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1.
ACS Nano ; 18(21): 13568-13582, 2024 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-38723039

RESUMO

Transition metal oxides are promising catalysts for catalytic oxidation reactions but are hampered by low room-temperature activities. Such low activities are normally caused by sparse reactive sites and insufficient capacity for molecular oxygen (O2) activation. Here, we present a dual-stimulation strategy to tackle these two issues. Specifically, we import highly dispersed nickel (Ni) atoms onto MnO2 to enrich its oxygen vacancies (reactive sites). Then, we use molecular ozone (O3) with a lower activation energy as an oxidant instead of molecular O2. With such dual stimulations, the constructed O3-Ni/MnO2 catalytic system shows boosted room-temperature activity for toluene oxidation with a toluene conversion of up to 98%, compared with the O3-MnO2 (Ni-free) system with only 50% conversion and the inactive O2-Ni/MnO2 (O3-free) system. This leap realizes efficient room-temperature catalytic oxidation of transition metal oxides, which is constantly pursued but has always been difficult to truly achieve.

2.
Adv Colloid Interface Sci ; 329: 103176, 2024 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-38761603

RESUMO

Single-atom catalysts (SACs) with active metals dispersed atomically have shown great potential in heterogeneous catalysis due to the high atomic utilization and superior selectivity/stability. Synthesis of SACs using carbon-neutral biomass and its components as the feedstocks provides a promising strategy to realize the sustainable and cost-effective SACs preparation as well as the valorization of underused biomass resources. Herein, we begin by describing the general background and status quo of carbon-based SACs derived from biomass. A detailed enumeration of the common biomass feedstocks (e.g., lignin, cellulose, chitosan, etc.) for the SACs preparation is then offered. The interactions between metal atoms and biomass-derived carbon carriers are summarized to give general rules on how to stabilize the atomic metal centers and rationalize porous carbon structures. Furthermore, the widespread adoption of catalysts in diverse domains (e.g., chemocatalysis, electrocatalysis and photocatalysis, etc.) is comprehensively introduced. The structure-property relationships and the underlying catalytic mechanisms are also addressed, including the influences of metal sites on the activity and stability, and the impact of the unique structure of single-atom centers modulated by metal/biomass feedstocks interactions on catalytic activity and selectivity. Finally, we end this review with a look into the remaining challenges and future perspectives of biomass-based SACs. We expect to shed some light on the forthcoming research of carbon-based SACs derived from biomass, manifestly stimulating the development in this emerging research area.

3.
Int J Biol Macromol ; 259(Pt 2): 129138, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38171445

RESUMO

Efficient fractionation of lignocellulosic biomass in usable forms of hemicellulose, cellulose and lignin is very important for the sustainable lignocellulosic biorefinery. Herein, poplar sawdust was pretreated with an integrated process composed of acetic acid pre-hydrolysis (170 °C, 60 min) for xylo-oligosaccharides (XOS) production and mild deep eutectic solvent (90-130 °C, 60 min) post-delignification for recovering lignin fractions, resulting in easily hydrolyzed cellulose fraction. Results showed that, after integrated pretreatment and enzymatic hydrolysis, 51 % of xylan and 92 % of glucan in raw biomass could be converted to XOS (DP 2-6) and glucose, respectively, while 71 % of the original lignin could be recovered in DES solvent. The resulting XOS were proven to ensure the growth of probiotics, Bifidobacterium adolescentis. Besides, the lignin macromolecules recovered from DES solvent showed high-purity (around 95 %), low-molecular weight (Mw around 2000), small particle size (270-170 nm) and high-PhOH (3.08 mmol/g) content, which were likely relevant to the excellent antioxidant activity (RSI = 15.16) and adsorbent activity (Pb(II) 461.89 mg/g lignin). Finally, mass balance and energy analysis revealed that the integrated pretreatment could be used as a promising approach for the production of bio-based chemicals and materials from woody biomass.


