Toxic metal pollution is one of the environmental problems that seriously affect water resources and ecosystems. Antimony, recognized for its teratogenic and carcinogenic properties, poses significant health risks due to its widespread presence in natural water sources. In this study, cobalt-doped manganese oxide bimetallic composites were designed as an efficient adsorbent for the antimony removal from water. The adsorbent exhibits robust performance over a range of pH values, achieves a significant adsorption capacity of 591.1 mg/g, and exhibits adsorption equilibrium within 25 min. The effectiveness of the adsorption is attributed to the interaction between metal-O bonds and antimony, as well as the hydrogen bonding. In line with the concept of sustainable development, waste adsorbents are used as negative electrodes for SbO2--based aqueous alkaline batteries. It exhibits a high reversible specific capacity of 122.8 mAh.g(-1). This research not only sheds light on innovative approaches to antimony removal but also opens up avenues for the sustainable reuse of waste materials, in line with the principles of sustainable development.

An organic cathode material for zinc-ion batteries shows a reliable proton transport mechanism. It uses a pyrazine ring as the energy storage unit and H+ as the shuttle ion, enabling high functionality utilization with rapid redox kinetics.

Seeking organic cathode materials with low cost and long cycle life that can be employed for large-scale energy storage remains a significant challenge. This work has synthesized an organic compound, triphenazino[2,3-b](1,4,5,8,9,12-hexaazatriphenylene) (TPHATP), with as high as 87.16% yield. This compound has a highly pi-conjugated and rigid molecular structure, which is synthesized by capping hexaketocyclohexane with three molecules of 2,3-diaminophenazine derived from low-cost o-phenylenediamine, and is used as a cathode material for assembling aqueous rechargeable zinc ion batteries. Both experiments and DFT calculations demonstrate that the redox mechanism of TPHATP is predominantly governed by H+ storage. The Zn-intercalation product of nitride-type compound, is too unstable to form in water. Moreover, the TPHATP cathode exhibits a capacity of as high as 318.3 mAh g-1 at 0.1 A g-1, and maintained a stable capacity of 111.9 mAh g-1 at a large current density of 10 A g-1 for 5000 cycles with only a decay of 0.000512% per cycle. This study provides new insights into understanding pyrazine as an active redox group and offers a potential affordable aqueous battery system for grid-scale energy storage. The organic compound of TPHATP with a large pi conjugated structure and multiple redox sites is synthesized and applied in aqueous rechargeable battery. The system shows excellent electrochemical behavior, and the redox mechanism is explored by the experiments, characterization analysis and the calculation of pKa of discharged state, demonstrating that protons rather than Zn2+ ions are involved in energy storage.image

Quantum mechanics/molecular mechanics (QM/MM) simulations offer an efficient way to model reactions occurring in complex environments. This study introduces a specialized set of charge and Lennard-Jones parameters tailored for electrostatically embedded QM/MM calculations, aiming to accurately model both adsorption processes and catalytic reactions in zirconium-based metal-organic frameworks (Zr-MOFs). To validate our approach, we compare adsorption energies derived from QM/MM simulations against experimental results and Monte Carlo simulation outcomes. The developed parameters showcase the ability of QM/MM simulations to represent long-range electrostatic and van der Waals interactions faithfully. This capability is evidenced by the prediction of adsorption energies with a low root mean square error of 1.1 kcal/mol across a wide range of adsorbates. The practical applicability of our QM/MM model is further illustrated through the study of glucose isomerization and epimerization reactions catalyzed by two structurally distinct Zr-MOF catalysts, UiO-66 and MOF-808. Our QM/MM calculations closely align with experimental activation energies. Importantly, the parameter set introduced here is shown to be compatible with the widely used universal force field (UFF). Moreover, we thoroughly explore how the size of the cluster model and the choice of density functional theory (DFT) methodologies influence the simulation outcomes. This work provides an accurate and computationally efficient framework for modeling complex catalytic reactions within Zr-MOFs, contributing valuable insights into their mechanistic behaviors and facilitating further advancements in this dynamic area of research.

