In Situ Construction of Zinc-Mediated Fe, N-Codoped Hollow Carbon Nanocages with Boosted Oxygen Reduction for Zn-Air Batteries.

The rational design of bifunctional oxygen electrocatalysts with unique morphology and luxuriant porous structure is significant but challenging for accelerating the reaction kinetics of rechargeable Zn-air batteries (ZABs). Herein, zinc-mediated Fe, N-codoped carbon nanocages (Zn-FeNCNs) are synthesized by pyrolyzing the polymerized iron-doped polydopamine on the surface of the ZIF-8 crystal polyhedron. The formation of the chelate between polydopamine and Fe serves as the covering layer to prevent the porous carbon nanocages from collapsing and boosts enough exposure and utilization of metal-based active species during carbonization. Furthermore, both the theoretical calculation and experimental results show that the strong interaction between polyhedron and polydopamine facilitates the evolution of high-activity zinc-modulated FeNx sites and electron transportation and then stimulates the excellent bifunctional catalytic activity for oxygen evolution reaction (OER) and oxygen reduction reaction (ORR). As expected, the Zn-air battery with Zn-FeNCNs as an air cathode displays a superior power density (256 mW cm-2) and a high specific capacity (813.3 mA h gZn-1), as well as long-term stability over 1000 h. Besides, when this catalyst is applied to the solid-state battery, the device exhibited outstanding mechanical stability and a high round-trip efficiency under different bending angles.

Integrated Ink Printing Paper Based Self-Powered Electrochemical Multimodal Biosensing (IFP-Multi ) with ChatGPT-Bioelectronic Interface for Personalized Healthcare Management.

Personalized healthcare management is an emerging field that requires the development of environment-friendly, integrated, and electrochemical multimodal devices. In this study, the concept of integrated paper-based biosensors (IFP-Multi ) for personalized healthcare management is introduced. By leveraging ink printing technology and a ChatGPT-bioelectronic interface, these biosensors offer ultrahigh areal-specific capacitance (74633 mF cm-2 ), excellent mechanical properties, and multifunctional sensing and humidity power generation capabilities. More importantly, the IFP-Multi devices have the potential to simulate deaf-mute vocalization and can be integrated into wearable sensors to detect muscle contractions and bending motions. Moreover, they also enable monitoring of physiological signals from various body parts, such as the throat, nape, elbow, wrist, and knee, and successfully record sharp and repeatable signals generated by muscle contractions. In addition, the IFP-Multi devices demonstrate self-powered handwriting sensing and moisture power generation for sweat-sensing applications. As a proof-of-concept, a GPT 3.5 model-based fine-tuning and prediction pipeline that utilizes recorded physiological signals through IFP-Multi is showcased, enabling artificial intelligence with multimodal sensing capabilities for personalized healthcare management. This work presents a promising and ecofriendly approach to developing paper-based electrochemical multimodal devices, paving the way for a new era of healthcare advancements.

Multifunctional Conductive Material Based on Intelligent Porous Paper Used in Conjunction with a Vitrimer for Electromagnetic Shielding, Sensing, Joule Heating, and Antibacterial Properties.

With the continuous improvement of living standards and advancements in science and technology, composite materials with multiple functionalities are gaining high practical value in modern society. In this paper, we present a multifunctional conductive paper-based composite with electromagnetic (EMI) shielding, sensing, Joule heating, and antimicrobial properties. The composite is prepared by growing metallic silver nanoparticles inside the cellulose paper (CP) modified with polydopamine (PDA). The resulting CP@PDA@Ag (CPPA) composite has high conductivity and EMI shielding properties. Furthermore, CPPA composites demonstrate exceptional sensing, Joule heating, and antimicrobial properties. In addition, Vitrimer, a polymer with excellent cross-linked network structure, is introduced into CPPA composites to obtain CPPA-V intelligent electromagnetic shielding materials with shape memory function. These excellent properties show that the prepared multifunctional intelligent composite has exceptional EMI shielding, sensing, Joule heating, and antibacterial and shape memory properties. In short, this multifunctional intelligent composite material has great application prospects in flexible wearable electronics.