Assuntos
Lignina , Açúcares , Antioxidantes/farmacologia , Solventes Eutéticos Profundos , Ácido Acético , Solventes , Celulose , Oligossacarídeos , Hidrólise , Biomassa
4.
J Colloid Interface Sci ; 659: 520-532, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38184994

RESUMO

The novel composite photocatalytic material perylene diimides/Fe2O3@C (PDIs/Fe2O3@C) was constructed by a simple hydrothermal-calcination method and an oil bath method. 20 % PDIs/Fe2O3@C displayed a 16.4-fold increase in the rate of tetracycline (TC) removal over Fe2O3@C at 8 min. The main factor that enhanced photocatalytic performance was due to the combination of PDIs with Fe2O3@C, which effectively improved the phenomenon during the self-assembly of highly agglomerative PDIs, increased the specific surface area of Fe2O3@C, exposed more reaction sites, and promoted the activation of peroxymonosulfate (PMS) by Fe2+/Fe3+; and secondly, the composite of two different materials, both organic and inorganic, which effectively promoted the photogenerated electron transfer and the separation of electron-hole pairs, the a new S-scheme electron transport pathway is formed, which effectively promoted the photogenerated electron transfer as well as the e--h+ separation, which was more favorable for the activation of PMS. The whole reaction pathway and product toxicity were thoroughly evaluated by Fukui function calculations, Liquid Chromatograph Mass Spectrometer (LC-MS), and Toxicity Estimation Software Tool (T.E.S.T.) simulation results, which demonstrated the rationality of the degradation pathway and the greatly reduced product toxicity. Moreover, the composites were effective and versatile for all other antibiotics (chlortetracycline (CTC), ciprofloxacin (CIP) and sulfadiazine (SDZ)). As an advanced oxidation process, the activation of PDIs/Fe2O3@C under visible light shows its potential application in pollutant degradation, which provides new perspectives and ideas for further effective treatment of real wastewater.


Assuntos
Antibacterianos , Peróxidos , Perileno , Antibacterianos/farmacologia , Elétrons , Luz
5.
Small ; 20(2): e2304404, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37670529

RESUMO

Cyano-rich g-C3 N4 materials are widely used in various fields of photochemistry due to the very powerful electron-absorbing ability and electron storage function of cyano, as well as its advantages in improving light absorption, adjusting the energy band structure, increasing the polarization rate and electron density in the structure, active site concentration, and promoting oxygen activation ability. Notwithstanding, there is yet a huge knowledge break in the design, preparation, detection, application, and prospect of cyano-rich g-C3 N4 . Accordingly, an overall review is arranged to substantially comprehend the research progress and position of cyano-rich g-C3 N4 materials. An overall overview of the current research position in the synthesis, characterization (determination of their location and quantity), application, and reaction mechanism analysis of cyano-rich g-C3 N4 materials to provide a quantity of novel suggestions for cyano-modified carbon nitride materials' construction is provided. In view of the prevailing challenges and outlooks of cyano-rich g-C3 N4 materials, this paper will purify the growth direction of cyano-rich g-C3 N4 , to achieve a more in-depth exploration and broaden the applications of cyano-rich g-C3 N4 .

6.
Small ; 20(15): e2304574, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38009795

RESUMO

Direct selective transformation of greenhouse methane (CH4) to liquid oxygenates (methanol) can substitute energy-intensive two-step (reforming/Fischer-Tropsch) synthesis while creating environmental benefits. The development of inexpensive, selective, and robust catalysts that enable room temperature conversion will decide the future of this technology. Single-atom catalysts (SACs) with isolated active centers embedded in support have displayed significant promises in catalysis to drive challenging reactions. Herein, high-density Ni single atoms are developed and stabilized on carbon nitride (NiCN) via thermal condensation of preorganized Ni-coordinated melem units. The physicochemical characterization of NiCN with various analytical techniques including HAADF-STEM and X-ray absorption fine structure (XAFS) validate the successful formation of Ni single atoms coordinated to the heptazine-constituted CN network. The presence of uniform catalytic sites improved visible absorption and carrier separation in densely populated NiCN SAC resulting in 100% selective photoconversion of (CH4) to methanol using H2O2 as an oxidant. The superior catalytic activity can be attributed to the generation of high oxidation (NiIII═O) sites and selective C─H bond cleavage to generate •CH3 radicals on Ni centers, which can combine with •OH radicals to generate CH3OH.