The increasingly limited availability of fresh water has become one of the most prominent challenges of our time, and therefore, producing clean water from unconventional sources is of urgent importance. Water harvesting, a process that utilizes changes in the pressure and temperature to capture atmospheric water, has recently drawn considerable attention. In this study, by employing state-of-the-art Monte Carlo simulations, a large-scale study of similar to 12,000 metal-organic frameworks (MOFs) included in the Computational-Ready Experimental (CoRE) MOF database is conducted for their potential in water harvesting. The outcomes herein identify hundreds of promising adsorbents that can deliver a greater amount of fresh water per adsorption-desorption cycle than current state-of-the-art adsorbents. Analyses on such large amounts of computational data have also shed light on the structure-property relationships. Overall, the results obtained herein offer significant insights into the future development of MOFs as water adsorbents to harvest atmospheric water.

The efficient and high-quality production for hydrogen through water electrolysis at high current densities is crucial for commercial utilization. However, the performance of existing hydrogen evolution reaction (HER) electrocatalysts is far from satisfactory. In this regard, we proposed a method to prepare Rh-Ni(OH)(2) catalyst based on Nickel foam (NF). The hydrolysis galvanic replacement of nickel boride with RhCl3 led to produce a lattice contraction in Ni(OH)(2) due to the rigid pressure generated, resulting in outstanding HER performance at high current densities. It achieves an industrial current density of 500 mA cm(-2) with an overpotential of 130 mV. Furthermore, at the industrially prefer temperature of 80 degrees C, only 67 mV overpotential is required. The catalyst also demonstrated exceptional stability, maintaining excellent performance even after a stability test of 100 days with a current density of 200 mA cm(-2). Through Density-functional theory (DFT) calculations, Rh series reduced the hydrogen adsorption free energy.

ABSTRACTHydrazine hydrate as a hydrogen source has a good effect on nitro reduction, but overuse has environmental toxicity and is prone to over‐hydrogenation, resulting in low selectivity. Herein, we report a magnetically separable Rh/Fe3O4 (1.26 wt%) catalyst containing an optimal Rh content that can completely convert 3‐nitrostyrene to 3‐vinylaniline (> 99% selectivity) using a stoichiometric molar ratio of hydrazine hydrate (‐NO2:N2H4·H2O = 1:1.5). This is due to the synergy between Rh and Fe3O4 and the natural selectivity of N2H4·H2O for nitro. The synergy can reduce the activation energy of the reaction (36.6 kJ/mol), increasing the reduction rate of nitro group and avoiding the combination of active hydrogen species (H*) to H2 as well as the hydrogenation of N2H4 to NH3. Moreover, the active H* produced by N2H4·H2O is different from that produced by H2, and excess dose of N2H4 will inevitably yield H2 thus decline the selectivity.

The nanoconfinement approach for constructing ultra-small nanoparticles has been effectively utilized in the development of non-precious metal catalysts. Herein, the catalyst precursor was prepared by host-guest assembly method, using PCN-222 as the host and 1,1 '-bis(diphenylphosphino) ferrocene (DPPF) as the guest. After calcination, the sub-2 nm iron oxide nanoparticles within a phosphorus-nitrogen co-doped carbon matrix (Fe3O4@P/N-CDCM) was obtained. Benefiting from the nanoconfinement effect, the sub-2 nm Fe3O4 nanoparticles were uniformly dispersed on the P/N-CDCM matrix. As a representative application, Fe3O4@P/N-CDCM-600 showed remarkable catalytic activity in the reduction of various nitroaromatic compounds. Under ambient conditions, the efficient reduction of nitro compounds in aqueous solution led to excellent conversion rates (96-99 %) and selectivity (99 %) within 45 minutes. Additionally, the catalyst maintained high efficiency over 5 cycles without experiencing a noticeable decrease in activity. This work provides an innovative and cost-effective strategy for fabricating highly dispersed non-precious metal nanoparticles.

