Nanofiltration (NF) is a key water treatment technology crucial for addressing the global water resource crisis. The precise control over the inner microstructure of the membrane presents a critical issue that must be addressed to achieve superior separation performance. Herein, vertical NiAl-layered double hydroxide (LDH) nanoarrays were synthesized and employed as an intermediate layer during interfacial polymerization (IP) to fabricate LDH/polyamide (PA) composite membranes. The vertical LDH arrays can bidirectionally regulate the internal microstructure of the PA layer. At a lower PIP concentration (0.1 w/v%), the hydroxyl groups on LDH delay the diffusion of PIP via hydrogen bonding, resulting in a 24 nm active PA layer with the looser structure (compared with pristine PA (0.1%)). The membrane displayed a permeance value of 65 L m-2 h-1 bar-1 with the methyl blue (MB) rejection of 98.5%, and enabled precise separation of MB and methyl orange (MO). At a higher PIP concentration (1 w/v%), the LDH arrays can effectively store and rapidly release PIP to obtain a complete initial polymer membrane. Subsequently, the confined cross-linking within the initial membrane leads to a denser PA layer (compared with pristine PA (1%)) that exhibits permeance up to 19.86 L m-2 h-1 bar-1 with a 98.2% rejection of Na2SO4. This work first reports a strategy for the bidirectional regulation of the PA active layer toward looser or denser morphological evolution, and highlights the considerable promise of the LDH/PA composite membrane for versatile separation tasks in water treatment.

Polyamide thin-film composite (PA-TFC) membranes have revolutionized the water treatment sector, particularly in desalination and wastewater reuse. However, overcoming the "trade-off" effect between membrane permeance and selectivity remains a major challenge. In this work, two-dimensional porous layered double oxides (LDO) were incorporated as an interlayer during interfacial polymerization (IP), thus yielding thin-film nanocomposite membranes designed for fast desalination. The micro-mesoporous structure of LDO facilitated the transport of water by creating additional pathways. More significantly, systematic modulation of the LDO loading resulted in membranes featuring two distinct morphological structures. At a lower LDO loading, the embedded LDO led to a polyamide membrane with wrinkled surface morphology, exhibiting a Na2SO4 rejection rate of 96.3% and a permeation flux of 22.4 L m-2 h-1 bar-1. At a higher LDO loading, the horizontally aligned LDO "nano-bricks" hindered piperazine (PIP) transport via a "tortuous effect", thereby producing a thinner and more loosely structured PA layer achieving a water permeance of 24.7 L m-2 h-1 bar-1, coupled with a Na2SO4 rejection of 97.1%. Besides, the membrane showed enhanced fouling resistance and mechanical robustness. This study demonstrates a simple approach to constructing high-performance PA membranes and provides fundamental insights into nanomaterial-mediated interfacial polymerization reactions.

Sensitive and selective detection of contaminants is crucial for environmental protection.As promising materials,engineered metal-organic frameworks with unique physicochemical properties of composites and framework modularity,large surface area,tunable pore sizes,and multi-functionality have shown significant advances in environmental determinations.This review provides an overview of the key sensing parameters in analytical chemistry and outlines the synthesis principles as well as research progress of metal-organic framework-based sensory materials in pollutant detection.Where engineered metal-organic frameworks serve as an integral component of the achieved function,highlighting the typical regulation strategies that involve tuning active sites,ligand functionalization,pyrolysis,and modification of functional compounds,among others,to achieve performance improvement.Following,we present the unique properties of engineered metal-organic frameworks that can be harnessed to develop different types of sensing systems based on the sensing mechanisms of spectrometry,luminescence,electrical transduction,and others to achieve highly sensitive and selective detection of different contaminants.Finally,the current challenges and perspectives on the development and exploration of advanced metal-organic frameworks for sensing are discussed.

The rapid and efficient separation of nanoscale targets in liquid matrices presents a critical yet formidable challenge. Polyamide (PA) membranes, while recognized as the benchmark for industrial-scale nanoscale separation, face ongoing limitations in performance optimization. Although advances in nanomaterials have enabled breakthroughs in PA membrane performance, scalable production remains hindered by integration challenges. Here, we present a scalable strategy to fabricate ultra-thin (<10 nm) nanofiltration membranes by constructing a layered double hydroxide (LDH) nanoplate-enhanced piperazine (PIP) intermediate layer via interfacial polymerization (IP) with trimesoyl chloride. Hydrogen-bond networks between PIP and LDH, combined with ordered water structures induced by LDH hydroxyl groups, restricted PIP diffusion, thus yielding ultrathin membranes with high ionization. Moreover, the rough LDH intermediate layer promoted a rougher membrane surface, enhancing the effective filtration area and permeability. The optimized membranes achieved a pure water permeance of 89.6 +/- 3.5 L m(-2) h(-1) bar(-1) and a Na2SO4 rejection rate of 95.7%, achieving one of the best-reported levels. Leveraging the accessibility of LDH colloids and the scalable fabrication process, this strategy enables the production of large-area membranes via spraying and IP, making it highly promising for purifying and recovering antibiotics.