7.
ACS Sens ; 9(2): 799-809, 2024 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-38148619

RESUMO

This research focuses on developing and validating a wearable electrochemical biosensor called the concatenated aptamer integrated skin patch, also known as the Captain Patch. The main objective is to detect cortisol levels in sweat, which can provide valuable insights into an individual's health. The biosensor utilizes a corrugated surface that mimics the skin, allowing for better attachment and an improved electrochemical performance. The study demonstrates the successful application of Captain Patch on the human body by using artificially spiked sweat samples. The results indicate good measurement accuracy and conformity when the patch is worn on the body. However, for long-term usage, the patch needs to be changed every 3-4 h or worn three times a day to enable monitoring of cortisol levels. Despite the need for frequent patch changes, the cost-effectiveness and ease of operation make these skin patches suitable for longitudinal cortisol monitoring and other sweat analytes. By customization of the biorecognition probe, the developed biowearable can be used to monitor a variety of vital biomarkers. Overall, Captain Patch, with its capability of detecting specific health markers such as cortisol, hints at the future potential of wearables to offer valuable data on various other biomarkers. Our approach presents the first step in integrating a cost-effective wearable electrochemical patch integrated with a redox-concatenated aptamer for noninvasive biomarker detection. This personalized approach to monitoring can lead to improved patient outcomes and increased patient engagement in managing their health.


Assuntos
Técnicas Biossensoriais , Dispositivos Eletrônicos Vestíveis , Humanos , Hidrocortisona , Técnicas Biossensoriais/métodos , Oxirredução , Biomarcadores
8.
Macromol Biosci ; : e2300376, 2023 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-38031512

RESUMO

Even with the current advancements in wound management, addressing most skin injuries and wounds continues to pose a significant obstacle for the healthcare industry. As a result, researchers are now focusing on creating innovative materials utilizing cellulose and its derivatives. Cellulose, the most abundant biopolymer in nature, has unique properties that make it a promising material for wound healing, such as biocompatibility, tunable physiochemical characteristics, accessibility, and low cost. 3D bioprinting technology has enabled the production of cellulose-based wound dressings with complex structures that mimic the extracellular matrix. The inclusion of bioactive molecules such as growth factors offers the ability to aid in promoting wound healing, while cellulose creates an ideal environment for controlled release of these biomolecules and moisture retention. The use of 3D bioprinted cellulose-based wound dressings has potential benefits for managing chronic wounds, burns, and painful wounds by promoting wound healing and reducing the risk of infection. This review provides an up-to-date summary of cellulose-based dressings manufactured by 3D bioprinting techniques by looking into wound healing biology, biofabrication methods, cellulose derivatives, and the existing cellulose bioinks targeted toward wound healing.

9.
Chem Soc Rev ; 52(22): 7687-7706, 2023 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-37877319

RESUMO

Atomically thin sheets (e.g., graphene and monolayer molybdenum disulfide) are ideal optical and reaction platforms. They provide opportunities for deciphering some important and often elusive photocatalytic phenomena related to electronic band structures and photo-charges. In parallel, in such thin sheets, fine tuning of photocatalytic properties can be achieved. These include atomic-level regulation of electronic band structures and atomic-level steering of charge separation and transfer. Herein, we review the physics and chemistry of electronic band structures and photo-charges, as well as their state-of-the-art characterization techniques, before delving into their atomic-level deciphering and mastery on the platform of atomically thin sheets.

10.
Chemosphere ; 344: 140287, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37820879

RESUMO

In this research, graphitic carbon nitride/zinc oxide-copper denoted as GCN/ZnO-Cu nanocomposite photocatalysts were synthesized using a novel facile synthesis process, the co-exfoliation method involving ultrasonic exfoliation of the mixture of GCN and ZnO-Cu in ethanol and then thermal exfoliation. Different characterization techniques such as X-ray diffraction (XRD), mean crystallite size (MCS), BET surface area, transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), particle size distribution (PSD), Fourier transform-infrared spectroscopy (FT-IR), photoluminescence (PL) spectra, and ultraviolet-visible diffuse reflectance spectroscopy (UV-Vis DRS) were conducted to study the crystallinity, morphology, elemental composition, chemical structure, and optoelectronic properties. The band gap was estimated using the UV-Vis DRS results and Tauc plots. The photocatalytic activity of the GCN/ZnO-Cu3% nanocomposites was evaluated in the degradation of 4-chlorophenol (4-CP), and the disinfection of wastewater primary influent under a narrowband visible light source, royal blue LED (λ = 450 nm). GCN/0.1ZnO-Cu3% nanocomposite showed the best performance in the degradation of 4-CP and the disinfection of municipal wastewater primary influent. For 4-CP degradation, GCN/0.1ZnO-Cu3% was 2.2 times better than GCN, 9.4 times better than ZnO-Cu3%, and 1.8 times better than the sum of the individual GCN and ZnO-Cu3%. A 5.5 log reduction was achieved for the disinfection of total coliforms in wastewater primary influent in 360 min. This enhanced photocatalytic activity of GCN/ZnO-Cu3% nanocomposite can be attributed to the synergistic of GCN and the ZnO-Cu3%, resulting in a large surface area and improved bandgap.