Evaluating the effects of formation and stabilization of opal/sand aggregates with organic matter amendments.

Opal (SiO2·nH2O, amorphous silica), the by-product of alumina extraction from coal fly ash (CFA), has a strong adsorption capacity and is also an important component of clay minerals in soils. The combining of opal with sand to form artificial soils is an effective disposal strategy for large-scale CFA stockpiles and reduction of environmental risk. Nevertheless, its poor physical condition limits plant growth. Organic matter (OM) amendments have broad potential applications for water-holding and improving soil aggregation. Effects of OMs (vermicompost (VC), bagasse (BA), biochar (BC) and humic acid (HA)) on the formation, stability and pore characteristics of opal/sand aggregates were evaluated through 60-day laboratory incubation experiments. Results demonstrated that four OMs could reduce pH, with BC having the most significant effect, VC significantly increasing the electrical conductivity (EC) and TOC content of the aggregates. Except for HA, other OMs could improve the aggregates' water-holding capacity. The mean weight diameter (MWD) and percentage of >0.25 mm aggregates (R0.25) of BA-treated aggregates were the largest, and BA had the most noticeable contribution to macro-aggregate's formation. The best aggregate stability was obtained with HA treatment, meanwhile the percentage of aggregate destruction (PAD0.25) decreased with the addition of HA. After amendments, the proportion of organic functional groups increased, which favored aggregate's formation and stability; the surface pore characteristics were improved, with the porosity ranging from 70% to 75%, reaching the level of well-structured soil. Overall, the addition of VC and HA can effectively promote aggregates' formation and stabilization. This research may play a key role in converting CFA or opal into artificial soil. The combining of opal with sand to form artificial soil will not only solve the environmental problems caused by large-scale CFA stockpiles but will also enable the comprehensive utilization of siliceous materials in agriculture.

Molten salt induced formation of chitosan based carbon nanosheets decorated with CoNx for boosting rechargeable Zn-air batteries.

The earth-abundant, low-cost, and efficient oxygen electrode materials offer a potential opportunity to satisfy the large-scale production and application of metal-air batteries. Herein, a molten salt-assisted strategy is developed to anchor transition metal-based active sites via in-situ confining into porous carbon nanosheet. As a result, a chitosan-based porous nitrogen-doped nanosheet decorated with the well-defined CoNx (CoNx/CPCN) was reported. Both structural characterization and electrocatalytic mechanisms demonstrate a prominent synergetic effect between CoNx and porous nitrogen-doped carbon nanosheets forcefully accelerates the sluggish reaction kinetics of oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). Interestingly, the Zn-air batteries (ZABs) equipped with CoNx/CPCN-900 as an air electrode shows outstanding durability for 750 discharge/charge cycles, a high power density of 189.9 mW cm-2, and a high gravimetric energy density of 1018.7 mWh g-1 at 10 mA cm-2. Furthermore, the assembled all-solid cell displays exceptional flexibility and power density (122.2 mW cm-2).

Cleaning Disposal of High-Iron Bauxite Residue Using Hydrothermal Hydrogen Reduction.

The hydrothermal hydrogen reduction process for treating high-iron bauxite residue (red mud) was investigated, and the optimum conditions of alumina extraction as well as the enrichment of iron minerals were verified by experiments. Results show that the surface magnetization of Al-goethite under the function of hydrogen reduction accelerates its conversion to hematite and/or magnetite. This conversion releases the substituted Al in goethite as well as the undigested gibbsite/boehmite and further enriches the iron content in residue. After hydrothermal hydrogen reduction with H2/Red mud ratio of 0.085 mol/20 g at 270°C for 60 min, the alumina relative recovery ratio reaches 95.40% and the grade of iron (total iron in the form of iron element) in the residue can be enriched to 55.85%. Further, co-processing of the obtained iron-rich residue in the steel industry can achieve a significant reduction of red mud discharge.