Chemical upcycling of plastic waste into value-added feedstocks holds great promise for advancing the circular economy, while confronting formidable challenges. Herein, we report a cost-effective catalyst MgAl-layered double oxide (MgAl-LDO) for upcycling polystyrene (PS) into liquid fuel substitute components with rich styrene under solvent- and H2-free conditions. The operando characterizations and theoretical simulations demonstrate that the MgAl-LDO, featuring rich basic sites (Mg─O), is favorable for efficient activation of C─H bonds and selective cleavage of C(sp3)-C(sp3) bonds. In particular, MgO in MgAl-LDO affords a low barrier for the rate-determining step for the formation of styrene while simultaneously suppressing the side reaction of further hydrogenation. As a result, the MgAl-LDO achieves a liquid fuel yield of 59.5% with a styrene selectivity of 70.9% at 280°C. Further, the obtained styrene monomer was copolymerized with methyl methacrylate (MMA) to prepare high value-added MMA-styrene copolymer, which offers pivotal insights into advanced chemical upcycling strategies, facilitating the transition to a sustainable plastics economy and the reduction of environmental impacts.

Abstract Chemical recycling offers an efficient pathway for upcycling waste plastics into high‐value resources, although it is still facing challenges. Herein, we demonstrate microwave‐assisted synergistic conversion of waste plastics and CO 2 into syngas over ZnFe 2 O 4 /SiC, which undergoes reconstruction into ZnO–Fe 3 C/SiC. SiC converts microwave energy into heat and transfers it directly to the catalytic layer, enabling polyethylene to generate hydrogen and carbon species. Fe 3 C acts as a dynamic carbon reservoir for capturing and transferring carbon species. Meanwhile, CO 2 dissociates on the ZnO surface to form CO and oxygen species. The oxygen species further combine with the carbon species provided by Fe 3 C to generate additional CO, thereby achieving in situ carbon elimination and catalyst self‐stabilization. This work presents a microwave‐assisted strategy that couples plastic valorization with CO 2 utilization, offering new insights into sustainable syngas production from carbon‐containing waste.

The energy crisis, along with environmental deterioration and climate change caused by fossil fuel combustion, has propelled scientific and technological developments for versatile renewable energy applications. As a green technology, photocatalysis enables the conversion of abundant solar energy into useful chemical energy, in which advanced photocatalysts play a crucial role. Among various photocatalysts, layered double hydroxides (LDHs), a class of two-dimensional (2D) materials, and their derivatives, such as mixed metal oxide (MMO) and spinel, have attracted considerable attention in solar energy conversion. This review summarizes the recent achievements of LDHs and their derivatives used in photocatalysis. First, the LDHs, MMO, and spinel photocatalysts are briefly introduced. Next, the advanced strategies of structure modulation for photocatalytic properties are systematically elaborated. Then, the photocatalytic performance of LDHs and their derivatives is described concerning their applications in photocatalysis, including water splitting, CO2 reduction, and N2 fixation. Finally, the challenges and opportunities for the future development of this fast-growing area are presented and thoroughly discussed.

Aqueous secondary batteries (ASBs) employing CO3 2- electrolyte are rare-studied but desirable technologies providing eco-friendly, safe, and cost-effective energy storage. Herein, novel ASBs based on CO3 2- anion shuttling between CoNiCu-C-LDH/CNT and Cu2CO3(OH)2/CNT in alkaline electrolyte (AACBs) are reported for the first time. During charge/discharge, Co/Ni metals in laminates of cathode subjected to oxidation/reduction while CO3 2- is reversibly inserted/extracted within interlayers, juxtaposed with CO3 2- released/consolidated on anode. Integrated into pouch battery, highly reversible electrochemical properties were discovered, powering 2 white LEDs with two AACBs in tandem. The initial capacity at 200 mA g-1 was ∼130 mAh g-1 with stable retention of ∼101 mAh g-1 after 200 cycles. At 400/800 mA g-1, capacities of ∼94/∼67 mA g-1 were marked respectively. The AACBs hold lowest energy cost, enabling massive production. The excellent CO3 2- storage can also be reached via Cl- transporting. The findings highlight potential of LDHs on sustainable energy storage/conversion, identifying promising development prospects to new class of aqueous anion batteries (AABs).