Assuntos
Nanocompostos , Óxido de Zinco , Óxido de Zinco/química , Águas Residuárias , Cobre/química , Espectroscopia de Infravermelho com Transformada de Fourier , Desinfecção , Luz , Nanocompostos/química , Catálise
11.
Polymers (Basel) ; 15(18)2023 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-37765666

RESUMO

Blood vessels are crucial in the human body, providing essential nutrients to all tissues while facilitating waste removal. As the incidence of cardiovascular disease rises, the demand for efficient treatments increases concurrently. Currently, the predominant interventions for cardiovascular disease are autografts and allografts. Although effective, they present limitations including high costs and inconsistent success rates. Recently, synthetic vascular grafts, made from artificial materials, have emerged as promising alternatives to traditional methods. Among these materials, bacterial cellulose hydrogel exhibits significant potential for tissue engineering applications, particularly in developing nanoscale platforms that regulate cell behavior and promote tissue regeneration, attributed to its notable physicochemical and biocompatible properties. This study reviews recent progress in fabricating engineered vascular grafts using bacterial nanocellulose, demonstrating the efficacy of bacterial cellulose hydrogel as a biomaterial for synthetic vascular grafts, specifically for stimulating angiogenesis and neovascularization.

12.
ChemSusChem ; 16(23): e202300675, 2023 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-37455297

RESUMO

Photoreforming of lignocellulosic biomass to simultaneously produce gas fuels and value-added chemicals has gradually emerged as a promising strategy to alleviate the fossil fuels crisis. Compared to cellulose and hemicellulose, the exploitation and utilization of lignin via photoreforming are still at the early and more exciting stages. This Review systematically summarizes the latest progress on the photoreforming of lignin-derived model components and "real" lignin, aiming to provide insights for lignin photocatalytic valorization from fundamental to industrial applications. Considering the complexity of lignin physicochemical properties, related analytic methods are also introduced to characterize lignin photocatalytic conversion and product distribution. We finally put forward the challenges and perspective of lignin photoreforming, hoping to provide some guidance to valorize biomass into value-added chemicals and fuels via a mild photoreforming process in the future.

13.
Adv Colloid Interface Sci ; 318: 102958, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37453344

RESUMO

Complex structures and morphologies in nature endow materials with unexpected properties and extraordinary functions. Biotemplating is an emerging strategy for replicating nature structures to obtain materials with unique morphologies and improved properties. Recently, efforts have been made to use bio-inspired species as a template for producing morphology-controllable catalysts. Fundamental information, along with recent advances in biotemplate metal-based catalysts are presented in this review through discussions of various structures and biotemplates employed for catalyst preparation. This review also outlines the recent progress on preparation routes of biotemplate catalysts and discusses how the properties and structures of these templates play a crucial role in the final performance of metal-based catalysts. Additionally, the application of bio-based metal and metal oxide catalysts is highlighted for various key energy and environmental technologies, including photocatalysis, fuel cells, and lithium batteries. Biotemplate metal-based catalysts display high efficiency in several energy and environmental systems. Note that this review provides guidance for further research in this direction.

14.
Bioresour Technol ; 386: 129579, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37506939

RESUMO

Mild hydrothermal pretreatment (HP) integrating with solvent extraction is a promising two-step technique to enhance the overall lignin and carbohydrate output for lignocellulose fractionation. This work comparatively assessed the coupling effect between mild HP (the first step) and the emerging acidic choline chloride-natural acid or alkaline choline hydroxide based deep eutectic solvents (DES, the second step) for wheat straw fractionation. It was shown HP with 0.3% p-toluenesulfonic acid (p-TsOH) catalyst achieved a good compromise between complete hemicellulose removal (nearly 100%) and high cellulose recovery (99.2%). While choline hydroxide based DES showed better coupling effect with HP than choline chloride-natural acid DES, corresponding to 75.6 and 31.2% lignin removal respectively. It was proposed that the alkaline DES enhanced lignocellulose swelling the lignin phenolic hydroxyl groups deprotonation and thus facilitating lignin solubilization despite of its condensation at HP. Therefore, the alkaline DES resulting cellulose-rich fraction exhibited higher potential for further processing.