Understanding the synergistic interplay within tandem reaction systems remains a captivating pursuit in catalysis. In this study, we synthesize a sandwich-like nanostructured catalyst, UiO-66-NH2@(PdAu)@MOF-808, based on metal organic frameworks (MOFs). The PdAu nanoparticles can activate H2, and MOF-808 acts as both the active acidic site and encapsulator, namely "active armor". Benefiting from the synergy of MOF-808 and PdAu NPs, the developed catalyst shows outstanding performance for reductive amination under mild conditions (30 degrees C, 1 atm H2).

Sodium-ion batteries (SIBs) are anticipated to be a potentially more cost-effective alternative to lithium-ion batteries (LIBs) for large-scale energy storage. Carbon materials are practical anodes, but the traditional production of hard carbon for SIBs often requires high temperatures exceeding 1300 degrees C. Aiming for a more economical approach, this work presents a carbon material synthesized through the low-temperature carbonization of 2,3-diaminophenazine and terephthalic acid IPB-C (600). Despite its low specific surface area, this carbon material demonstrates exceptional capacity and cycling stability because of its interlayer warping feature. It delivers a specific capacity of 370 mAh g(-1) at 300 mA g(-1) and maintains 77.98 % capacity retention after 1500 cycles. This research highlights the potential for producing high-capacity carbon negative electrode materials with cost-effective bulk chemicals for SIBs.

Organic cathode materials for aqueous rechargeable zinc batteries (ARZBs) are rapidly gaining prominence, while the exploration of compounds with affordable synthesis, satisfactory electrochemical performance, and understandable mechanisms still remains challenging. In this study, 6,8,15,17-tetraaza-heptacene-5,7,9,14,16,18-hexaone (TAHQ) as an easily synthesized organic cathode material with novel quinone/pyrazine alternately conjugated molecule structure is presented. This organic electrode exhibits good capacity with highly reversible redox reactions, and the influence of multi-active structures on the Zn2+/H+ loading behavior is systematically investigated by ex situ spectroscopy, electrochemical tests, and computation. Both experimental and theoretical studies effectively address the Zn2+/H+ intercalation/deintercalation kinetics. Benefitting from the fused active functionalities, the assembled Zn//TAHQ battery displays a maximum discharge specific capacity of 254.3 mAh g-1 at 0.5 A g-1, and it maintains remarkable cycle performance with 71% capacity retention after 1000 cycles under 5 A g-1. Organic cathode material TAHQ with alternating conjugated molecular structure of quinone/pyrazine was synthesized.The redox mechanism was investigated by characterization and DFT calculation.It was proved that the quinone active unit mainly encapsulated Zn2+2, the pyrazine ring encapsulated H+, and stabilized zinc ions to form a five-membered ring through the interaction of lone pair electrons with Zn2+.image

Constructing an environmentally friendly and efficient electrocatalyst holds important and profound significance for energy-efficient hydrogen production. Replacing the oxygen evolution reaction with a lower potential urea oxidation reaction (UOR) may save energy in water electrolysis to produce hydrogen. The UOR is characterized by its high energy barrier, which results in slow reaction kinetics. In this study, we introduced Ba(OH)2 into Ni(OH)2 to form uniform nanosheets. Due to the introduction of Ba2+, the lattice expansion of Ni(OH)2 was triggered, leading to significant improvement in UOR activity. The catalyst achieved a current density of 100 mA cm-2 at only 1.316 V and exhibited remarkable stability over time. Density functional theory (DFT) calculations demonstrate that the Ba-Ni(OH)2 site significantly reduces the energy barrier for urea adsorption, intermediate steps, and desorption. This work provides a novel and environmentally friendly strategy for constructing energy-efficient and highly efficient catalysts through the doping of alkaline earth metals.