ABSTRACT Chemical upcycling of plastic wastes into high‐value‐added products presents a promising pathway toward achieving a circular economy and mitigating environmental issues, yet huge challenges remain. Drawing inspiration from hydrolases, this study proposes the construction of F‐Zn sites in layered double hydroxides (LDHs) for the efficient photothermal catalytic upcycling of polyethylene terephthalate (PET) waste into bis(2‐hydroxyethyl) terephthalate (BHET). Light irradiation induces dynamically varied Zn active sites, which mimic the metal centers of hydrolases and thereby facilitate the nucleophilic addition–elimination reaction at the carbonyl moieties of PET. Simultaneously, the high electronegativity of F intensifies its interaction with the hydroxyl groups of ethylene glycol. This mimics the hydrogen‐bonding interactions mediated by the amino acid residues of hydrolases, promoting the nucleophilic attack on the PET. The synergistic effect of F–Zn configuration thereby effectively reduces the reaction energy barrier for PET glycolysis, enabling complete PET conversion under 160°C with a BHET yield of ∼80%. This study presents the integration of a bioinspired site‐design strategy into a photothermal catalytic platform as a promising strategy for plastic waste upcycling.

Energy dilemmas and environmental degradation have emerged as interconnected challenges that command extensive global attention. Herein, we report an integrated strategy through integrating photocatalysis and biosynthesis for producing single-cell protein (SCP), utilizing carbon dioxide (CO2) as the carbon source. First, Eu-doped NiAl-layered double hydroxides (Eu-NiAl-LDHs) were rationally designed via orbital coupling engineering for photocatalytic-driven CO2 reduction, enabling the effective synthesis of syngas (CO and H-2) with tunable composition. Moving downstream to the biosynthetic phase, Hydrogenophaga pseudoflava Z-1107 was strategically utilized to transform the precursor syngas into SCP, with a cell dry weight of 566 mg L-1. This work thus demonstrates a potential route toward a carbon-negative solution of upgrading CO2.

The widespread use of plastics has led to significant environmental pollution, but microplastics (MPs) have had a noteworthy impact in this regard and serve as carriers for various toxic pharmaceuticals. Therefore, there is a need to design a water treatment process capable of simultaneously removing MPs and pharmaceuticals. In this study, a novel photocatalytic membrane, composed of a binary C3N4/Bi12O17Cl2 (CN/BOC) heterojunction immobilized on a polyacrylonitrile (PAN) membrane via electrospinning, is developed to address this issue. Comprehensive characterizations confirm the formation of a heterojunction structure that optimizes charge separation and prolongs electron lifetime. The CN/BOC/PAN photocatalytic membrane demonstrates 100 % removal efficiency for 19 out of 20 types of mixed pharmaceuticals within 180 min. Additionally, the membrane converts polylactic acid (PLA) into value-added organic acids, thereby offering a sustainable approach to plastic upcycling. The highest occupied molecular orbital (HOMO), lowest unoccupied molecular orbital (LUMO), and Fukui index are employed to identify the active sites for carbamazepine (CBZ) and PLA degradation. This study provides new insights into the photocatalytic removal of pharmaceuticals and MPs, highlighting the potential for remediating water-borne contaminants.

Chemical upcycling of waste plastics offers a promising way toward achieving a circular economy and alleviating environmental pollution but remains a huge challenge. Inspired by hydrolase enzymes and aiming to overcome their intrinsic limitations, we put forward a design principle for an innovative nanozyme featuring asymmetric metal sites. This nanozyme functions as photocatalyst, enabling sustainable valorization of polyester plastics. As a proof of concept, an asymmetric ligand substitution strategy is developed to construct metal-organic frameworks (MOFs) that are defective MIL-101(Fe) (D-MIL-101) with asymmetric Fe3-δ/Fe3+ (0< δ <1) sites. The differential electronic configurations inherent to adjacent Fe3-δ/Fe3+ sites endow a high photocatalytic activity for the valorization of polyester plastic. Accordingly, the ester bonds of polyesters can be preferentially cleaved, contributing to the low energy barrier of upcycling plastics. As a result, the D-MIL-101 achieves a high monomer yield with terephthalic acid (TPA) of ∼93.9% and ethylene glycol (EG) of ∼87.1% for photocatalytic valorization of poly (ethylene terephthalate) (PET), beyond the efficiency of natural enzymes and state-of-the-art photocatalysts. In addition, such a D-MIL-101 is demonstrated to be feasible for the valorization of various real-world polyester plastic wastes in a flow photocatalysis system.

