Search Results (49)

Copper oxide (CuO) is a narrow-bandgap p-type semiconductor promising for visible-light photocatalysis, yet it suffers from rapid charge recombination and low carrier transfer efficiency. In this study, two distinct CuO photocatalysts were fabricated via different routes: two-dimensional CuO nanosheets derived from annealing a CuBDC metal–organic framework (MOF) precursor, and oriented one-dimensional CuO nanoflower arrays prepared by electrochemical deposition, followed by annealing. The crystal structure, morphology, optical absorption, and photoelectrochemical properties were systematically characterized by XRD, SEM, XPS, UV-Vis spectroscopy, transient photocurrent response, EIS, and PL spectroscopy. The CuO nanoflower thin film exhibits a broad visible-light absorption, a markedly higher photocurrent density (42.25 μA cm⁻²), and lower charge-transfer resistance compared to CuO nanosheets. When evaluated for visible-light photocatalytic degradation of methylene blue (MB), rhodamine B (RhB), and malachite green (MG), the CuO thin film completely degraded MB within 15 min, with an apparent rate constant of 20.15 h⁻¹—approximately three times that of CuO nanosheets. It also showed 1.2- and 1.28-fold higher activity for RhB and MG, respectively. The enhanced performance is attributed to the oriented nanoflower architecture that provides continuous charge transport pathways, suppresses carrier recombination, and extends light propagation via multiple reflections. This work demonstrates that microstructural engineering is an effective strategy to overcome the intrinsic limitations of CuO photocatalysts for wastewater treatment. Full article

This study develops high-performance ammonia sensors based on composites of metal-organic frameworks (MOF-808 and MOF-818) with reduced graphene oxide (rGO). Two sensor architectures were fabricated: interdigital electrodes and silicon micropillar arrays. The MOF-808/rGO composite demonstrated superior sensing performance for 40 ppm NH₃ at room temperature, with faster response kinetics and higher sensitivity compared to pristine rGO and MOF-818/rGO. Silicon micropillar array sensors showed enhanced performance through optimized periodic arrangements, while oxygen plasma surface modification improved both sensor types. Comprehensive testing confirmed that the MOF-808/rGO sensor maintains reliable NH₃ detection at concentrations as low as 5 ppm under high humidity conditions, exhibiting excellent stability and selectivity. These findings provide valuable insights for developing advanced gas sensors for environmental monitoring applications. Full article

The intermittency of renewable-based power is a major barrier for long-term supply of clean energy, which necessitates the development of reliable solutions for clean energy storage and transition towards a carbon-neutral economy. Although hydrogen has emerged as a promising clean energy carrier to address this, its high compressibility requires safe, efficient and practical storage technologies for widespread deployment. Surface storage technologies for hydrogen have garnered attention due to their mobile and stationary applications, paving the way for a future hydrogen-based economy. This review provides a comprehensive review of surface hydrogen storage technologies, covering metal hydrides, metal-organic frameworks (MOFs), liquid organic hydrogen carriers (LOHCs), glass microspheres, capillary arrays, etc. Where previous reviews mostly address the chemistry behind these storage technologies, this study highlights practical integration and techno-economic assessment. Comparative analysis reveals that while LOHC and hydrides dominate in Technology Readiness Level, MOFs and carbohydrate-based systems offer high gravimetric potential, though they are currently quite costly. Other challenges like thermal management and large-scale regeneration remain critical for practical deployment. Moreover, recent advancements in Artificial Intelligence and Machine Learning offer unique insights, demonstrating their growing role in material screening, performance prediction, and the optimization of storage system designs. This review outlines the key challenges and research pathways required to support future deployment. Full article

