Pristine cobalt humic acid xerogels embedded with ultrafine cobalt sulfide for enhanced and stable lithium-ion storage

The electrochemical performance of pristine metal-organic xerogels as anodes in lithium-ion batteries is reported for the first time. We propose a novel synthesis approach for the in situ generation of highly dispersed, ultrafine cobalt sulfide nanoparticles on humic acid gels (CoSHA). The CoS nanoparticles in CoSHA have an average diameter of approximately 3 nm. CoSHA electrodes demonstrate enhanced lithium storage capacity, delivering a capacity of 662 mAh g-1 at 0.1 A g-1. They also show stable long-term cycling performance, with no capacity decay after 900 cycles at 1.0 A g-1. Furthermore, our experiments indicate that the improved lithium-ion adsorption results from the oxygen-containing functional groups in humic acid and the ultrafine CoS active sites. This study offers a practical methodology for synthesizing ultrafine metal sulfides and new insights into using pristine gel-based electrodes for energy storage and conversion.

Biomass Waste Utilization as Nanocomposite Anodes through Conductive Polymers Strengthened SiO2/C from Streblus asper Leaves for Sustainable Energy Storages

Sustainable anode materials, including natural silica and biomass-derived carbon materials, are gaining increasing attention in emerging energy storage applications. In this research, we highlighted a silica/carbon (SiO2/C) derived from Streblus asper leaf wastes using a simple method. Dried Streblus asper leaves, which have plenty of biomass in Thailand, have a unique leaf texture due to their high SiO2 content. We can convert these worthless leaves into SiO2/C nanocomposites in one step, producing eco-materials with distinctive microstructures that influence electrochemical energy storage performance. Through nanostructured design, SiO2/C is thoroughly covered by a well-connected framework of conductive hybrid polymers based on the sodium alginate-polypyrrole (SA-PPy) network, exhibiting impressive morphology and performance. In addition, an excellent electrically conductive SA-PPy network binds to the SiO2/C particle surface through crosslinker bonding, creating a flexible porous space that effectively facilitates the SiO2 large volume expansion. At a current density of 0.3 C, this synthesized SA-PPy@Nano-SiO2/C anode provides a high specific capacity of 756 mAh g-1 over 350 cycles, accounting for 99.7% of the theoretical specific capacity. At the high current of 1 C (758 mA g-1), a superior sustained cycle life of over 500 cycles was evidenced, with over 93% capacity retention. The research also highlighted the potential for this approach to be scaled up for commercial production, which could have a significant impact on the sustainability of the lithium-ion battery industry. Overall, the development of green nanocomposites along with polymers having a distinctive structure is an exciting area of research that has the potential to address some of the key challenges associated with lithium-ion batteries, such as capacity degradation and safety concerns, while also promoting sustainability and reducing environmental impact.

Sustainable high-strength and dimensionally stable composites through in situ regulation and reconstitution of bamboo-derived lignin and hemicellulose contents

The development of modern construction and transportation industries demands increasingly high requirements for thin, lightweight, high-strength, and highly tough composite materials, such as metal carbides and concrete. Bamboo is a green, low-carbon, fast-growing, renewable, and biodegradable material with high strength and toughness. However, the density of its inner layer is low due to the functional gradient (the volume fraction of vascular bundles decreases from the outer layer to the inner layer), resulting in low performance, high compressibility, and significant amounts of bamboo waste. We utilized chemical and mechanical treatments of bamboo's low-density, low-strength inner layers to create lightweight, ultra-thin, high-strength, and high-toughness composites. The treatment included the partial removal of lignin and hemicellulose to alter the chemical components, followed by mechanical drying and hot pressing. The treated bamboo had 100.8 % higher tensile strength (150.35 MPa), 47.7 % higher flexural strength (97.67 MPa), and 132.0 % higher water resistance and was approximately 68.9 % thinner than the natural bamboo. The excellent physical and mechanical properties of the treated bamboo are attributed to the contraction of parenchyma cells during delignification, the interlocking due to the collapse of parenchyma cells during mechanical drying, and an increase in the density of hydrogen bonds between cellulose molecular chains during hot pressing. Our research provides a new strategy for obtaining sustainable, ultra-thin, lightweight, high-strength, and high-toughness composite materials from bamboo for construction and transportation applications.