Upcycling carbon dioxide (CO 2 ) into long-chain compounds has attracted considerable attention with respect to mitigating environmental problems and obtaining value-added feedstocks, but remains a great challenge. Herein, we report a tandem photocatalysis-biosynthesis strategy for efficient CO 2 reduction to energy-rich sucrose or α-farnesene. Firstly, photocatalytic reduction of CO 2 to CH 4 was optimized over the transitional metal doped ZnO (M−ZnO). The as-prepared Ni−ZnO preferentially reduces CO 2 to CH 4 with a production rate of 1539.1 μmol g −1  h −1 and a selectivity of 90 %, owing to the unique interface structure (Zn δ + −O−Ni β + ). Subsequently, Methylomicrobium buryatense 5GB1C was genetically engineered to produce sucrose or α-farnesene using photocatalytically-obtained CH 4 as the sole carbon source, with a titer of 96.3 and 43.9 mg L −1 , respectively. This study provides a green, low-energy pathway for the synthesis of long-chain compounds from CO 2 as the carbon source, which sheds new light on tackling long-term energy demands and sustainable CO 2 upcycling.

Solar-driven photocatalytic CO2 reduction receives intensive attention while facing the challenge of achieving a single product with high conversion efficiency. Herein, we report a feasible strategy for regulating isolated dualmetal sites on semiconductive metal-organic frameworks (MOFs) for efficient CO2 photoreduction. The atomically isolated CuM dual-metal (M = Co, Ni, Fe) sites on two-dimensional CuM-THQ (THQ = tetrahydroxyquinone) with high activity are obtained. Impressively, the CuCo dual-metal sites present a CO production rate of 1626 mu mol g- 1 h- 1 and near 100 % selectivity under visible-light irradiation. The presence of Co sites induces the metal-to-metal charge transfer (MMCT) process in CuM dual-metal sites, enabling the extension of charge separation distance and thereby accelerating reacting kinetics. Moreover, the declined 3d-orbital occupancy on CuCo dual-metal sites facilitates CO2 adsorption and reduces the energy barrier of the rate-determining step (*CO2 to *COOH). Meanwhile, the isolated Cu sites provide a weak desorption of *CO intermediates to produce exclusive CO. As a result, the synergist effect of isolated dual-metal sites on MOFs contributes to the high performance of CO2-to-CO.

Chemical upcycling of plastic wastes into valuable chemical feedstocks and simultaneous mitigation of environmental deterioration are fascinating but remain extremely challenging. Herein, we report microwave-assisted valorization of plastic wastes into carbon nanotubes (CNTs) and hydrogen (H2) over heterojunction-structured mixed metal oxides. Specifically, the CoNiFe-based layered triple oxides (LTO) arrayed on Ni-foam (CoNiFe-LTO@foam) were constructed. The special heterojunction of the LTO endows high dielectric loss, facilitating efficient conversion of absorbed microwave energy into thermal energy. Most importantly, the synergistic effect of the multiple transition metal sites boosts the cleavage of carbon chains and dehydrogenation, thereby accelerating the reaction kinetics. As a result, the CoNiFe-LTO@foam achieves an H2 selectivity of ∼95 vol % with the yield of ∼69 mmol·gplastic-1 for upcycling polyethylene in 25 cycles of measurement. Simultaneously, the CNTs attain a yield of ∼35%, which can be used for aqueous chloride-ion batteries. Additionally, the CoNiFe-LTO@foam enables facile recovery of CNTs and prevents the loss of catalytic sites, facilitating upcycling of various real-world plastic wastes. Our work thus highlights the innovations of an advanced catalytic system for forming a closed loop of plastic C/H and achieving the ultimate goal of a carbon-neutral society.

