Current Issue

2025, Volume 10,  Issue 2

Display Method:
Viewpoint
Abstract:
Carbon Capture, Utilization, and Storage (CCUS) is a crucial technology for achieving carbon neutrality, but it faces significant challenges. Despite substantial investments and policy support, CCUS projects have underperformed due to technical difficulties, high costs, and controversies surrounding the fossil fuel industry's involvement. The effectiveness and feasibility of CCUS in reducing carbon emissions remain uncertain. This viewpoint provides a comprehensive analysis of the current state of CCUS technology, examining its potential to reduce carbon emissions, the challenges hindering its deployment, and the strategies needed to overcome these barriers. We discuss the need for a combinatorial approach to unlock CCUS's full potential, and also emphasize the importance of selecting optimal CO2 utilization pathways to maximize economic benefits and CO2 absorption. Although CCUS faces technical, economic, and social barriers, it can still play a valuable role in mitigating emissions from hard-to-abate sectors when supported by comprehensive strategies and collaborative efforts among governments, industries, and research institutions. By addressing these challenges and investing in innovation, CCUS can contribute to achieving carbon neutrality and building a sustainable, low-carbon future.
Review Article
Abstract:
Membrane technology holds significant potential for augmenting or partially substituting conventional separation techniques, such as heat-driven distillation, thereby reducing energy consumption. Organic solvent nanofiltration represents an advanced membrane separation technology capable of discerning molecules within a molecular weight range of approximately 100-1000 Da in organic solvents, offering low energy requirements and minimal carbon footprints. Molecular separation in non-polar solvent system, such as toluene, n-hexane, and n-heptane, has gained paramount importance due to their extensive use in the pharmaceutical, biochemical, and petrochemical industries. In this review, we presented recent advancements in membrane materials, membrane fabrication techniques and their promising applications for separation in non-polar solvent system, encompassing hydrocarbon separation, bioactive molecule purification and organic solvent recovery. Furthermore, this review highlighted the challenges and opportunities associated with membrane scale-up strategies and the direct translation of this promising technology into industrial applications.
Abstract:
Electrochemical nitrogen transformation techniques represent a burgeoning avenue for nitrogen pollutant remediation and synthesizing valuable nitrogenous products from atmospheric nitrogen. Intermetallic compounds (IMCs) nanocrystals, featured with unique geometric, electronic and functional properties, have emerged as promising candidates. The review discusses various synthesis approaches for IMCs, including thermal annealing, wet chemical synthesis, electrochemical synthesis, and other emerging methods, analyzing their advantages and limitations. Then we summarized the recent advances of IMCs in electrocatalytic nitrogen transformation reactions, such as nitrate reduction reaction, nitric oxide reduction reaction, nitrogen reduction reaction, and hydrazine oxidation reaction. Despite significant progress, challenges remain in the field, particularly in adopting more refined strategies to improve catalyst performance and stability. This review aims to comprehensively understand the structural properties of IMCs and their structure-performance relationship, guiding the development of more efficient and stable catalysts for future nitrogen electrochemistry.
Abstract:
In recent years, studies focusing on the conversion of renewable lignin-derived oxygenates (LDOs) have emphasized their potential as alternatives to fossil-based products. However, LDOs, existing as complex aromatic mixtures with diverse oxygen-containing functional groups, pose a challenge as they cannot be easily separated via distillation for direct utilization. A promising solution to this challenge lies in the efficient removal of oxygen-containing functional groups from LDOs through hydrodeoxygenation (HDO), aiming to yield biomass products with singular components. However, the high dissociation energy of the carbon-oxygen bond, coupled with its similarity to the hydrogenation energy of the benzene ring, creates a competition between deoxygenation and benzene ring hydrogenation. Considering hydrogen consumption and lignin properties, the preference is directed towards generating aromatic hydrocarbons rather than saturated components. Thus, the goal is to selectively remove oxygen-containing functional groups while preserving the benzene ring structure. Studies on LDOs conversion have indicated that the design of active components and optimization of reaction conditions play pivotal roles in achieving selective deoxygenation, but a summary of the correlation between these factors and the reaction mechanism is lacking. This review addresses this gap in knowledge by firstly summarizing the various reaction pathways for HDO of LDOs. It explores the impact of catalyst design strategies, including morphology modulation, elemental doping, and surface modification, on the adsorption-desorption dynamics between reactants and catalysts. Secondly, we delve into the application of advanced techniques such as spectroscopic techniques and computational modeling, aiding in uncovering the true active sites in HDO reactions and understanding the interaction of reactive reactants with catalyst surface-interfaces. Additionally, fundamental insights into selective deoxygenation obtained through these techniques are highlighted. Finally, we outline the challenges that lie ahead in the design of highly active and selective HDO catalysts. These challenges include the development of detection tools for reactive species with high activity at low concentrations, the study of reaction medium-catalyst interactions, and the development of theoretical models that more closely approximate real reaction situations. Addressing these challenges will pave the way for the development of efficient and selective HDO catalysts, thus advancing the field of renewable LDOs conversion.