Developing confined heterogeneous catalytic systems with diverse and evenly dispersed active sites is a hot research topic for various applications. However, the issues related to the agglomeration of active nanoparticles, spatial distribution uniformity of active nanoparticles, and coverage of active sites with the participation of surfactant or organic ligand restrict the activity or selectivity. In this work, a confined catalyst Pd(PPh3)4@MOF-808-150 was successfully prepared through a host-guest assembling strategy followed by thermal activation to enhance the rigidity of the catalyst. The synthesized catalyst is employed to generate β-ketoenamines in the cascade reaction involving nitro-reduction and sequential condensation. This catalyst effectively resolves the electronic preference conflict of the two catalytic steps by isolating the different active sites, demonstrating excellent activity and high chemoselectivity. It is generally applicable to the synthesis of many β-ketoenamines, with up to 16 kinds of products that have been successfully prepared with conversion and selectivity up to 99%. The extended synthesis method holds significant potential for developing the nanoconfined catalyst without surfactant encapsulation.

Antimony-based materials are rapidly developing towards industrialization, making it crucial to control potential toxicity and address sustainable antimony management. A strategy has been proposed to remove antimony from wastewater and sustainably convert the resulting antimony-enriched waste adsorbent into electrode materials. Herein, the porphyrin ligand-based zirconium metal-organic framework (PCN-222) was constructed for antimony adsorption. The antimony is initially adsorbed onto the Zr cluster nodes, spreads along the skeleton through hydrogen bonds, and finally terminates at the N-coordination fixed sites in the porphyrin ligand. Afterwards adsorption, the antimony-enriched waste adsorbent is converted to Sb nanoparticles embedded in N-doped porous carbon composite by one-step carbothermal reduction. The composite is applied into SbO2--based aqueous alkaline battery, which displays a high specific capacity with 122.5 mAh/g at 1 A/g and good cycling stability. The work provides valuable insights into the treatment of contaminated water and the management of antimony resources.

Pesticides pose a serious risk to public health, even in trace amounts. The sensitive, rapid, visual, and on-site detection of pesticides in a real sample remains a challenge. Herein, we report a visual and rapid organophosphorus pesticide (OP) sensing device with excellent sensitivity, ease of application, and specificity based on a photothermal effect-based peroxidase (POD) mimetic. The ultrathin MIL-101-NH2(Fe) (Fe-MOF) shell-coated Au nanobipyramide (NBP) not only possesses POD-like activity, but also exhibits excellent photothermal effect under near-infrared (NIR) light. The results reveal that the excellent photo-to-thermal conversion of the Au NBPs can rapidly heat the MIL-101-NH2(Fe) shell, which subsequently induces a markedly enhanced POD-like activity. Using paraoxon-ethyl as model OP, the combination of the OP inhibition effect on the biocatalytic activity of acetylcholinesterase with the inhibition effect of thiocholine on the colorimetric assays of the POD-mimicking FeMOF leads to a significant improved selectivity for OP sensing. In particular, the NIR light irradiation increased the OP detection sensitivity by 100 times. Importantly, based on this detection strategy, a visual test strip with high sensitivity was developed and enabled real-time detection through a simple color analysis software on a smartphone. The successful detection of OP residues in fruit peel using this test strip further confirmed its application potential in real sample analysis.

The rapid development of the world economy and industrialization has brought about the increase of contam-inants in water, which makes the removal and detection of contaminants high priority. Enzyme-based water treatment technology is an efficient and economical method, but its industrial application faces great challenges. The encounter between enzyme and metal-organic frameworks (MOFs) offers a glimmer of hope for solving the above problems, benefiting from the fascinating advantages of MOFs. This review discusses the synthesis stra-tegies of enzyme-MOFs for water treatment and highlights the applications of enzyme-MOFs in water treatment, including removal of emerging contaminants and as an emerging sensing platform for contaminants. Further-more, the conclusions and future perspectives are discussed and delineated. The objective of this review is to provide a new perspective on the emerging enzyme-MOFs-based platform for innovative employment in water treatment and to accelerate the development of this field for early industrial application.

