Heteroatom-doped and graphitization-enhanced lignin-derived hierarchically porous carbon via facile assembly of lignin-Fe coordination for high-voltage symmetric supercapacitors

Enhanced fluoride removal in a novel magnesium-carbon micro-electrolysis constructed wetland through accelerated electron transport and anodic sacrifice

High fluoride (F-) content in the aquatic environment is a significant‌ issue affecting public health. Constructed wetlands (CWs) are believed to have unique potential for alleviating F- pollution in the aquatic environment. In this study, magnesium (Mg) and iron/nitrogen co-doped biochar (FeNBC) was used as the filler of a novel micro-electrolysis constructed wetland (WNME). Compared with the control, WNME significantly enhanced the F- removal efficiency from 19.1 ± 7.3 % to 54.1 ± 8.3 %, in which 90.7 % of total F- removal in WNME was attributed to the micro-electrolysis filler. The enhancement was attributed to the co-doping of iron and nitrogen, which improved the surface morphology, element distribution, and electrochemical performance of FeNBC. This led to an increase in the potential of FeNBC by 9.8 %, thereby increasing the potential difference within the Mg-C micro-electrolysis system. The Mg2+ release from anodic sacrifice in WNME was promoted, which led to an increase in MgF2 as the precipitate. Micro-electrolysis promoted the enrichment of electrochemically active bacteria in WNME, resulting in enhanced electron transfer and high F- removal efficiency. This study provided new insights for F- removal in CWs and would shed light on the optimization of micro-electrolysis CWs for F- removal from the aqueous phase.

A review on the application of lignin-based carbon materials in supercapacitors: Fabrication of multi-dimensional morphologies and heteroatom doping

Supercapacitors are essential components in renewable energy storage systems due to their remarkable power density, swift charging/discharging speeds, extended lifespan across cycles, and ability to function effectively under diverse temperature conditions. Lignin, the second most plentiful biomass resource in nature following cellulose, is renowned for its wide availability, cost-effectiveness, and a rich array of bioactive components. It can be abundantly sourced as a by-product of pulp and biomass refineries. Given the growing concerns over environmental pollution and energy depletion, lignin is increasingly being recognized as a viable alternative to conventional petrochemical feedstocks. This paper presents a comprehensive overview of supercapacitors, outlining their fundamental principles and classification. This study delves into the structural characteristics and origins of lignin, highlighting the potential for optimizing crystallinity and properties of carbon materials derived from lignin through meticulous modifications of structural and carbonization parameters. This approach facilitates the tailored synthesis of polymorphic carbon materials, resulting in improved performance characteristics. Furthermore, the study investigates the substantial impact of non-metallic doping elements, including sulfur, phosphorus, and nitrogen, in conjunction with metallic elements such as copper, manganese, and nickel, on the enhancement of the electrochemical properties of carbon materials derived from lignin.

Hierarchical porous hollow of carbon spheres with high surface area for high performance supercapacitor electrode materials

In this paper, we demonstrate a synthesis of mesoporous carbon spheres via a self-assembly of resorcinol-formaldehyde polymer and surfactant F127 in aqueous phase in the presence of phytic acid as the catalyst and phosphorus source. The obtained mesoporous carbon spheres have high phosphorus content and excellent electrochemical performance. The enhancement of the electrochemical performance of the material is primarily attributed to the structural characteristics and chemical properties of phosphorus atoms being similar to those of nitrogen atoms, and the atomic radius being slightly larger than that of nitrogen atoms, with strong electron donating ability. After successful doping, rich active sites are formed. These carbon spheres are examined as electrode materials for supercapacitors. The structural characterization revealed that the mesoporous carbon spheres possessed an average pore diameter of 2.4 nm and a specific surface area of 1207 m2 g- 1. Electrochemical measurements demonstrated a specific capacitance of 257.5 F g- 1 at 0.5 A g- 1 in a three-electrode configuration. used as supercapacitor electrodes with a capacitance of 92.8 F g- 1 at a current density of 0.5 A g- 1. Furthermore, the energy density is 4.64 Wh Kg- 1 at a power density of 150 W Kg- 1 and the capacitance retention rate is 98.99% After 5000 cycles at a current density of 2 A g- 1, an extremely highly promising supercapacitor electrode material.