Rational Biomimetic Construction of Lignin-based Carbon Nanozyme for Identification of Uric Acid in Human Urine

Nanozymes have made remarkable progress in the field of sensing assays by replacing native enzyme functions. However, it is still a challenge to rationally design active centers from molecular structure to enhance the catalytic performance and develop low-cost nanozymes. In this work, guided by the catalytic site of horseradish peroxidase (HRP), iron source and histidine were coupled to the main chain of aminated sodium lignosulfonate (SL) through the self-assembly biomimetic strategy to construct His-SL-Fe with peroxidase activity. The inherent functional groups and basic framework of aminated SL provide a robust environment and promote the formation of active sites. His-SL-Fe shows excellent robustness over multiple test cycles and has a strong affinity for the substrate compared to HRP. His-SL-Fe had been effectively integrated in the sensing system for catalytic detection of uric acid (UA) to achieve accurate recognition of UA in the range of 0.5-100 μM with the limit of detection as low as 0.18 μM. The recovery of human urine samples is in the range of 96.8%-106.1 % and the error is within 4 %. This work not only provides a new approach for the directed design of high-performance nanozymes, but also demonstrates promising ideas for the refined application of biomass resources.

Seaweed─Modification of Si by Natural Nitrogen-Doped Porous Biochar for High-Efficiency Lithium Batteries

Due to the porous structure and high electrical conductivity of carbon materials, lithium-ion batteries (LIBs) frequently employ carbon cladding to modify silicon anodes. However, the high cost and convoluted manufacturing process have prevented widespread use of carbon-based materials. Due to the abundance of seaweed (Gelidium amansii: GAm), there is a developing interest in seaweed's additional uses. We present, for the first time in lithium-ion batteries, the modification of silicon anodes by algal biomass carbon, which was thoroughly analyzed morphologically, structurally, and electrochemically. Seaweed's biomass carbon is porous and highly linked, making it ideal for evenly enclosing silicon nanoparticles and supplying the porous carbon skeleton with sufficient nitrogen after annealing. The Si@ self-encapsulated naturally nitrogen-doped biochar prepared from seaweed composites displayed reversible capacities of 1111.61 mAh g-1 after 500 cycles at a high current of 1 A g-1 and 714.08 mAh g-1 after 1000 cycles at the same current density.

Using algae in Li-ion batteries: A sustainable pathway toward greener energy storage

This paper reviews and analyzes the innovations and advances in using algae and their derivatives in different parts of Li-ion batteries. Applications in Li-ion battery anodes, electrolytes, binders, and separators were discussed. Algae provides a sustainable feedstock for different materials that can be used in Li-ion batteries, such as carbonaceous material, biosilica, biopolymers, and other materials that have unique micro- and nano-structures that act as biotemplates for composites structure design. Natural materials and biotemplates provided by algae have various advantages, such as electrochemical and thermal stability, porosity that allows higher storage capacity, nontoxicity, and other properties discussed in the paper. Results reveal that despite algae and its derivatives being a promising renewable feedstock for different applications in Li-ion batteries, more research is yet to be performed to evaluate its feasibility of being used in the industry.

A sustainable bio-based char as emerging electrode material for energy storage applications

In the last few years, extensive research efforts have been made to develop novel bio-char-based electrodes using different strategies starting from a variety of biomass precursors as well as applying different thermochemical conversion paths. In this regard, hydrothermal carbonization method is becoming a more prevalent option among conversion procedures even if pyrolysis remains crucial in converting biomass into carbonaceous materials. The main aim of this study is to develop an innovative supercapacitor electrode from spruce bark waste through a unique low-temperature technique approach, which proved to effectively eliminate the pyrolysis step. Consequently, a hybrid spruce-bark-graphene oxide compound (HySB) was obtained as electrode material for supercapacitors. When compared to a regularly used commercial electrode material, SLC1512P graphite (reference) with 150.3 µF cm-2 capacitance, the HySB has a substantially higher capacitive performance of 530.5 µF cm-2. In contrast to the reference, the HySB polarization resistance increases by two orders of magnitude at the stationary potential and by three orders of magnitude at the optimum potential, underlying that the superior performances of HySB extend beyond static conditions. The synthesis strategy provides an appropriate energy-efficient option for converting biomass into carbonaceous materials with meaningful properties suitable for energy storage applications.

