Efficient structure tuning over the defective modulated zirconium metal organic framework with active coordinate surface for photocatalyst CO2 reduction

Pt-N catalytic centres concisely enhance interfacial charge transfer in amines functionalized Pt@MOFs for selective conversion of CO2 to CH4

Improving ligand-to-active metal charge transfer (LAMCT) by finely tuning the organic ligand is a decisive strategy to enhance charge transfer in metal organic frameworks (MOFs)-based catalysts. However, in most MOFs loaded with active metal catalysts, electron transmission encounters massive obstacle at the interface between the two constituents owing to poor LAMCT. Herein, amines (-NH2) functionalized MOFs (NH2-MIL-101(Cr)) encapsulated active metal Pt nanoclusters (NCs) catalysts are synthesized by the polyol reduction method and utilized for the photoreduction of CO2. Surprisingly, the introduction of -NH2 (electron donating) groups within the matrix of MIL-101(Cr) improved the electron migration through the LAMCT process, fostering a synergistic interaction with Pt. The combined experimental analysis exposed the high number of metallic Pt (Pt0) in Pt@NH2-MIL-101(Cr) catalyst through seamless electron shuttling from N of -NH2 group to excited Pt generating versatile hybrid Pt-N catalytic centres. Consequently, these versatile hybrid catalytic centres act as electro-nucleophilic centres, which enable the efficient and selective conversion of CO bond in CO2 to harvest CH4 (131.0 µmol.g-1) and maintain excellent stability and selectivity for consecutive five rounds, superior to Pt@MIL-101(Cr) and most reported catalysts. Our study verified that the precise tuning of organic ligands in MOFs immensely improves the surface-active centres, electron migration, and catalytic selectivity of the excited Pt NCs catalysts encaged inside MOFs through an improved LAMCT pathway.

Preferential growth and electron trap synergistically promoting photoreduction CO2 of Tm ion doping bismuth titanate nanosheets

In this study, we prepared two-dimensional Bi4Ti3O12 nanosheets doped with rare earth ions. The experimental results show that Bi4-xTmxTi3O12 exhibits the highest reduction performance among various rare earth doped Bi4Ti3O12 materials, with a CO yield of 7.25 μmol g-1h-1. Furthermore, a delayed reaction in Bi3.97Tm0.03Ti3O12 is observed upon a cessation of light irradiation. Theoretical calculations reveal that the introduction of Tm ion not only reduces the surface energy of (001) plane and make it preferential growth in Bi4Ti3O12, but also brings the intervening energy level of Tm ion (4f and 4d mixed orbital), which is closer to the conduction band of Bi4Ti3O12 and facilitates charge carrier accumulation in trap states. The electrons retained in the shallow traps promote the hysteresis reaction following a cessation of illumination. This work provides further insights into elucidating precise reduction reaction mechanisms underlying rare earth dopant on photocatalysts. This research provides enhanced insights into unraveling the precise reduction reaction mechanisms influenced by rare earth dopants in photocatalysts.

Preparation of visible-light active MOFs-Perovskites (ZIF-67/LaFeO3) nanocatalysts for exceptional CO2 conversion, organic pollutants and antibiotics degradation

Modern industries rapid expansion has heightened energy needs and accelerated fossil fuel depletion, contributing to global warming. Additionally, organic pollutants present substantial risks to aquatic ecosystems due to their stability, insolubility, and non-biodegradability. Scientists are currently researching high-performance materials to address these issues. LaFeO3 nanosheets (LFO-NS) were synthesized in this study using a solvothermal method with polyvinylpyrrolidone (PVP) as a soft template. The LFO-NS demonstrate superior performance, large surface area and charge separation than that of LaFeO3 nanoparticles (LFO-NP). The LFO-NS performance is further upgraded by incorporating ZIF-67. Our results confirmed the ZIF-67/LFO-NS nanocomposite have superior performances than pure LFO-NP and ZIF-67. The integration of ZIF-67 has enhanced the charge separation and promote the surface area of LFO-NSwhich was confirmed by various characterization techniques including TEM, HRTEM, DRS, EDX, XRD, FS, XPS, FT-IR, BET, PL, and RAMAN. The 5ZIF-67/LFO-NS sample showed significant activities for CO2 conversion, malachite green degradation, and antibiotics (cefazolin, oxacillin, and vancomycin) degradation. Furthermore, stability tests have confirmed that our optimal sample very active and stable. Furthermore, based on scavenger experiments and the photocatalytic degradation pathways, it has been established that H+ and •O2- are vital in the decomposition of MG and antibiotics. Our research work will open new gateways to prepare MOFs-Perovskites nanocatalysts for exceptional CO2 conversion, organic pollutants and antibiotics degradation.

A critical review on metal-organic frameworks (MOFs) based nanomaterials for biomedical applications: Designing, recent trends, challenges, and prospects

Nanomaterials (NMs) have garnered significant attention in recent decades due to their versatile applications in a wide range of fields. Thanks to their tiny size, enhanced surface modifications, impressive volume-to-surface area ratio, magnetic properties, and customized optical dispersion. NMs experienced an incredible upsurge in biomedical applications including diagnostics, therapeutics, and drug delivery. This minireview will focus on notable examples of NMs that tackle important issues, demonstrating various aspects such as their design, synthesis, morphology, classification, and use in cutting-edge applications. Furthermore, we have classified and outlined the distinctive characteristics of the advanced NMs as nanoscale particles and hybrid NMs. Meanwhile, we emphasize the incredible potential of metal-organic frameworks (MOFs), a highly versatile group of NMs. These MOFs have gained recognition as promising candidates for a wide range of bio-applications, including bioimaging, biosensing, antiviral therapy, anticancer therapy, nanomedicines, theranostics, immunotherapy, photodynamic therapy, photothermal therapy, gene therapy, and drug delivery. Although advanced NMs have shown great potential in the biomedical field, their use in clinical applications is still limited by issues such as stability, cytotoxicity, biocompatibility, and health concerns. This review article provides a thorough analysis offering valuable insights for researchers investigating to explore new design, development, and expansion opportunities. Remarkably, we ponder the prospects of NMs and nanocomposites in conjunction with current technology.