Assuntos
Lignina , Triticum , Solventes Eutéticos Profundos , Solventes , Biomassa , Celulose , Colina , Catálise , Hidrólise
15.
Bioresour Technol ; 383: 129178, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37270148

RESUMO

This study reported that surfactants could facilitate the organosolv pretreatment of lignocellulosic biomass (LCB) to produce fermentable sugars and highly active lignin. Under the optimized conditions, the surfactant-assisted glycerol organosolv (saGO) pretreatment achieved 80.7% delignification with a retention of 93.4% cellulose and 83.0% hemicellulose. The saGO pretreated substrate exhibited an excellent enzymatic hydrolyzability, achieving 93% of glucose yield from the enzymatic hydrolysis at 48 h. Structural analysis showed that the saGO lignin contained rich ß-O-4 bondings with less repolymerization and lower phenolic hydroxyl groups, thus forming highly reactive lignin fragments. The analysis evidenced that the surfactant graft the lignin by structural modification, which was responsible for the excellent substrate hydrolyzability. The co-production of fermentable sugars and organosolv lignin almost recovered a gross energy (87.2%) from LCB. Overall, the saGO pretreatment holds a lot of promise for launching a novel pathway towards lignocellulosic fractionation and lignin valorization.


Assuntos
Glicerol , Lignina , Açúcares , Tensoativos , Biomassa , Hidrólise
16.
J Hazard Mater ; 457: 131824, 2023 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-37327610

RESUMO

Water ecosystem contamination from industrial pollutants is an emerging threat to both humans and native species, making it a point of global concern. In this work, fully biobased aerogels (FBAs) were developed by using low-cost cellulose filament (CF), chitosan (CS), citric acid (CA), and a simple and scalable approach, for water remediation applications. The FBAs displayed superior mechanical properties (up to ∼65 kPa m3 kg-1 specific Young's modulus and ∼111 kJ/m3 energy absorption) due to CA acting as a covalent crosslinker in addition to the natural hydrogen bonding and electrostatic interactions between CF and CS. The addition of CS and CA increased the variety of functional groups (carboxylic acid, hydroxyl and amines) on the materials' surface, resulting in super-high dye and heavy metal adsorption capacities (619 mg/g and 206 mg/g for methylene blue and copper, respectively). Further modification of FBAs with a simple approach using methyltrimethoxysilane endowed aerogel oleophilic and hydrophobic properties. The developed FBAs showed a fast performance in water and oil/organic solvents separation with more than 96% efficiency. Besides, the FBA sorbents could be regenerated and reused for multiple cycles without any significant impact on their performance. Moreover, thanks to the presence of amine groups by addition of CS, FBAs also displayed antibacterial properties by preventing the growth of Escherichia coli on their surface. This work demonstrates the preparation of FBAs from abundant, sustainable, and inexpensive natural resources for applications in wastewater purification.

17.
J Colloid Interface Sci ; 647: 255-263, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37253294

RESUMO

Selective photocatalysis to simultaneously produce sustainable hydrogen and value-added chemicals from biomass or biomass derivates is attracting extensive investigations. However, the lack of bifunctional photocatalyst greatly limits the possibility to realize the "one stone kills two birds" scenario. Herein, anatase titanium dioxide (TiO2) nanosheets are rationally designed as the n-type semiconductor, combining with nickel oxide (NiO) nanoparticles, the p-type semiconductor, resulting in the formation of a p-n heterojunction structure. The shorten charge transfer path and the spontaneous formation of p-n heterojunction endow the photocatalyst with efficient spatial separation of photogenerated electrons and holes. As a result, TiO2 accumulates electrons for efficient hydrogen generation while NiO collects holes to selectively oxidize glycerol into value-added chemicals. The results showed that by loading 5% nickel into the heterojunction caused a remarkable rise in the generation of hydrogen (H2). The combination of NiO-TiO2 created 4000 µmolh-1g-1 of H2, which is 50% greater than the H2 production from pure nanosheet TiO2 and 63 times more than the H2 production from commercial nanopowder TiO2. Then, by changing loading amount of Ni, it is found that when 7.5 % of Ni is loaded the highest amount of hydrogen production achieved, 8000 µmolh-1g-1. By employing best sample (S3), 20 % of glycerol converted to value added products, glyceraldehyde and dihydroxyacetone. The feasibility study revealed that glyceraldehyde generates the largest portion of yearly earnings at 89%, while dihydroxyacetone and H2 account for 11% and 0.03% of the annual revenue, respectively. This work provides a good example to simultaneously produce green hydrogen and valuable chemicals with the rational design of dually functional photocatalyst.