Lignocellulose-Mediated Functionalization of Liquid Metals toward the Frontiers of Multifunctional Materials

Lignocellulose-mediated liquid metal (LM) composites, as emerging functional materials, show tremendous potential for a variety of applications. The abundant hydroxyl, carboxyl, and other polar groups in lignocellulose facilitate the formation of strong chemical bonds with LM surfaces, enhancing wettability and adhesion for improved interface compatibility. Beyond serving as a supportive matrix, lignocellulose can be tailored to optimize the microstructure of the composites, adapting them for diverse applications. This review comprehensively summarizes the fundamental principles and recent advancements in lignocellulose-mediated LM composites, highlighting the advantages of lignocellulose in composite fabrication, including facile synthesis, versatile interactions, and inherent functionalities. Key modulation strategies for LMs and innovative synthesis methods for functionalized lignocellulose composites are discussed. Furthermore, the roles and structure-performance relationships of these composites in electromagnetic shielding, flexible sensors, and energy storage devices are systematically summarized. Finally, the obstacles and prospective advancements pertaining to lignocellulose-mediated LM composites are thoroughly scrutinized and deliberated upon. This review is expected to provide basic guidance for researchers to boost the popularity of LMs in diverse applications and provide useful references for design strategies of state-of-the-art LMs.

Ultrahigh-Power Carbon-Based Supercapacitors through Order-Disorder Balance

Although carbon-based supercapacitors (SCs) hold the advantages of high-power and large-current characteristics, they are difficult to realize ultrahigh-power density (> 200 kW kg-1) and maintain almost constant energy density at ultrahigh power. This limitation is mainly due to the difficulty in balancing the structural order related to the electrical conductivity of carbon materials and the structural disorder related to the pore structure. Herein, we design a novel super-structured tubular carbon (SSTC) with a crosslinked porous conductive network to solve the structure order-disorder tradeoff effect in carbon materials. The direct conversion of CO2 in combination with appropriate annealing treatment tailored SSTC that exhibits considerably high conductivity (≈19300 S m-1) along with an optimal mesoporous structure. Consequently, SSTC-based SCs show impressive ultrahigh-power and high-energy features as demonstrated from three aspects. First, SSTC-1000-based SCs with organic electrolytes deliver a maximum power density of 1138.8 kW kg-1. Second, the energy density retention is up to 84.6% as the power density increases from 0.7 to 280 kW kg-1. Third, SSTC-1000-based SC exhibits excellent ultrahigh-power durability as demonstrated by 93.7% capacitance retention after 100000 cycles at 200 A g-1.

The latest research progress on polysaccharides-based biosensors for food packaging: A review

In recent years, polysaccharide-based biosensors have emerged as promising technologies for intelligent food packaging, offering innovative solutions to enhance food quality and safety. This review highlights advancements in designing, developing, and applying these biosensors, particularly those utilizing polysaccharides such as chitosan, cellulose and alginate. Engineered with nanomaterials like ZnO, silver, and carbon nano-tubes demonstrated high sensitivity in real-time monitoring of food spoilage indicators, including pH changes, volatile nitrogen compounds and microbial activity. We discuss the electrochemical properties of these biosensors, highlighting how the integration of electrochemical methods significantly improves their detection capabilities within packaging environments, leading to sensor sensitivity enhancement, greater accuracy, and spoilage detection, ultimately extending the shelf life of perishable food products. Additionally, the review addresses the practical challenges of industrial implementation and explores future research directions for optimizing sensor functionality and scalability. The findings underscore the potential of polysaccharide-based intelligent packaging as a sustainable and effective alternative to conventional methods, paving the way for broader commercial adoption.