Low-temperature thermal conversion of Al-substituted goethite in gibbsitic bauxite for maximum alumina extraction.

The conversion of Al-substituted goethite (Al-goethite) to hematite in gibbsitic bauxite is conducive to alumina extraction during the Bayer process and the enrichment of iron minerals in red mud. In this work, mineralogical characteristics of gibbsitic bauxite were identified by AMICS analysis, and the low-temperature thermal conversion behavior of both synthetic Al-goethite and natural Al-goethite in gibbsitic bauxite were investigated through thermal gravity analysis, phase transformation, and microstructure studies. Results show that the proportion of aluminum in Al-goethite reached 12.68% of the total aluminum content in gibbsitic bauxite. The conversion of synthetic Al-goethite to hematite starts at ∼280 °C, while that of natural Al-goethite starts at ∼320 °C, and the addition of NaOH can accelerate the conversion. The formed hematite inherits the needle-like appearance of the original Al-goethite, has many holes on the surface due to dehydroxylation, and no migration of aluminum elements occurs during the roasting process, indicating that Al-goethite transformed into porous Al-substituted hematite (Al-hematite), which is beneficial to the extraction of the aluminum retained in the hematite structure during Bayer digestion. To confirm the above results, digestion experiments (without or with roasting for typical Bayer digestion or low-temperature roasting-Bayer digestion) were carried out with gibbsitic bauxite and the one roasted at 400 °C for 30 min as raw materials, respectively. Compared to the typical Bayer digestion, the relative alumina recovery of low-temperature roasting-Bayer digestion increased from 90.06% to 95.65%, the red mud yield decreased from 36.32% to 34.08%, and the grade of Fe in red mud increased from 48.45% to 52.88% at 270 °C for 60 min. Enhanced transformation of Al-goethite significantly improves alumina recovery and the resultant iron-rich red mud can be easily co-processed in the steel industry, thus significant emission reduction of red mud from the Bayer system might be achieved.

Enhanced phosphate removal with fine activated alumina synthesized from a sodium aluminate solution: performance and mechanism.

Fine activated alumina (FAA) acting as an adsorbent for phosphate was synthesized from an industrial sodium aluminate solution based on phase evolution from Al(OH)3 and NH4Al(OH)2CO3. This material was obtained in the form of γ-Al2O3 with an open mesoporous structure and a specific surface area of 648.02 m2 g-1. The phosphate adsorption capacity of the FAA gradually increased with increases in phosphate concentration or contact time. The maximum adsorption capacity was 261.66 mg g-1 when phosphate was present as H2PO4 - at a pH of 5.0. A removal efficiency of over 96% was achieved in a 50 mg L-1 phosphate solution. The adsorption of phosphate anions could be explained using non-linear Langmuir or Freundlich isotherm models and a pseudo-second-order kinetic model. Tetra-coordinate AlO4 sites acting as Lewis acids resulted in some chemisorption, while (O) n Al(OH)2 + (n = 4, 5, 6) Brønsted acid groups generated by the protonation of AlO4 or AlO6 sites in the FAA led to physisorption. Analyses of aluminum-oxygen coordination units using Fourier transform infrared and X-ray photoelectron spectroscopy demonstrated that physisorption was predominant. Minimal chemisorption was also verified by the significant desorption rate observed in dilute NaOH solutions and the high performance of the regenerated FAA. The high specific surface area, many open mesopores and numerous highly active tetra-coordinate AlO4 sites on the FAA all synergistically contributed to its exceptional adsorption capacity.

Fabrication of Raspberry-like Cytochrome C Surface-Imprinted Nanoparticles Based on MOF Composites for High-Performance Protein Separation.