Photocatalytic conversion of carbon dioxide (CO2) into methane (CH4) offer a promising solution to mitigate the energy crisis while reducing greenhouse gas emissions. However, designing semiconductor photocatalysts capable of absorbing visible light and selectively convert CO2 to CH4 remains a significant challenge. In this work, we systematically investigated a series of TM-X@BN single-atom catalysts (SACs) (X = C, O, S), focusing on precise band gap and band edge tuning to optimize their performance for photocatalytic CO2 reduction. Density functional theory (DFT) calculations show that single TM doping effectively reduces the band gap of BN. Further introduction of O/S atoms into TM@BN SACs increases the band gap and shifts the band edges towards more negative potentials, while C doping allows for fine-tuning of the band gap. As the number of C atoms increases, the band gap of TM-nC@BN(n = 1, 2, 3) gradually decreases, and the band edge position contracts uniformly. This intriguing phenomenon can be attributed to the varying bond strengths between the metal and surrounding atoms: the stronger the bonding, the narrower the band gap. These findings enable precise tuning of the band gap in TM-doped BN materials. Based on these insights, we successfully designed eight potential catalysts for CO2RR to produce CH4 and systematically compared their activity and selectivity. Among them, Fe-C@BN exhibited exceptional activity and selectivity. Experimental results demonstrate that under 300 W xenon lamp irradiation (320 < lambda < 780 nm), Fe-C@BN achieved a CH4 yield of 1319.6 mu mol g(-1) h(-1) with a selectivity of 89.7 %, confirming its promising performance. This work provides a theoretical perspective from the perspective of band gap regulation for the design of photocatalysts for CO2RR.

The extensive utilization of plastics leads to serious environmental concerns due to their persistence and accumulation in the world. In this study, metal doping engineering over layered double hydroxides (LDHs) is carried out, which is applied to improve photocatalytic performance for upcycling polyethylene terephthalate (PET) into terephthalic acid (TPA) and ethylene glycol (EG). A series of M/ZnCr-LDHs (M = Ag, Cu, Mo, Ti) is synthesized by co-precipitation synthesis and subsequent solution plasma treatment. The efficient incorporation of M sites without obviously modifying the LDHs structure is achieved by solution plasma treatment. The investigation reveals that the presence of Ti sites in Ti/ZnCr-LDHs enhances light absorption, facilitates charge carrier separation, and improves the surface catalytic activity under light irradiation. As a result, Ti/ZnCr-LDHs display the best performance, achieving complete PET conversion and maximum EG and TPA production of 1215 and 3200 mg gcat-1 h-1, respectively. This work not only provides a universal way for doping engineering over photocatalysts but also provides insight into upcycling plastic waste.

Plastic products bring convenience to various aspects of the daily lives due to their lightweight, durability and versatility, but the massive accumulation of post-consumer plastic waste is posing significant environmental challenges. Catalytic methods can effectively convert plastic waste into value-added feedstocks, with catalysts playing an important role in regulating the yield and selectivity of products. This review explores the latest advancements in advanced catalysts applied in thermal catalysis, microwave-assisted catalysis, photocatalysis, electrocatalysis, and enzymatic catalysis reaction systems for the chemical recycling of plastic waste into valuable feedstocks. Specifically, the pathways and mechanisms involved in the plastics recycling process are analyzed and presented, and the strengths and weaknesses of various catalysts employed across different reaction systems are described. In addition, the structure-function relationship of these catalysts is discussed. Herein, it is provided insights into the design of novel catalysts applied for the chemical recycling of plastic waste and outline challenges and future opportunities in terms of developing advanced catalysts to tackle the “white pollution” crisis.

Plastic wastes impose a significant environmental burden, yet chemically recycling them into valuable feedstocks remains presenting huge challenges. Herein, an energy‐saving microwave‐assisted catalysis system is reported via interfacial engineering of the catalyst layer on the microwave absorber for selective valorization of plastic wastes into hydrogen (H 2 ) and carbon nanotubes (CNTs). As proof of concept, a NiFe alloy layer coated on a microporous SiC foam (SiC@NiFe) is fabricated. The unique architecture enables directional thermal transfer from SiC to NiFe, minimizing energy losses from disordered thermal dissipation while preventing undesired contact of plastic‐SiC, thereby enhancing energy utilization efficiency and suppressing side reactions, respectively. Moreover, the increased inside pressure generated during plastic decomposition creates a favorable pressure gradient, driving efficient mass transfer into the microporous foam. Accordingly, the confined intermediates undergo sufficient contact with the NiFe catalytic layer. The resultant SiC@NiFe delivered H 2 yield of 67 mmol g plastic −1 with selectivity of 96 vol.% at 450 °C in upcycling of low‐density polyethylene (LDPE). This work presents a viable strategy for plastic waste valorization with the advantages of high efficiency and energy‐saving operation, provides valuable perspectives on addressing white pollution within the framework of the circular economy.