Metal-organic frameworks (MOFs) have recently drawn considerable attention as promising adsorbents to harvest atmospheric water. To achieve an efficient harvesting process, seeking MOFs that demonstrate sharp condensation behavior is the key. Given that the clustering of water molecules in MOFs should be driven by not only MOF-water interactions but also water-water interactions, the spatial arrangement of water adsorption sites in a MOF is therefore crucial. Specifically, this study demonstrates the critical role of continuous adsorption channels (CACs) in MOFs. Such CACs will enable water molecules to stay in proximity and in a continuous manner, thus promoting the formation of hydrogen bonds and, consequently, the clustering of water molecules. We have developed an automatic algorithm to detect CACs based on the energy grid of host-guest interactions and applied the algorithm to more than 2000 diverse structures. The results show that more than 80% of the studied MOFs displaying water condensation at 298 K and 20% relative humidity predicted by Monte Carlo simulations indeed have CACs. The developments herein are anticipated to largely facilitate the future discovery of optimal adsorbents for water harvesting or water-adsorption-related applications in general. A Python-based code for detecting CACs in porous materials is also provided along with this article to employ this approach.

Rational design of three-dimensional(3D) composite with ordered structures and high exposure density of active sites is urgently needed in various fields, including adsorption, catalysis, and battery for energy storage. Here, we fabricate the ultra-thin MnO2 nanosheet assembly via the scabbard-like growth on 3D carbon to achieve ultra-fast adsorption for Sb(III). Among the reported antimony adsorbents to date, it shows the fastest adsorption equi-librium time within 120 s. An ultra-fast mass-transfer coefficient process is achieved with 1.65 x 10-4 cm/s. It can be summarized as a rapid mass transfer process accompanied by an ultra-fast surface reaction rate, while the inner-sphere complexation by C-O and Mn-O plays essential roles in binding antimony. Prospectively, ultra rapid adsorption is a promising way to enable high capacity and fast kinetics in the aqueous SbO2- batteries. Ascribing to the excellent conductivity produced by 3D carbon and the outstanding ultra-fast adsorption capacity generated by MnO2 assembly, the aqueous SbO2- battery exhibits a high discharge capacity of 267.8 mAh/g at 2 A/g. The work will provide a promising strategy for the ultra-fast adsorption of Sb(III) and enlightenment for SbO2- based batteries.

Synthesis of regular morphology catalysts with self-growing substrates is one of the effective methods to solve the problem of easy shedding of heterogeneous catalysts. In this study, Fe-doped Ni12P5 nanorods were prepared by depositing 1,1' -bis (diphenylphosphine) ferrocene (DPPF) on N-doped C/NF. The bottom-up growth of the nanorod is ascribed to the preferential adsorption of DPPF with a P site to NF that is surface-doped with the solid-solving C, and the length of nanorods can reach tens of microns and has good robustness. The N-doped carbon-constrained rod-shaped Fe-doped Ni12P5 catalyst (FeNi12P5/NdC/NF-800) that grows on NF has excellent catalytic performance for the urea oxidation reaction. In addition, the current density can be maintained as high as 100 mA cm-2 and the current attenuation is weak for 12 h, and the rod shape remains good. This work provides a new idea for synthesizing selfgrowing catalysts with regular morphology to improve the performance of heterogeneous catalysts.(c) 2022 Elsevier Inc. All rights reserved.

Semi-hydrogenation usually requires an effective catalyst to ensure selectivity, especially when reducible groups coexist in a molecule. Pd is widely used in the semi-hydrogenation of alkynes to synthesize alkenes, but the selectivity control is still challenging. Herein, we design a catalyst with a semi-encapsulated PdRh alloy heterojunction in a carbon layer for the selective semi-hydrogenation of 3-nitrophenylacetylene (3-NPA). Benefiting from the presence of a PdRh alloy heterojunction and a semi-encapsulated structure, the catalyst delivers good selectivity and maintains high activity. In addition, the carbon shell can ensure the stability of the catalyst and prolong the service life. This study provides ideas for the rational design of a catalyst to achieve a selective hydrogenation reaction for practical applications.