Designing CoHCF@FeHCF Core-Shell Structures to Enhance the Rate Performance and Cycling Stability of Sodium-Ion Batteries

Prussian blue analogs are well suited for sodium-ion battery cathode materials due to their cheap cost and high theoretical specific capacity. Nax CoFe(CN)6 (CoHCF), one of the PBAs, has poor rate performance and cycling stability, while Nax FeFe(CN)6 (FeHCF) has better rate and cycling performance. The CoHCF@FeHCF core-shell structure is designed with CoHCF as the core material and FeHCF as the shell material to enhance the electrochemical properties. The successfully prepared core-shell structure leads to a significant improvement in the rate performance and cycling stability of the composite compared to the unmodified CoHCF. The composite sample of core-shell structure has a specific capacity of 54.8 mAh g-1 at high magnification of 20 C (1 C = 170 mA g-1 ). In terms of cycle stability, it has a capacity retention rate of 84.1% for 100 cycles at 1 C, and a capacity retention rate of 82.7% for 200 cycles at 5 C. Kinetic analysis shows that the composite sample with the core-shell structure has fast kinetic characteristics, and the surface capacitance occupation ratio and sodium-ion diffusion coefficient are higher than those of the unmodified CoHCF.

Effects of crystal structure and electronic properties on lithium storage performance of artificial graphite

Graphite is nowadays commonly used as the main component of anode materials of lithium-ion batteries (LIBs). It is essential to deeply investigate the fundamentals of artificial graphite to obtain excellent anode, especially crystal structure and electronic properties. In this report, a series of graphite with different crystal structure were synthesized and used for anodes of LIBs. Meanwhile, a concise method is designed to evaluate qualitatively the conductivity of lithium ion (σLi) and a profound mechanism of lithium storage was revealed in terms of solid state theory. The conductivity analysis demonstrates that the graphite with longer crystal plane and lower stacking layers possesses higher conductivity of electron (σe). On the other hand, lower initial charge/discharge voltage indicates the graphite with lower La and higher Lc holds higher conductivity of lithium ion (σLi). According to the solid state theory, graphite is considered to be a semi-conductor with zero activation energy, while the lithium intercalated graphite is like a conductor. The conductivity of graphite mainly depends on the σe, while the conductivity of lithium intercalated graphite can be determined by the summation of σe and σLi. In lower charge/discharge rate, Li+ have enough time to insert into the graphitic layer, making the special capacity of graphite primarily determined by σe. However, with the increase of charge/discharge rate, Li+ insertion/extraction will become more difficult, making σLi become the mainly factor of the graphite special capacity. Therefore, the graphite with longer crystal plane and lower stacking layers owns higher specific capacity under slow charge/discharge rate, the graphite with shorter crystal plane and higher stacking layers shows relatively lower specific capacity under rapid charge/discharge rate. These results provide important insights into the design and improvement of graphite's electrochemical performance.

A phthalocyanine-based porous organic polymer for a lithium-ion battery anode

Porous organic polymers (POPs) are a novel class of polymeric materials with high flexibility and designability for building structures. Herein, a phthalocyanine-based porous organic polymer (PcPOP) was constructed in situ on copper foil from H2Pc(ethynyl)4 [Pc(ethynyl)4 = 2(3),9(10),16(17),23(24)-tetra(ethynyl)phthalocyanine] by the coupling reaction. Benefiting from the uniformly distributed electron-rich nitrogen atoms in the Pc structure and the sp-hybridized carbons in the acetylenic linkage, Li intercalation in the porous organic polymer would be improved and stabilized. As a result, PcPOP showed remarkable electrochemical performance in lithium-ion batteries as the anode, including high specific capacity (a charge capacity of 1172 mA h g-1 at a current density of 150 mA g-1) and long cycling stability (a reversible capacity of 960.1 mA h g-1 can be achieved even after 600 cycles at a current density of 1500 mA g-1). The result indicates that the intrinsic doping of electron-rich sites of the building molecules is beneficial for the electrochemical performance of the porous organic polymer.

Interfacial Mo-S-C Bond with High Reversibility for Advanced Alkali-Ion Capacitors: Strategies for High-Throughput Production

The high-throughput scalable production of low-cost and high-performance electrode materials that work well under high power densities required in industrial application is full of challenges for the large-scale implementation of electrochemical technologies. Here, motivated by theoretical calculation that Mo-S-C heterojunction and sulfur vacancies can reduce the energy band gap, decrease the migration energy barrier, and improve the mechanical stability of MoS2 , the scalable preparation of inexpensive MoS2-x @CN is contrived by employing natural molybdenite as precursor, which is characteristic of high efficiency in synthesis process and energy conservation and the calculated costs are four orders of magnitude lower than MoS2 /C in previous work. More importantly, MoS2- x @CN electrode is endowed with impressive rate capability even at 5 A g-1 , and ultrastable cycling stability during almost 5000 cycles, which far outperform chemosynthesis MoS2 materials. Obtaining the full SIC cell assembled by MoS2- x @CN anode and carbon cathode, the energy/power output is high up to 265.3 W h kg-1 at 250 W kg-1 . These advantages indicate the huge potentials of the designed MoS2- x @CN and of mineral-based cost-effective and abundant resources as anode materials in high-performance AICs.

