Search Results (6)

Efficient pretreatment is essential for improving the conversion of lignocellulose into fermentable sugars and bioethanol. In this study, choline chloride–monoethanolamine (ChCl-MEA)-based solvent systems containing H₂O₂, NaHCO₃, Na₂S, or ethylene glycol were prepared and applied for the pretreatment of Dendrocalamus brandisii. Among the tested systems, ChCl-MEA-Na₂S showed the best overall pretreatment performance, achieving 92.8 ± 2.3% delignification and 86.1 ± 1.7% cellulose retention. It also effectively disrupted lignin–carbohydrate associations, reduced lignin shielding and generated a more accessible cellulose-rich substrate for bioconversion. In the following separation enzymatic hydrolysis and fermentation, 92.2 ± 2.2% cellulose in substrate was converted to glucose, and 17.49 ± 0.7 g/L ethanol was obtained via the fermentation of enzymatic hydrolysate. Taking the bioconversion of substrate into consideration, the ChCl-MEA-H₂O₂ and ChCl-MEA-Na₂S were recovered for full component utilization. Especially, the carbon dots produced from the degradation compounds in ChCl-MEA-H₂O₂ DESs had favorable antioxidation and antibacterial performance due to the oxygen-containing group caused by oxidation of H₂O₂. Full article

Aqueous zinc-ion batteries (AZIBs) are highly promising for large-scale energy storage applications owing to their distinct merits, such as exceptional safety, abundant zinc reserves, high ionic conductivity, and facile manufacturing. Featuring natural abundance, low cost, environmental benignity, and high theoretical specific capacity, Mn₂O₃ has emerged as one of the most competitive cathode candidates for AZIBs. However, the low electrical conductivity of Mn₂O₃ impedes electron transport within the electrode, leading to significant polarization during charging and discharging and poor rate performance. Therefore, this study focuses on Mn₂O₃, and combines it with lignin-derived N,S-co-doped carbon dots (NS-CDs). Through a composite modification strategy, efficient conductive pathways are constructed and the structure of Mn₂O₃ is stabilized simultaneously, thereby effectively enhancing the electrical conductivity of the modified cathode. The incorporation of NS-CDs improves the high-rate response of the Mn₂O₃ cathode, with the optimized composite retaining capacity stability at 5 A g⁻¹. At 0.2 A g⁻¹, the specific capacity reaches 174 mAh g⁻¹, and at a current density of 1 A g⁻¹, the material can sustain 1000 cycles. These results highlight biomass-derived carbon dots as a viable interfacial modifier for Mn-based AZIB cathodes. Full article

A NiCo₂S₄/N-CDs/RGO ternary composite hydrogel was prepared via a one-step hydrothermal method, utilizing lignin-based nitrogen-doped carbon dots as a bridge connecting NiCo₂S₄ and graphene. The specific capacitance of NiCo₂S₄/N-CDs/RGO significantly outperforms that of the GH and NiCo₂S₄/RGO electrodes, achieving 1050 F g⁻¹. The 3D mesh porous hydrogel structure mitigates NiCo₂S₄ nanoparticle aggregation, providing a larger specific surface area for enhanced charge storage. The abundant functional groups of N-CDs interact with Ni (II) and Co (III) cations, favoring NiCo₂S₄ particle synthesis. Additionally, an assembled solid-state asymmetric supercapacitor employing NiCo₂S₄/N-CDs/RGO as the positive electrode exhibited excellent energy density (68.4 Wh kg⁻¹) and cycle stability (82% capacitance retention after 10,000 constant current charge–discharge cycles). Full article