Abstract:
With the increase of energy consumption, the shortage of fossil resource, and the aggravation of environmental pollution, the development of cost-effective and environmental friendly bio-based energy storage devices has become an urgent need. As the second most abundant natural polymer found in nature, lignin is mainly produced as the by-product of paper pulping and bio-refining industries. It possesses several inherent advantages, such as low-cost, high carbon content, abundant functional groups, and bio-renewable, making it an attractive candidate for the rechargeable battery material. Consequently, there has been a surge of research interest in utilizing lignin or lignin-based carbon materials as the components of lithium-ion (LIBs) or sodium-ion batteries (SIBs), including the electrode, binder, separator, and electrolyte. This review provides a comprehensive overview on the research progress of lignin-derived materials used in LIBs/SIBs, especially the application of lignin-based carbons as the anodes of LIBs/SIBs. The preparation methods and properties of lignin-derived materials with different dimensions are systemically discussed, which emphasizes on the relationship between the chemical/physical structures of lignin-derived materials and the performances of LIBs/SIBs. The current challenges and future prospects of lignin-derived materials in energy storage devices are also proposed.
Research Paper
Abstract:
Thick electrodes can reduce the ratio of inactive constituents in a holistic energy storage system while improving energy and power densities. Unfortunately, traditional slurry-casting electrodes induce high-tortuous ionic diffusion routes that directly depress the capacitance with a thickening design. To overcome this, a novel 3D low-tortuosity, self-supporting, wood-structured ultrathick electrode (NiMoN@WC, a thickness of ∼1400 μm) with hierarchical porosity and artificial array-distributed small holes was constructed via anchoring bimetallic nitrides into the monolithic wood carbons. Accompanying the embedded NiMoN nanoclusters with well-designed geometric and electronic structure, the vertically low-tortuous channels, enlarged specific surface area and pore volume, superhydrophilic interface, and excellent charge conductivities, a superior capacitance of NiMoN@WC thick electrodes (∼5350 mF cm-2 and 184.5 F g-1) is achieved without the structural deformation. In especial, monolithic wood carbons with gradient porous network not only function as the high-flux matrices to ameliorate the NiMoN loading via cell wall engineering but also allow fully-exposed electroactive substance and efficient current collection, thereby deliver an acceptable rate capability over 75% retention even at a high sweep rate of 20 mA cm-2. Additionally, an asymmetric NiMoN@WC//WC supercapacitor with an available working voltage of 1.0-1.8 V is assembled to demonstrate a maximum energy density of ∼2.04 mWh cm-2 (17.4 Wh kg-1) at a power density of 1620 mW cm-2, along with a decent long-term lifespan over 10,000 charging-discharging cycles. As a guideline, the rational design of wood ultrathick electrode with nanostructured transition metal nitrides sketch a promising blueprint for alleviating global energy scarcity while expanding carbon-neutral technologies.
Abstract:
TiNb2O7 has been emerged as one of the most promising electrode materials for high-energy lithium-ion batteries. However, limited by the slow electron/ion transport kinetics, and insufficient active sites in the bulk structure, the TiNb2O7 electrode still suffers from unsatisfactory lithium storage performance. Herein, we demonstrate a spatially confined strategy toward a novel TiNb2O7-NMC/MXene composite through a triblock copolymer-directed one-pot solvothermal route, where TiNb2O7 quantum dots with a particle size of 2-3 nm are evenly embedded into N-doped mesoporous carbon (NMC) and Ti3C2TX MXene. Impressively, the as-prepared TiNb2O7-NMC/MXene anode exhibits a high reversible capacity (486.2 mAh g-1 at 0.1 A g-1 after 100 cycles) and long cycle lifespan (363.4 mAh g-1 at ss1 A g-1 after 500 cycles). Both experimental and theorical results further demonstrate that such a superior lithium storage performance is mainly ascribed to the synergistic effect among 0D TiNb2O7 quantum dots, 2D Ti3C2TX MXene nanosheets, and N-doped mesoporous carbon. The strategy presented also opens up new horizon for space-confined preparation of high-performance electrode materials.