Lanthanide coordination polymers have been developed at a fast rate during the past two decades due to their appealing applications in the modern field of materials science and emerging technologies like luminescence, magnetism, sensing, gas adsorption, and catalysis. The role of lanthanides in imparting specific properties to the coordination polymers has been fully documented in extensive studies carried out by numerous research groups. It has been shown that because lanthanide(III) ions possess a variable coordination number, they readily build two-dimensional and three-dimensional architectures with definite channels, permanent pores, and distinct surface areas. Due to their strong oxophilic propensity and hard Lewis acid character, lanthanides favor the construction of stable coordination polymers and MOF configurations by strongly binding the coordinating groups of the organic linkers. Associated with palladium complexes, the lanthanide ions provide synergistic effects with Lewis acid sites, beneficial to the catalytic activity. These attractive characteristics of lanthanides enabled them to be fruitfully applied in Pd-Ln coordination polymers with catalytic properties. This review covers an array of Pd-Ln coordination polymers applied as heterogeneous catalysts in Suzuki–Miyaura C(sp²)-C(sp²) cross-coupling reactions. The activity and chemoselectivity of Pd(II) ions and Pd nanoparticles associated in coordination polymers with different lanthanides from a selected array of rare earth elements (Eu, Sm, Eu, Gd, Pr, Nd, Ce, La, or Tb) is discussed. High yields (>99%) are attained under optimized reaction conditions. The specific role of lanthanides and organic ligands in creating sustainable and recyclable heterogeneous Pd catalysts is evidenced. Mechanistic aspects of the C(sp²)-C(sp²) cross-coupling reactions are considered. The synergistic interaction between lanthanides and palladium as well as with the organic ligands is highlighted. Full article

Metal–organic frameworks (MOFs) have emerged as versatile precursors and templates for developing high-performance electrode materials for aqueous zinc-ion batteries (ZIBs), owing to their adjustable porosity, abundant metal-coordination sites, and structural flexibility. Among the diverse array of MOFs investigated, those based on manganese, copper, and cobalt, as well as their derivatives, have shown exceptional potential, exhibiting enhanced redox activity, structural integrity, and advantageous zinc-ion storage kinetics compared with many other MOF systems. This study emphasizes the synthesis methodologies, structural characteristics, and electrochemical benefits of these three significant MOF families. After a succinct overview of MOF chemistry, synthesis methodologies, and fundamental design principles for ZIB electrode materials, the article presents a systematic, comparative evaluation of Mn-MOFs, Cu-MOFs, Co-MOFs and V-MOFs, along with their corresponding metal oxides, sulfides, phosphates, carbon composites, and multidimensional hybrid structures. Recent publications for each MOF type are detailed in separate tables, including synthesis methods, morphological development, electrochemical behavior, and performance metrics. The discourse highlights the distinct properties of each metal center, Mn’s multivalent redox chemistry, Cu’s superior electron transport and coordination adaptability, and Co’s elevated activity and stable structures, which together facilitate improved ion diffusion, substantial reversible capacity, and prolonged cycling durability. Ultimately, existing obstacles and potential research avenues are delineated to advance MOF-based materials for next-generation aqueous ZIB systems. Full article

With the increasing demand for high-energy-density lithium batteries, the role of separators has expanded significantly beyond conventional ion conduction and physical isolation. By integrating sensors and introducing functional coatings, separators have gained the ability to monitor internal states in real time and achieve adaptive regulation. This paper systematically reviews the latest research progress on separators modified with functional materials and coatings to achieve information sensing, intelligent response, and multifunctional integration. Notably, an electrochemical sensor based on MXene/MWCNTs-COOH/MOF-808 has been developed for rapid chemical detection; a fully printed ultra-thin flexible multifunctional sensor array has enabled multi-parameter synchronous monitoring; an ion-selective MOF-808-EDTA separator has induced uniform lithium-ion flux; and a PVDF-HFP/LLZTO/PVDF-HFP trilayer separator has maintained structural integrity at 300 °C. These innovative achievements fully demonstrate the enormous potential of intelligent separators in monitoring internal battery states, inhibiting dendrite growth, preventing thermal runaway, and significantly enhancing battery safety, cycle life, and energy density. This points to a transformative development path for the next generation of batteries with higher safety and intelligence. Full article