Recent Advances in Porous Carbon Materials as Electrodes for Supercapacitors

Porous carbon materials have demonstrated exceptional performance in various energy and environment-related applications. Recently, research on supercapacitors has been steadily increasing, and porous carbon materials have emerged as the most significant electrode material for supercapacitors. Nonetheless, the high cost and potential for environmental pollution associated with the preparation process of porous carbon materials remain significant issues. This paper presents an overview of common methods for preparing porous carbon materials, including the carbon-activation method, hard-templating method, soft-templating method, sacrificial-templating method, and self-templating method. Additionally, we also review several emerging methods for the preparation of porous carbon materials, such as copolymer pyrolysis, carbohydrate self-activation, and laser scribing. We then categorise porous carbons based on their pore sizes and the presence or absence of heteroatom doping. Finally, we provide an overview of recent applications of porous carbon materials as electrodes for supercapacitors.

Turbostratic Lattice and Electronegativity Modification Jointly Enabled an Ultra-High-Rate and Long-Lived Carbon Anode for Potassium-Ion Batteries

Potassium-ion batteries (PIBs) are considered as a promising technology alternative to lithium-ion batteries due to more abundance of potassium than lithium and a lower redox potential of K/K⁺ than that of Na/Na⁺. The critical limitation in PIBs is the electrode with poor rate capability and cycling stability induced by the sluggish reaction kinetics and large volume change during potassiation and depotassiation. In this work, we report a turbostratic lattice iodine-doped carbon (TLIC) nanosheet as an advanced innovative anode for PIBs displaying fast charge/discharge and electrode stability. The turbostratic lattice caused by doping of large-sized iodine and the unique charge transfer between iodine/carbon atoms creates more active sites and a shorter transport distance for K ions, improves the electrochemical activity, promotes rapid ion diffusion, and enhances pseudocapacitive behavior. The TLIC exhibits a high capacity of 433.5 mAh g^-1 at 50 mA g^-1, an ultrahigh rate capability of 162.1 mAh g^-1 at 20 A g^-1, and an excellent capacity retention of ∼96% (206 mAh g^-1) after 4000 cycles. The combination of turbostratic lattice and pseudocapactive storage is an effective approach to designing carbon electrodes with the transformational performance of high capacity, rate performance, and long lifetime for practical applications of PIBs.

Porous Carbon with Alumina Coating Nanolayer Derived from Biomass and the Enhanced Electrochemical Performance as Stable Anode Materials

With the ever-increasing world population, the energy produced from green, environmentally friendly approaches is in high demand. In this work, we proposed a green and cost-effective strategy for synthesizing a porous carbon electrode decorated with alumina oxide (Al₂O₃) from cherry blossom leaves using the pyrolysis method followed by a sol-gel method. An Al₂O₃-coating nano-layer (4-6 nm) is formed on the porous carbon during the composition fabrication, which further adversely affects battery performance. The development of a simple rich-shell-structured C@Al₂O₃ nanocomposite anode is expected to achieve stable electrochemical performances as lithium storage. A significant contributing factor to enhanced performance is the structure of the rich-shell material, which greatly enhances conductivity and stabilizes the solid-electrolyte interface (SEI) film. In the battery test assembled with composite C@Al₂O₃ electrode, the specific capacity is 516.1 mAh g^-1 at a current density of 0.1 A g^-1 after 200 cycles. The average discharge capacity of carbon is 290 mAh g^-1 at a current density of 1.0 A g^-1. The present study proposes bioinspired porous carbon electrode materials for improving the performance of next-generation lithium-ion batteries.