The development of high-performance protein-imprinted materials is vital to meet the requirements of proteomics research but remains a challenge. Herein, a new type of raspberry-like cytochrome C-imprinted nanoparticle was first designed and fabricated via surface imprinting technology combined with a template immobilization strategy. In particular, the state-of-the-art metal-organic framework (MOF)/carbon nanoparticle (CN) composites were selected as protein immobilization carriers for two advantages: (1) the composites reflected the intrinsic characteristics of MOFs including flexible design, facile preparation, and extensive interactions with proteins and (2) the utilization of composites also overcame the issue associated with the severe agglomeration of individual MOFs during the post-use process. Therefore, the as-prepared composites exhibited a regular raspberry-like shape with good dispersion (polydispersity index (PDI) < 0.25), high specific surface area (551.4 m2 g-1), and outstanding cytochrome C immobilization capacity (900 mg g-1). Furthermore, a zwitterionic monomer was chosen to participate in the synthesis of an imprinting layer to reduce the nonspecific binding with proteins. As a result, the unique design presented here in both the protein immobilization carrier and the selected polymer composition endowed the imprinted material (noted as CN@UIO-66@MIPs) with the excellent ability for cytochrome C enrichment with extremely high recognition ability (imprinting factor (IF) = 6.1), rapid adsorption equilibrium time (40 min), and large adsorption capacity (815 mg g-1). Furthermore, encouraged by the experimental results, we successfully used CN@UIO-66@MIPs to specifically capture cytochrome C in mixed protein solutions and biological samples, which proved them to be a potential candidate for protein separation and purification.

Formic Acid as a Potential On-Board Hydrogen Storage Method: Development of Homogeneous Noble Metal Catalysts for Dehydrogenation Reactions.

Hydrogen can be used as an energy carrier for renewable energy to overcome the deficiency of its intrinsically intermittent supply. One of the most promising application of hydrogen energy is on-board hydrogen fuel cells. However, the lack of a safe, efficient, convenient, and low-cost storage and transportation method for hydrogen limits their application. The feasibility of mainstream hydrogen storage techniques for application in vehicles is briefly discussed in this Review. Formic acid (FA), which can reversibly be converted into hydrogen and carbon dioxide through catalysis, has significant potential for practical application. Historic developments and recent examples of homogeneous noble metal catalysts for FA dehydrogenation are covered, and the catalysts are classified based on their ligand types. The Review primarily focuses on the structure-function relationship between the ligands and their reactivity and aims to provide suggestions for designing new and efficient catalysts for H2 generation from FA.

Preparation of a poly(ionic liquid)-functionalized cellulose aerogel and its application in protein enrichment and separation.

In this work, a novel poly(ionic liquid) with 1-vinyl-3-aminopropyl imidazolium cations was designed and used to modify cellulose aerogels via Schiff base reaction. The poly(ionic liquid) modified cellulose aerogels (PIL-CA) exhibited a well-interconnected porous structure and a high porosity of 86.2%. A zeta potential study showed the PIL-CA had a strong positive potential of more than 65 mV when its pH was below 6. Furthermore, after 350 min of adsorption experiments, the PIL-CA showed a superior adsorption capacity of 918 ± 8 mg g-1 towards bovine serum albumin (BSA) at pH 6 when its concentration was 1.5 mg m L-1. Finally, the PIL-CA was employed for the selective separation of target protein from a real serum sample, obtaining the BSA with high purity of over 98%.

Efficient separation of silica and alumina in simulated CFB slag by reduction roasting-alkaline leaching process.

