhance the U(VI) elimination capacity. Furthermore, this approach can be widely applied to the preparation of various kinds of MOF-sponges through this situ hybridization technique.

One-dimensional shaving-like BiVO₄ nanobelts were successfully synthesized via the oxide hydrothermal method (OHS), using V₂O₅ and Bi₂O₃ as raw materials and PEG 10000 (polyethylene glycol 10000) as a template. Multiple techniques, including XRD, SEM, TEM, HRTEM, UV–Vis, XPS, and photoelectrochemical measurements, were applied to characterize the obtained materials. The thickness of the BiVO₄ nanobelt was approximately 10 nm, while the width was approximately 500 nm. EIS results showed that visible-light illumination caused the photogenerated charge of the BiVO₄ nanobelts to have a faster transfer and a higher separation efficiency. Photocatalytic experiments indicated that with BiVO₄ nanobelts as a catalyst, the degradation rate of MB (methylene blue) was close to 92.4%, and it disintegrated after two hours. Moreover, the pseudo-first-order kinetic model can be used to describe the photodecomposition reaction of MB catalysed by BiVO₄ nanobelts. And this excellent photocatalytic activity of the shaving-like BiVO₄ nanobelts may be related to their special morphology, narrow band gap (~2.19 eV), faster transfer and the separation efficiency of the photogenerated charge, leading to strong absorption in the visible region and improving the separation of the photogenerated electron–hole pairs. These novel monoclinic BiVO₄ nanobelts exhibited great photocatalytic activity and are thus a promising candidate for application in visible-light-responsive photocatalysts.