Carbon quantum dots (CQDs) have been investigated for biomedical applications in medical imaging due to their fluorescent properties, overall long-term stability, and excellent cytocompatibility and biocompatibility. Lignin is an organic polymer in the tissues of woody plants. It is also considered a byproduct of the wood and pulp industries. Hence, it presents as a renewable source of carbon nanoparticles. In this study, we report the synthesis and material and biological characterization of two colloidal suspensions of CQDs in water derived from lignin-based carbon. One was the native form of CQDs derived from lignin carbon, and the second was doped with nitrogen to evaluate material differences. Material characterization was carried out using various commonly used techniques, including Fourier transform infrared spectroscopy (FTIR), emission and absorbance spectra, zeta potential, transmission electron microscopy (TEM), and scanning electron microscopy (SEM). Thin films of CQDs were formed on glass and silicon substrates to assess the in vitro cytocompatibility with human mesenchymal stem cells (hMSCs). Observations suggest that the two forms of CQDs promote cell attachment within 24 h and sustain it for at least 7 days. The overall structure and shape of cells suggest a lack of any adverse or toxic effects of CQDs. The data lay down the novel foundation to support the use of lignin-derived CQDs in tissue engineering applications. Full article

The continuous increase of the demand in merchandise and fuels augments the need of modern approaches for the mass-production of renewable chemicals derived from abundant feedstocks, like biomass, as well as for the water and soil remediation pollution resulting from the anthropogenic discharge of organic compounds. Towards these directions and within the concept of circular (bio)economy, the development of efficient and sustainable catalytic processes is of paramount importance. Within this context, the design of novel catalysts play a key role, with carbon-based nanocatalysts (CnCs) representing one of the most promising class of materials. In this review, a wide range of CnCs utilized for biomass valorization towards valuable chemicals production, and for environmental remediation applications are summarized and discussed. Emphasis is given in particular on the catalytic production of 5-hydroxymethylfurfural (5-HMF) from cellulose or starch-rich food waste, the hydrogenolysis of lignin towards high bio-oil yields enriched predominately in alkyl and oxygenated phenolic monomers, the photocatalytic, sonocatalytic or sonophotocatalytic selective partial oxidation of 5-HMF to 2,5-diformylfuran (DFF) and the decomposition of organic pollutants in aqueous matrixes. The carbonaceous materials were utilized as stand-alone catalysts or as supports of (nano)metals are various types of activated micro/mesoporous carbons, graphene/graphite and the chemically modified counterparts like graphite oxide and reduced graphite oxide, carbon nanotubes, carbon quantum dots, graphitic carbon nitride, and fullerenes. Full article

The utilization of biomass waste to produce valuable products has extraordinary advantages as far as both the economy and climate are concerned, which have become particularly significant lately. The large-scale manufacturing of agricultural waste, mainly rice by-products (rice husk, rice straw, and rice bran), empowers them to be the most broadly examined biomasses as they contain lignin, cellulose, and hemicellulose. Rice waste was first used to incorporate bulk materials, while the manufacturing of versatile nanostructures from rice waste at low cost has been developed in recent years and attracts much consideration nowadays. Carbon-based nanomaterials including graphene, carbon nanotubes, carbon dots, fullerenes, and carbon nanofibers have tremendous potential in climate and energy-related applications. Various methods have been reported to synthesize high-value carbon nanomaterials, but the use of green technology for the synthesis of carbon nanomaterials is most common nowadays because of the abundant availability of the starting precursor, non-toxicity, low fabrication cost, ease of modification, and eco-friendly nature; therefore, reusing low-value biomass waste for the processing of renewable materials to fabricate high-value products is remarkable. Carbon nanomaterials derived from rice waste have broad applications in various disciplines owing to their distinctive physicochemical, electrical, optical, mechanical, thermal, and enhanced biocompatibility properties. The main objective of this review and basic criteria of selecting examples and explanations is to highlight the green routes for the synthesis of carbon nanomaterials—i.e., graphene, carbon nanotubes, and carbon dots—from rice biomass waste, and their extensive applications in biomedical research (bio-imaging), environmental (water remediation), and energy-related (electrodes for supercapacitors, Li-ion battery, fuel cells, and solar cells) applications. This review summarizes recent advancements, challenges, and trends for rice waste obtained from renewable resources for utilization in the fabrication of versatile carbon-based nanomaterials. Full article