Although circulating fluidized bed (CFB) combustion technology is regarded as an efficient technology to use abundant coal gangue as fuel, large amounts of CFB slag has to be stockpiled and raises the environmental stress. This work focused on the comprehensive utilization of silica and alumina in CFB slag. The combustion process of coal gangue and the subsequent separation of alumina and silica by alkaline leaching of the simulated CFB slag were investigated. The results show that, in the combustion process, kaolinite in coal gangue firstly converts into meta-kaolinite at 600-900 °C due to dehydroxylation, and then the meta-kaolinite splits into mullite and amorphous silica at ≥1000 °C. Whereas by reduction roasting with hematite, the CFB slag simulated at 800-1100 °C can be completely converted into hercynite and free silica in forms of quartz solid solution and cristobalite solid solution. However, the conversion reaction rate for the CFB slag simulated at 1200 °C decreases significantly due to the formation of well crystallized mullite prior to the reduction roasting. Additionally, either quartz solid solution or cristobalite solid solution is readily soluble and hercynite is insoluble in alkaline solution. Under optimal conditions, more than 95% of silica in the reduction roasted product can be dissolved in alkaline solution and the mass ratio of alumina to silica in the leached residue can increase from 0.85 to above 20. This study lays a foundation for developing a novel technique to efficiently recycle the carbon, silica and alumina in coal gangue and thus to alleviate the environmental stress.

A green approach of preparation of fine active alumina with high specific surface area from sodium aluminate solution.

Fine active alumina (FAA) with a high specific surface area (SSA) is used in catalysis, adsorbents and other applications. This study presents a novel method of preparing high surface area FAA via a phase evolution from gibbsite through ammonium aluminum carbonate hydroxide (AACH) to FAA. Thermodynamic calculations showed that increasing the pH and (NH4)2CO3 concentration both promoted the transformation of gibbsite to AACH. Fine gibbsite precipitated from a sodium aluminate solution could thus be efficiently changed to AACH and subsequently to FAA. Minimal particle aggregation was achieved from gibbsite to AACH to FAA owing to the filling of capillaries by NH3 and CO2, the formation of boehmite and interfacial hydrophobicity. Furthermore, capillary pressures of 1.25-46.56 MPa during the AACH roasting process prevented the collapse of mesopores. The high capillary pressure, numerous open mesopores, and inhibition of aggregation produced FAA with an extremely high SSA. The SSA of FAA was as high as 1088.72 m2 g-1 following the roasting of AACH at 300 °C for 180 min. This FAA was demonstrated to remove phosphate from wastewater with an adsorption capacity of 300.28 mg g-1.

Solvothermally Controlled Synthesis of Organic-Inorganic Hybrid Nanosheets as Efficient pH-Universal Hydrogen-Evolution Electrocatalysts.

Electrocatalysts with a high efficiency and durability for the hydrogen evolution reaction (HER) hold tremendous promise for next-generation energy conversion. Among the state-of-art catalysts for HER, organic-inorganic hybrid nanosheets exhibit a great potential with the merits of high activity, good durability, and low cost. Nevertheless, there is no general method for the synthesis of binary metal phosphide hybrid nanosheet HER catalysts with a tunable morphology and composition. Herein, we report a facile approach for the synthesis of nanosheets consisting of a binary cobalt nickel phosphide hybrid with a hierarchically porous nanostructures using an oxidation- phosphorization process. The as-optimized hybrid nanosheets annealed at 350 °C yield the highest pH-universal activity with overpotentials of 148, 111, and 173 mV in acidic, alkaline, and neutral media, respectively. Besides the promoted mass diffusion in the hierarchically porous structure, the extraordinary performance can be also attributed to the weakened adsorption of hydrogen as a result of the tunable composition of Co and Ni, which was revealed by first-principles calculations.

Anti-fatigue activity of extracts of stem bark from Acanthopanax senticosus.

In the present study, we investigated the anti-fatigue activity in male Kunming mice of extracts of stem bark from Acanthopanax senticosus (ASSE) using a forced swimming test. Mice were divided into four groups (three ASSE administered groups and the control group). The control group were gavaged with distilled water and ASSE administered groups were gavaged with ASSE (100, 200 and 400 mg/kg). After four weeks, a forced swimming test was performed and the biochemical parameters related to fatigue were examined. The results suggested that ASSE could extend the swimming time to exhaustion of the mice, as well as increase the tissue glycogen contents, while decreasing the blood lactate and serum urea nitrogen contents. This indicated that ASSE had anti-fatigue activity and could elevate the exercise tolerance.