The detection of volatile organic compounds (VOCs) at low operating temperatures is critical for public health, environmental monitoring, and industrial safety, yet it remains a significant challenge for conventional sensor technologies. Metal-organic frameworks (MOFs) have emerged as highly versatile precursors for creating advanced sensing materials. This review critically examines the transformation of MOFs into functional catalytic interfaces for low-temperature chemiresistive VOC sensing. We survey the key synthetic strategies, with a focus on controlled pyrolysis, that enable the conversion of insulating MOF precursors into semiconducting derivatives with tailored porosity, morphology, and catalytically active sites. This review establishes the crucial synthesis-structure-performance relationships that govern sensing behavior, analyzing how factors like calcination temperature and precursor composition dictate the final material’s properties. We delve into the underlying chemiresistive sensing mechanisms, supported by evidence from advanced characterization techniques such as in situ DRIFTS and density functional theory (DFT) calculations, which elucidate the role of oxygen vacancies and heterojunctions in enhancing low-temperature catalytic activity. A central focus is placed on the persistent challenges of achieving high selectivity and robust performance in complex, real-world environments. We critically evaluate and compare strategies to mitigate interference from confounding gases and ambient humidity, including intrinsic material design and extrinsic system-level solutions like sensor arrays coupled with machine learning. Finally, this review synthesizes the current state of the art, identifies key bottlenecks related to stability and scalability, and provides a forward-looking perspective on emerging frontiers, including novel device architectures and computational co-design, to guide the future development of practical MOF-derived VOC sensors. Full article

Among various H₂ production methods, splitting water using renewable electricity for H₂ production is regarded as a promising approach due to its high efficiency and zero carbon emissions. The oxygen evolution reaction (OER) is an important part of splitting water, but also the main bottleneck. The anodic oxygen evolution reaction (OER) for water electrolysis technology involves multi-electron/proton transfer and has sluggish reaction kinetics, which is the key obstacle to the overall efficiency of electrolyzing water. Therefore, it is necessary to develop highly efficient and cheap OER electrocatalysts to drive overall water splitting. Herein, a series of efficient RuO₂-Co₃O₄ composites were synthesized via a straightforward three-step process comprising solvothermal synthesis, ion exchange, and calcination. The results indicate that using 10 mg of RuCl₃·xH₂O and 15 mg of Co-MOF precursor in the second ion exchange step is the most effective way to acquire the Co₃O₄-RuO₂-10 (RCO-10) composite with the largest specific area and the best electrocatalytic performance after the calcination process. The optimal Co₃O₄-RuO₂-10 composite powder catalyst displays low overpotential (η₁₀ = 272 mV), a small Tafel slope (64.64 mV dec⁻¹), and good electrochemical stability in alkaline electrolyte; the overall performance of Co₃O₄-RuO₂-10 surpasses that of many related cobalt-based oxide catalysts. Furthermore, through integration with a carbon cloth substrate, Co₃O₄-RuO₂-10/CC can be directly used as a self-supporting electrode with high stability. This work presents a straightforward method to design Co₃O₄-RuO₂ composite array catalysts for high-performance electrocatalytic OER performance. Full article

Atherosclerosis is a progressive, multifactorial disease driven by the interplay of lipid dysregulation, chronic inflammation, oxidative stress, and maladaptive vascular remodeling. Despite advances in systemic lipid-lowering and anti-inflammatory therapies, residual cardiovascular risk persists, highlighting the need for more precise interventions. Targeted drug delivery represents a transformative strategy, offering the potential to modulate key pathogenic processes within atherosclerotic plaques while minimizing systemic exposure and off-target effects. Recent innovations span a diverse array of platforms, including nanoparticles, liposomes, exosomes, polymeric carriers, and metal–organic frameworks (MOFs), engineered to engage distinct pathological features such as inflamed endothelium, dysfunctional macrophages, oxidative microenvironments, and aberrant lipid metabolism. Ligand-based, biomimetic, and stimuli-responsive delivery systems further enhance spatial and temporal precision. In parallel, advances in in-silico modeling and imaging-guided approaches are accelerating the rational design of multifunctional nanotherapeutics with theranostic capabilities. Beyond targeting lipids and inflammation, emerging strategies seek to modulate immune checkpoints, restore endothelial homeostasis, and reprogram plaque-resident macrophages. This review provides an integrated overview of the mechanistic underpinnings of atherogenesis and highlights state-of-the-art targeted delivery systems under preclinical and clinical investigation. By synthesizing recent advances, we aim to elucidate how precision-guided drug delivery is reshaping the therapeutic landscape of atherosclerosis and to chart future directions toward clinical translation and personalized vascular medicine. Full article

