Photocatalytic and Ferric Ion Sensing Properties of a New Three-Dimensional Metal-Organic Framework Based on Cuboctahedral Secondary Building Units

Optical Chemosensors Synthesis and Appplication for Trace Level Metal Ions Detection in Aqueous Media: A Review

In recent years, the development of optical chemosensors for the sensitive and selective detection of trace level metal ions in aqueous media has garnered significant attention within the scientific community. This review article provides a comprehensive overview of the synthesis strategies and applications of optical chemosensors dedicated to the detection of metal ions at low concentrations in water-based environments. The discussion encompasses a wide range of metal ions, including but not limited to heavy metals, transition metals, and rare earth elements, emphasizing their significance in environmental monitoring, industrial processes, and biological systems. The review explores into the synthesis methodologies employed for designing optical chemosensors, discovering diverse materials like organic dyes, nanoparticles, polymers, and hybrid materials. Special attention is given to the design principles that enable the selective recognition of specific metal ions, highlighting the role of ligand chemistry, coordination interactions, and structural modifications. Furthermore, the article thoroughly surveys the analytical performance of optical chemosensors in terms of sensitivity, selectivity, response time, and detection limits. Real-world applications, including water quality assessment, environmental monitoring, and biomedical diagnostics, are extensively covered to underscore the practical relevance of these sensing platforms. Additionally, the review sheds light on emerging trends, challenges, and future prospects in the field, providing insights into potential advancements and innovations. By synthesizing the current state of knowledge on optical chemosensors for trace level metal ions detection. The collective information presented herein not only offers a comprehensive understanding of the existing technologies but also inspires future research endeavors to address the evolving demands in the realm of trace metal ion detection.

Anion-Directed Self-Assembly of Calix[4]arene-Based Silver(I) Coordination Polymers and Photocatalytic Degradation of Organic Pollutants

Coordination polymers (CPs) have recently emerged as promising candidates for heterogeneous photocatalysis due to their structural designability and tunable properties. Herein, we developed two novel Ag(I)-calix[4]arene coordination polymers with the formula {[Ag₂(μ-NO₃)L¹]}_n (CP 1) and {[AgL¹]·PF₆}_n (CP 2) (L¹ = 2-mercapto-5-methyl-1,3,4-thiadiazole resorcinol calix[4]arene). Crystallography revealed that anion coordination and self-inclusion behavior induced the cavitand and silver ions to self-assemble into well-defined CPs 1 and 2 with different topological coordination frameworks, respectively. Furthermore, CPs 1 and 2 display high photocatalytic activity for the photodegradation of rhodamine B (RhB) and methyl orange (MO) in an aqueous solution under mild conditions (WLED and UV irradiation). The comparison results demonstrate that CP 1 exhibited better photocatalytic performance than CP 2, which correlated well with the differences in their molecular structure and HOMO-LUMO energy gaps. The photocatalysis products and possible intermediates were successfully monitored and determined using mass spectrum, gas chromatography, and electron paramagnetic resonance measurements. The rational photocatalysis mechanism was further investigated and proposed.

Current status and prospects of metal-organic frameworks for bone therapy and bone repair

With the development of society, traumatic bone defects caused by accidents, diseases and surgeries have become common, eventually resulting in an increase in bone defects. The treatment of bone defects is characterized by a long period of treatment, high cost and uncontrollable outcomes. Also, it results in complications such as infection and bone discontinuity. Hence, due to this situation, the physical, mental and financial aspects of the patient are severely affected. What's more, such outcomes pose a challenge to orthopaedic surgeons. As a result, bone therapy and bone repair have become a hot topic of interest. In repairing bone defects, materials other than autogenous bone are still unable to provide good biocompatibility, osteogenesis, osteoconductivity and osteoinduction properties at the same time. In addition, the scarcity of autologous bone sources has forced the search for new autologous bone replacement materials. Metal organic frameworks (MOFs) are a new class of developed functional materials that have been widely used in the biomedical field during the recent years due to their porous nature, large specific surface area and diverse structures. With the progress in the investigation into bone treatment and repair, more and more investigators are using MOFs in bone therapy and bone repair. With these viewpoints, in the present perspective, the use of MOFs in bone therapy and bone repair has been summarized, and an insight into the future of MOFs in bone therapy and bone repair has been provided.

Construction strategies to modulate the photocatalytic efficiency of Cd(ii) MOFs to photodegrade organic dyes

Two new tuned 3D Cd(ii) MOFs were synthesized and used as photocatalysts for dye degradation.

Efficient photodegradation of dyes by a new 3D Cd(II) MOF with rare fsh topology

Metal–organic frameworks (MOFs) can be regarded as 3D coordination polymers that adopt ordered porous structures and possess abundant active sites, which make them promising photocatalysts for the degradation of organic...