Abstract:
Essentially clearing the structure-activity relationship between iron carbide catalysts involving multiple active centers to understand the reaction mechanism of CO hydrogenation conversion process is still a great challenge. Here, two main micro-environment factors, namely electronic properties and geometrical effects were found to have an integrated effect on the mechanism of CO hydrogenation conversion, involving active sites on multiple crystal phases. The Bader charge of the surface Fe atoms on the active sites had a guiding effect on the CO activation pathway, while the spatial configuration of the active sites greatly affected the energy barriers of CO activation. Although the defective surfaces were more conducive to CO activation, the defective sites were not the only sites to dissociate CO, as CO always tended to dissociate in a wider area. This synergistic effect of the micro-environment also occurred during the CO conversion process. Surface C atoms on relatively flat configurations were more likely to form methane, while the electronic properties of the active sites could effectively describe the C-C coupling process, as well as distinguish the coupling mechanisms.
Abstract:
Sodium-ion batteries (SIBs) hold great promise for large-scale energy storage in the post-lithium-ion battery era due to their high rate performance and long lifespan, although their sluggish Na+ transformation kinetics still require improvement. Encouraged by the excellent electrochemical performance of titanium-based anode materials, here, we present a novel titanium vanadate@carbon (TVO@C) material as anode for SIBs. Our TVO@C material is synthesized via a facile coprecipitation method, with the following annealing process in an acetylene atomosphere. The opened ion channel and the oxygen vacancies within TVO@C facilitate the diffusion of Na+ ions, reducing their diffusion barrier. Thus, an ultrahigh rate of 100 A g-1 and long life of 10,000 cycles have been achieved. Furthermore, the TVO@C electrode exhibits stable performance, not only at room temperature, but also at temperatures as low as -20 ℃. The TVO@CNa3V2(PO4)3@C full cells have also achieved stable discharge/charge for 500 cycles. It is believed that this strategy provides new insight into the development of advanced electrodes and provides a new opportunity for constructing novel high rate electrodes.
Abstract:
Aqueous zinc-ion batteries (AZIBs) present a promising option for next-generation batteries given their high safety, eco-friendliness, and resource sustainability. Nonetheless, the practical application of zinc anodes is hindered by inevitable parasitic reactions and dendrite growth. Here, zinc alloy layers (i.e., ZnCo and ZnFe alloys) were rationally constructed on the zinc surface by chemical displacement reactions. The alloying process exposes more (002) planes of the ZnCo anode to guide the preferential and dendrite-free zinc deposition. Furthermore, the ZnCo alloy layer not only effectively inhibits water-induced side reactions but also accelerates electrode kinetics, enabling highly reversible zinc plating/stripping. As a result, the ZnCo anode achieves a Coulombic efficiency of 99.2% over 1300 cycles, and the ZnCo symmetric cell exhibits a long cycle life of over 2000 h at 4.4 mA cm-2. Importantly, the ZnCo//NH4V4O10 full cell retains a high discharge capacity of 218.4 mAh g-1 after 800 cycles. Meanwhile, the ZnFe-based symmetric cell also displays excellent cycling stability over 2500 h at 1.77 mA cm-2. This strategy provides a facile anode modification approach toward high-performance AZIBs.
Abstract:
Organic nanophotocatalysts are promising candidates for solar fuels production, but they still face the challenge of unfavorable geminate recombination due to the limited exciton diffusion lengths. Here, we introduce a binary nanophotocatalyst fabricated by blending two polymers, PS-PEG5 (PS) and PBT-PEG5 (PBT), with matched absorption and emission spectra, enabling a Förster resonance energy transfer (FRET) process for enhanced photocatalysis. These heterostructure nanophotocatalysts are processed using a facile and scalable flash nanoprecipitation (FNP) technique with precious kinetic control over binary nanoparticle formation. The resulting nanoparticles exhibit an exceptional photocatalytic hydrogen evolution rate up to 65 mmol g-1 h-1, 2.5 times higher than that single component nanoparticles. Characterizations through fluorescence spectra and transient absorption spectra confirm the hetero-energy transfer within the binary nanoparticles, which prolongs the excited-state lifetime and extends the namely “effective exciton diffusion length”. Our finding opens new avenues for designing efficient organic photocatalysts by improving exciton migration.