18.
Biotechnol Adv ; 66: 108157, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37084800

RESUMO

Lignocellulosic biomass valorization is regarded as a promising approach to alleviate energy crisis and achieve carbon neutrality. Bioactive enzymes have attracted great attention and been commonly applied for biomass valorization owing to their high selectivity and catalytic efficiency under environmentally benign reaction conditions. Same as biocatalysis, photo-/electro-catalysis also happens at mild conditions (i.e., near ambient temperature and pressure). Therefore, the combination of these different catalytic approaches to benefit from their resulting synergy is appealing. In such hybrid systems, harness of renewable energy from the photo-/electro-catalytic compartment can be combined with the unique selectivity of biocatalysts, therefore providing a more sustainable and greener approach to obtain fuels and value-added chemicals from biomass. In this review, we firstly introduce the pros/cons, classifications, and the applications of photo-/electro-enzyme coupled systems. Then we focus on the fundamentals and comprehensive applications of the most representative biomass-active enzymes including lytic polysaccharide monooxygenases (LPMOs), glucose oxidase (GOD)/dehydrogenase (GDH) and lignin peroxidase (LiP), together with other biomass-active enzymes in the photo-/electro- enzyme coupled systems. Finally, we propose current deficiencies and future perspectives of biomass-active enzymes to be applied in the hybrid catalytic systems for global biomass valorization.


Assuntos
Lignina , Biomassa , Catálise , Biocatálise
19.
J Hazard Mater ; 448: 130988, 2023 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-36860059

RESUMO

Developing the lignin-based functional materials for uranium uptake is extremely attractive, but challenging due to the complex structure, poor solubility and reactivity of lignin. Herein, a novel phosphorylated lignin (LP)/sodium alginate/ carboxylated carbon nanotube (CCNT) composite aerogel (LP@AC) with vertically oriented lamellar configuration was created for efficient uranium uptake from acidic wastewater. The successful phosphorylation of lignin by a facile solvent-free mechanochemical method achieved more than six-times enhancement in U(VI) uptake capacity of lignin. While, the incorporation of CCNT not only increased the specific surface area of LP@AC, but also improved its mechanical strength as a reinforcing phase. More importantly, the synergies between LP and CCNT components endowed LP@AC with an excellent photothermal performance, resulting in a local heat environment on LP@AC and further boosting the U(VI) uptake. Consequently, the light irradiated LP@AC exhibited an ultrahigh U(VI) uptake capacity (1308.87 mg g-1), 61.26% higher than that under dark condition, excellent adsorptive selectivity and reusability. After exposure to 10 L of simulated wastewater, above 98.21% of U(VI) ions could be rapidly captured by LP@AC under light irradiation, revealing the tremendous feasibility in industrial application. The electrostatic attraction and coordination interaction were considered as the main mechanism for U(VI) uptake.

20.
Carbohydr Polym ; 299: 120182, 2023 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-36876797

RESUMO

Acid pretreatment of biomass decomposed hemicelluloses but could not effectively remove lignin, which hindered biomass saccharification and carbohydrates utilization. In this work, 2-naphthol-7-sulfonate (NS) and sodium bisulfite (SUL) were simultaneously added to acid pretreatment, which was found to synergistically increase hydrolysis yield of cellulose from 47.9 % to 90.6 %. Based on in-depth investigations, strong linear correlations were observed between cellulose accessibility and lignin removal, fiber swelling, CrI/cellulose ratio, cellulose crystallite size, respectively, indicating that some physicochemical characteristics of cellulose played significant roles in improving cellulose hydrolysis yield. After enzymatic hydrolysis, 84 % carbohydrates could be liberated and recovered as fermentable sugars for subsequent utilization. Mass balance illustrated that for 100 kg raw biomass, 15.1 kg xylonic acid and 20.5 kg ethanol could be co-produced, indicating the efficient utilization of biomass carbohydrates.


Assuntos
Celulose , Lignina , Biomassa , Polissacarídeos
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