Flexible supercapacitors have emerged as pivotal energy storage components in wearable smart electronic systems, owing to their exceptional electrochemical performance. However, the widespread application of flexible supercapacitors in smart electronic devices is significantly hindered by the developmental bottleneck of high-performance anode materials. In this study, a novel electrode composed of surface-modified Fe₂O₃ nanoneedles uniformly coated with a polypyrrole (PPy) film and anchored on Co-MOF-derived N-C nanoflake arrays (PPy/Fe₂O₃/N-C) is designed. This composite electrode, grown in situ on carbon cloth (CC), demonstrated outstanding specific capacity, rate performance, and mechanical flexibility, attributed to its unique hierarchical 3D arrayed structure and the protective PPy layer. The fabricated PPy/Fe₂O₃/N-C@CC (P-FONC) composite electrode exhibited an excellent specific capacitance of 356.6 mF cm⁻² (143 F g⁻¹) at a current density of 2 mA cm⁻². The current density increased to 20 mA cm⁻², and the composite electrode material preserved a specific capacitance of 278 mF cm⁻² (112 F g⁻¹). Furthermore, the assembled quasi-solid-state Mn/Fe asymmetric supercapacitor, configured with P-FONC as the negative electrode and MnO₂/N-C@CC as the positive electrode, demonstrated robust chemical stability and notable mechanical flexibility. This study sheds fresh light on the creation of three-dimensional composite electrode materials for highly efficient, flexible energy storage systems. Full article

Metal–organic frameworks (MOFs) based on the pressure swing adsorption (PSA) process show great promise in separating argon from air. As research burgeons, the number of MOFs has grown exponentially, rendering the experimental identification of materials with significant gas separation potential impractical. This study introduced a high-throughput screening through a two-step strategy based on structure–property relationships, which leveraged Grand Canonical Monte Carlo (GCMC) simulations, to swiftly and precisely identify high-performance MOF adsorbents capable of separating argon from air among a vast array of MOFs. Compared to traditional approaches for material development and screening, this method significantly reduced both experimental and computational resource requirements. This research pre-screened 12,020 experimental MOFs from a computationally ready experimental MOF (CoRE MOF) database down to 7328 and then selected 4083 promising candidates through structure–performance correlation. These MOFs underwent GCMC simulation assessments, showing superior adsorption performance to traditional molecular sieves. In addition, an in-depth discussion was conducted on the structural characteristics and metal atoms among the best-performing MOFs, as well as the effects of temperature, pressure, and real gas conditions on their adsorption properties. This work provides a new direction for synthesizing next-generation MOFs for efficient argon separation in labs, contributing to energy conservation and consumption reduction in the production of high-purity argon gas. Full article

With the rapid increase in polyethylene terephthalate (PET) usage in recent years, recycling has become indispensable in mitigating environmental damage and safeguarding natural resources. In this context, this study presents a methodology for valorizing PET waste through phase transfer catalytic hydrolysis conducted at a low temperature (80 °C) and atmospheric pressure, with the goal of recovering the terephthalic acid (TPA) monomer. The recovered TPA monomer was subsequently utilized as a precursor for the synthesis of metal–organic frameworks (MOFs). Tributylhexadecyl phosphonium bromide (3Bu6DPB) was selected as the phase transfer catalyst due to its efficiency and sustainability. The process parameters, including the concentration of NaOH, the wt.% of catalyst to PET, and the concentration of PET in the solution, were varied to optimize the hydrolysis reaction. The Taguchi design methodology with an L9 (3^3) orthogonal array was employed to analyze the influence of these factors on the depolymerization time. The analysis of variance (ANOVA) results revealed that the concentration of NaOH was the most significant factor, contributing to 93.3% of the process efficiency, followed by the wt.% of the catalyst to PET (6.5%). The findings also demonstrated that the concentration of NaOH had the greatest impact (Δ = 4.27, rank = 1), while the concentration of PET had the smallest effect (Δ = 0.16, rank = 3). The optimal conditions for PET depolymerization were achieved in 75 min with 20 g/100 mL of NaOH, 12 wt.% of catalyst to PET, and 5 g/100 mL of PET. The recovered TPA monomer was further employed as an organic ligand to synthesize Fe(III)-TPA MOFs under mild conditions (80 °C for 24 h). The X-ray diffraction (XRD) analysis revealed the simultaneous formation of MOF-235(Fe) and MIL-101(Fe), two multifunctional materials with diverse properties and applications. This study highlights an efficient approach for producing low-cost MOFs while promoting urban waste recycling, contributing to an integrated strategy for PET recycling and resource valorization. Full article