Abstract:
Garnet Li7La3Zr2O12 (LLZO) electrolytes have been recognized as a promising candidate to replace liquid/molten-state electrolytes in battery applications due to their exceptional performance, particularly Ga-doped LLZO (LLZGO), which exhibits high ionic conductivity. However, the limited size of the Li+ transport bottleneck restricts its high-current discharging performance. The present study focuses on the synthesis of Ga3+ and Ba2+ co-doped LLZO (LLZGBO) and investigates the influence of doping contents on the morphology, crystal structure, Li+ transport bottleneck size, and ionic conductivity. In particular, Ga0.32Ba0.15 exhibits the highest ionic conductivity (6.11E-2 S cm-1 at 550 ℃) in comparison with other compositions, which can be attributed to its higher-energy morphology, larger bottleneck and unique Li+ transport channel. In addition to Ba2+, Sr2+ and Ca2+ have been co-doped with Ga3+ into LLZO, respectively, to study the effect of doping ion radius on crystal structures and the properties of electrolytes. The characterization results demonstrate that the easier Li+ transport and higher ionic conductivity can be obtained when the electrolyte is doped with larger-radius ions. As a result, the assembled thermal battery with Ga0.32Ba0.15-LLZO electrolyte exhibits a remarkable voltage platform of 1.81 V and a high specific capacity of 455.65 mA h g-1 at an elevated temperature of 525 ℃. The discharge specific capacity of the thermal cell at 500 mA amounts to 63% of that at 100 mA, showcasing exceptional high-current discharging performance. When assembled as prototypes with fourteen single cells connected in series, the thermal batteries deliver an activation time of 38 ms and a discharge time of 32 s with the current density of 100 mA cm-2. These findings suggest that Ga, Ba co-doped LLZO solid-state electrolytes with high ionic conductivities holds great potential for high-capacity, quick-initiating and high-current discharging thermal batteries.
Abstract:
Iron-chromium flow batteries (ICRFBs) have emerged as an ideal large-scale energy storage device with broad application prospects in recent years. Enhancement of the Cr3+/Cr2+ redox reaction activity and inhibition of the hydrogen evolution side reaction (HER) are essential for the development of ICRFBs and require a novel catalyst design. However, elucidating the underlying mechanisms for modulating catalyst behaviors remains an unresolved challenge. Here, we show a novel precisely controlled preparation of a novel thermal-treated carbon cloth electrode with a uniform deposit of low-cost indium catalyst particles. The density functional theory analysis reveals the In catalyst has a significant adsorption effect on the reactants and improves the redox reaction activity of Cr3+/Cr2+. Moreover, H+ is more easily absorbed on the surface of the catalyst with a high migration energy barrier, thereby inhibiting the occurrence of HER. The assembled ICRFBs have an average energy efficiency of 83.91% at 140 mA cm-2, and this method minimizes the electrodeposition process and cleans the last obstacle for industry long cycle operation requirements. The ICRFBs exhibit exceptional long-term stability with an energy efficiency decay rate of 0.011% per cycle at 1000 cycles, the lowest ICRFBs reported so far. Therefore, this study provides a promising strategy for developing ICRFBs with low costs and long cycle life.
Abstract:
Converting CO2 and water into valuable chemicals like plant do is considered a promising approach to address both environmental and energy issues. Taking inspiration from the structures of natural leaves, we designed and synthesized a novel copper-coordinated covalent triazine framework (CuCTF) supported by silicon nanowire arrays on wafer chip. This marks the first-ever application of such a hybrid material in the photoelectrocatalytic reduction of CO2 under mild conditions. The Si@CuCTF6 heterojunction has exhibited exceptional selectivity of 95.6% towards multicarbon products (C2+) and apparent quantum efficiency (AQE) of 0.89% for carbon-based products. The active sites of the catalysts are derived from the nitrogen atoms of unique triazine ring structure in the ordered porous framework and the abundant Cu-N coordination sites with bipyridine units. Furthermore, through DFT calculations and operando FTIR spectra analysis, we proposed a comprehensive mechanism for the photoelectrocatalytic CO2 reduction, confirming the existence of key intermediate species such as *CO2-, *=C=O, *CHO and *CO-CHO etc. This work not only provides a new way to mimic photosynthesis of plant leaves but also gives a new opportunity to enter this research field in the future.
Abstract:
The mainstream silver recovery has problems such as resource waste, weak silver selectivity, and complicated operation. Here, self-propelled magnetic enhanced capture hydrogel (magnetic NbFeB/MXene/GO, MNMGH) was prepared by self-crosslinking encapsulation method. MNMGH achieved high selectivity (Kd = 23.31 mL/g) in the acidic range, and exhibited ultrahigh silver recovery capacity (1604.8 mg/g), which greatly improved by 66% with the assistance of in-situ magnetic field. The recovered silver crystals could be directly physically exfoliated, without acid/base additions. The selective sieving effect of adsorption, MNMGH preferentially adsorbed Ag(I), and then selectively reduced to Ag(0), realizing dual-selective recovery. The in-situ magnetic field enhanced selective adsorption by enhancing mass transfer, reactivity of oxygen-containing functional groups. Furthermore, density function theory simulations demonstrated that the in-situ magnetic field could lower the silver reduction reaction energy barrier to enhance the selective reduction. Three-drive synergy system (reduction drive, adsorption drive and magnetic drive) achieved ultrahigh silver recovery performance. This study pioneered an in-situ magnetic field assisted enhancement strategy for dual-selective (adsorption/reduction) recovery of precious metal silver, which provided new idea for low-carbon recovery of noble metal from industrial waste liquids.