A new 3D 8-connected Cd(ii) MOF as a potent photocatalyst for oxytetracycline antibiotic degradation

1 exhibits the best photocatalytic decomposition efficiency towards antibiotic OXY. The plausible photocatalytic mechanism has been explained with the help of the density of states calculations and Hirshfeld surface analysis.

Dual Use of Copper-Modified TiO2 Nanotube Arrays as Material for Photocatalytic NH3 Degradation and Relative Humidity Sensing

In this paper, we emphasized the dual application of Cu-modified vertically aligned TiO2 nanotube arrays as photocatalyst and a relative humidity sensor. The TiO2 nanotube arrays were obtained by anodization of the titanium layer prepared using radio frequency magnetron sputtering (RFMS) and modified with different copper concentrations (0.5, 1, 1.5, and 2 M) by a wet-impregnation method. The sample modified with 2 M Cu(NO3)2 solution showed the highest efficiency for the NH3 photocatalytic degradation and the most pronounced humidity response in comparison to the other studied samples. In order to investigate the structure and impact of Cu modification, X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS) were used. The photocatalytic activity and the kinetic study of ammonia oxidation were studied in a mini-photocatalytic wind tunnel reactor (MWPT), while relative humidity sensing was examined by impedance spectroscopy (IS). Higher NH3 oxidation was a direct consequence of the increased generation of •OH radicals obtained by a more efficient photogenerated charge separation, which is correlated with the increase in the DC conductivity.

Tunable Band Gaps in MUV-10(M): A Family of Photoredox-Active MOFs with Earth-Abundant Open Metal Sites

Titanium-based metal-organic frameworks (Ti-MOFs) have attracted intense research attention because they can store charges in the form of Ti³⁺ and they serve as photosensitizers to cocatalysts through heterogeneous photoredox reactions at the MOF-liquid interface. Both the charge storage and charge transfer depend on the redox potentials of the MOF and the molecular substrate, but the factors controlling these energetic aspects are not well understood. Additionally, photocatalysis involving Ti-MOFs relies on cocatalysts rather than the intrinsic Ti reactivity, in part because Ti-MOFs with open metal sites are rare. Here, we report that the class of Ti-MOFs known as MUV-10 can be synthetically modified to include a range of redox-inactive ions with flexible coordination environments that control the energies of the photoactive orbitals. Lewis acidic cations installed in the MOF cluster (Cd²⁺, Sr²⁺, and Ba²⁺) or introduced to the pores (H⁺, Li⁺, Na⁺, K⁺) tune the electronic structure and band gaps of the MOFs. Through the use of optical redox indicators, we report the first direct measurement of the Fermi levels (redox potentials) of photoexcited MOFs in situ. Taken together, these results explain the ability of Ti-MOFs to store charges and provide design principles for achieving heterogeneous photoredox chemistry with electrostatic control.

Four structural diversity MOF-photocatalysts readily prepared for the degradation of the methyl violet dye under UV-visible light

The photocatalytic results demonstrated that all of them displayed efficient photocatalytic performances towards the degradation of methyl violet. The mechanism has been proposed.

1,3-Bis(4′-carboxylatophenoxy)benzene and 3,5-bis(1-imidazoly)pyridine derived Zn(ii)/Cd(ii) coordination polymers: synthesis, structure and photocatalytic properties

Zn(ii) and Cd(ii)-based CPs derived from a 1,3-bis(4′-carboxylatophenoxy)benzene and 3,5-bis(1-imidazoly)pyridine synthesized and their photocatalytic properties for decomposition of methylene blue investigated.

Series of highly stable Cd(ii)-based MOFs as sensitive and selective sensors for detection of nitrofuran antibiotic

The oxygen atom of the MOF ether-bridging group acts as a Lewis base site, improving the connection and allowing the detection of 10 antibiotics through the fluorescence quenching effect.

Effects of ligand functionalization on the band gaps and luminescent properties of a Zr12 oxo-cluster based metal–organic framework

Herein, effective optical band gap engineering of a robust Zr₁₂ oxo-based hcp UiO-66 has been realized through linker functionalization.

Syntheses of a series of lanthanide metal–organic frameworks for efficient UV-light-driven dye degradation: experiment and simulation

Three Ln-MOFs show unique 3,8-connected 3D networks and have been used as photocatalysts for the degradation of organic dye methyl violet under UV light.

Efficient photocatalytic degradation of methyl violet using two new 3D MOFs directed by different carboxylate spacers

Both the MOFs proved to be good candidates for the photocatalytic degradation of methyl violet. The mechanism of these photocatalytic degradations is discussed.

New Cd(ii) coordination polymers bearing Y-shaped tricarboxylate ligands as photocatalysts for dye degradation

Two Cd(ii) coordination polymers derived from a Y-shaped tricarboxylate ligand were synthesized and their photocatalytic properties against decomposition of methylene blue were investigated experimentally and computationally.