The urea electro-oxidation reaction (UOR) is emerging as a new energy conversion technology and a promising method for alleviating water eutrophication problems. However, a rationally designed structure of the electrode materials is urgently required to achieve high UOR performance. Herein, P-doped MOF-derived Co₃O₄ nanowire arrays grown on nickel foam (P-Co₃O₄/NF) are successfully synthesized via the growth of Co-MOF and subsequent calcination followed by phosphorization treatment. Owing to the optimized electronic structure, the as-prepared P-Co₃O₄/NF composite exhibits much higher UOR electrocatalytic performance than the undoped Co₃O₄/NF sample. Beyond this, the meticulous structure of the one-dimensional nanowire arrays and the three-dimensional skeleton structure of nickel foam contribute to the enhanced electrocatalytic activity and stability toward UOR. As a result, the P-Co₃O₄/NF composite displays a low overpotential of 1.419 V vs. RHE at 50 mA cm⁻², a small Tafel slope of 82 mV dec⁻¹, as well as favorable long-term stability over 65,000 s in 1.0 M KOH with 1.0 M urea. This work opens a new avenue in designing non-precious electrocatalysts for high-performance urea electro-oxidation reactions. Full article

Metal–organic frameworks (MOFs) with redox metal centers have come into view as potential materials for electrochemical energy storage. However, the poor electrical conductivity largely impedes the potentiality of MOFs to construct high-performance electrodes in supercapacitors. In this work, a self-dissociation strategy has been applied to construct Ni-MOF microbelts on Ni foam (NF), where the NF is used as both a support and a Ni source. The transmission channels between the Ni-MOF and NF are favorable for the charge transport due to the in situ self-assembly of the TPA linkers with the dissociated Ni ions from the Ni foam. The grown Ni-MOF microbelt arrays can offer abundant active sites for redox reactions. The prepared Ni-MOF/NF-s electrode can yield a high capacitance of 1124 F g⁻¹ at 1 A g⁻¹ and retains 590 F g⁻¹ at 10 A g⁻¹. This design may offer a controllable protocol for the construction of MOF microbelt arrays on various metal substrates. Full article

The development of supercapacitors with ultrahigh power density, high energy density, and compatible integration for wearable microelectronic devices is significant but challenging. Herein, a bimetallic metal–organic framework (Ni/Co-MOF) with oriented nanosheets was obtained via triethylamine (TEA) guiding using a hydrothermal treatment, in which the TEA guides the vertically oriented array structures of the Ni/Co-MOF and ensures a fast ion/electron transmission path. Subsequently, an asymmetric supercapacitor was rationally designed by applying the bimetallic MOF cathode and an activated carbon (AC) anode. The obtained Ni/Co-MOF sample offers a high storage capacity of 2034 F g⁻¹ at 0.5 A g⁻¹ by harnessing the optimized Ni/Co-MOF with uniformly oriented nanosheet arrays. The constructed asymmetric supercapacitors exhibited a large voltage window of 1.4 V in 3.0 M KOH and an outstanding energy density of 29.5 Wh kg⁻¹ at a power density of 199.1 W kg⁻¹ was obtained, with a remarkable capacitance retention of 89% after 2000 cycles. Full article