Sucrose-derived porous carbon catalyzed lignin depolymerization to obtain a product with application in type 2 diabetes mellitus

As the most important phenolic biopolymer in nature, lignin shows promising application potentialities in various bioactivities in vivo and in vitro, mainly including antioxidant, anti-inflammatory, hypolipidemic, and antidiabetic control. In this work, several carbon-based solid acids were synthesized to catalyze the fragmentation of organosolv lignin (OL). The generated lignin fragments, with controllable molecular weight and functional groups, were further evaluated for their application in the prevention and treatment of type 2 diabetes mellitus (T2DM). The results suggested that the urea-doped catalyst (SUPC) showed a more excellent catalytic performance in producing diethyl ether insoluble lignin (DEIL) and diethyl ether soluble lignin (DESL). In addition, the lignin fragments have a good therapeutic effect on the cell model of T2DM. Compared with the insulin resistance model, DEIL obtained by catalytic depolymerization of OL with SUPC could improve the glucose consumption of insulin-resistant cells. Moreover, low-concentration samples (50 μg/mL) can promote glucose consumption (19.7 mM) more than the traditional drug rosiglitazone (17.5 mM). This work demonstrates the prospect of depolymerized lignin for the prevention and treatment of T2DM and provides a new application field for lignin degradation products.

Cellulose-derived raw materials towards advanced functional transparent papers

Pulp and paper are gradually transforming from a traditional industry into a new green strategic industry. In parallel, cellulose-derived transparent paper is gaining ground for the development of advanced functional materials for light management with eco-friendly, high performance, and multifunctionality. This review focuses on methods and processes for the preparation of cellulose-derived transparent papers, highlighting the characterization of raw materials linked to responses to different properties, such as optical and mechanical properties. The applications in electronic devices, energy conversion and storage, and eco-friendly packaging are also highlighted with the objective to showcase the untapped potential of cellulose-derived transparent paper, challenging the prevailing notion that paper is merely a daily life product. Finally, the challenges and propose future directions for the development of cellulose-derived transparent paper are identified.

High-performance electrode materials of heteroatom-doped lignin-based carbon materials for supercapacitor applications

Supercapacitors are the preferred option for supporting renewable energy sources owing to many benefits, including fast charging, long life, high energy and power density, and saving energy. While electrode materials with environmentally friendly preparation, high performance, and low cost are important research directions of supercapacitors. At present, the growing global population and the increasingly pressing issue of environmental pollution have drawn the focus of numerous researchers worldwide to the development and utilization of renewable biomass resources. Lignin, a renewable aromatic polymer, has reserves second only to cellulose in nature. Ten million tonnes of industrial lignin are produced in pulp and paper mills annually, most of which are disposed of as waste or burned for fuel, seriously depleting natural resources and polluting the environment. One practical strategy to accomplish sustainable development is to employ lignin resources to create high-value materials. Based on the high carbon content and rich functional groups of lignin, the lignin-based carbon materials generated after carbonization treatment display specific electrochemical properties as electrode materials. Nevertheless, low electrochemical activity of untreated lignin precludes it from achieving its full potential for application in energy storage. Heteroatom doping is a common modification method that aims to improve the electrochemical performance of the electrode materials by optimizing the structure of the lignin, improving its pore structure and increasing the number of active sites on its surface. This paper aims to establish theoretical foundations for design, preparation, and optimizing the performance of heteroatom-doped lignin-based carbon materials, as well as for developing high-value-added lignin materials. The most reported the mechanism of supercapacitors, the doping process involving various types of heteroatoms, and the analysis of how heteroatoms affect the performance of lignin-based carbon materials are also detailed in this review.

Carbon-based single-atom catalysts derived from biomass: Fabrication and application

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.