Defect Engineering of Disordered Carbon Anodes with Ultra-High Heteroatom Doping Through a Supermolecule-Mediated Strategy for Potassium-Ion Hybrid Capacitors

Amorphous carbons are promising anodes for high-rate potassium-ion batteries. Most low-temperature annealed amorphous carbons display unsatisfactory capacities. Heteroatom-induced defect engineering of amorphous carbons could enhance their reversible capacities. Nevertheless, most lignocellulose biomasses lack heteroatoms, making it a challenge to design highly heteroatom-doped carbons (> 10 at%). Herein, we report a new preparation strategy for amorphous carbon anodes. Nitrogen/sulfur co-doped lignin-derived porous carbons (NSLPC) with ultra-high nitrogen doping levels (21.6 at% of N and 0.8 at% of S) from renewable lignin biomacromolecule precursors were prepared through a supramolecule-mediated pyrolysis strategy. This supermolecule/lignin composite decomposes forming a covalently bonded graphitic carbon/amorphous carbon intermediate product, which induces the formation of high heteroatom doping in the obtained NSLPC. This unique pyrolysis chemistry and high heteroatom doping of NSLPC enable abundant defective active sites for the adsorption of K+ and improved kinetics. The NSLPC anode delivered a high reversible capacity of 419 mAh g‒1 and superior cycling stability (capacity retention of 96.6% at 1 A g‒1 for 1000 cycles). Potassium-ion hybrid capacitors assembled by NSLPC anode exhibited excellent cycling stability (91% capacity retention for 2000 cycles) and a high energy density of 71 Wh kg-1 at a power density of 92 W kg-1.

Spectator-metal-ion-guided redox-dominant cobalt oxyhydroxide as a high-performance supercapacitor

The ability of spectator metal ions such as vanadium to enhance the electrochemical performance of supercapacitors has been explained. Vanadium-incorporated CoO(OH) combined with NiMn-layered double hydroxide (LDH) yields a specific capacitance of 1700 F g^-1 at 1 A g^-1 with 96% retention after 5000 cycles. The assembled asymmetric supercapacitor exhibits an energy density of 45.93 W h Kg^-1 and a power density of 752 W kg^-1@1 A g^-1.

Sustainable Conversion of Harmful Algae Biomass into a CO2 Reduction Electrocatalyst for Two-Fold Carbon Utilization

Harmful algae blooms (HABs) frequently occur all over the world and cause great harm to the environment, human health, and aquatic ecosystems. However, owing to their great growth rate and large nutrient intake capacity, algae can enrich a large amount of carbon (CO₂) and nutritional elements (N and P) in their biomass. Thus, this could be applied as a robust approach to battle global warming and water eutrophication if the harmful algae biomass was effectively harvested and utilized. Herein, we propose a thermochemical approach to convert algae biomass into a nitrogen-doped electrocatalyst for CO₂ reduction. The as-synthesized carbon catalyst exhibits a favorable electrochemical CO₂ reduction activity. The key drivers of the environmental impacts in the thermochemical conversion approach with a comparison with the commonly used landfilling approach are identified with life cycle assessment. The former presents much lower environmental burdens in terms of impacts such as freshwater/terrestrial ecotoxicity and human toxicity than the latter. Moreover, if the thermochemical conversion process was successfully applied for biomass conversion worldwide, 2.17 × 10⁸ tons of CO₂-eq, 8.42 × 10⁶ tons of N, and 1.21 × 10⁶ tons of P could be removed from the global carbon and other element cycles. Meanwhile, the thermochemical approach is also similar to landfilling in terms of costs. The results from this work provide a brand-new perspective for achieving twofold CO₂ utilization and efficiently battling harmful algae blooms.

Biomass-Derived Carbon Anode for High-Performance Microbial Fuel Cells

: Although microbial fuel cells (MFCs) have been developed over the past decade, they still have a low power production bottleneck for practical engineering due to the ineffective interfacial bioelectrochemical reaction between exoelectrogens and anode surfaces using traditional carbonaceous materials. Constructing anodes from biomass is an effective strategy to tackle the current challenges and improve the efficiency of MFCs. The advantage features of these materials come from the well-decorated aspect with an enriched functional group, the turbostratic nature, and porous structure, which is important to promote the electrocatalytic behavior of anodes in MFCs. In this review article, the three designs of biomass-derived carbon anodes based on their final products (i.e., biomass-derived nanocomposite carbons for anode surface modification, biomass-derived free-standing three-dimensional carbon anodes, and biomass-derived carbons for hybrid structured anodes) are highlighted. Next, the most frequently obtained carbon anode morphologies, characterizations, and the carbonization processes of biomass-derived MFC anodes were systematically reviewed. To conclude, the drawbacks and prospects for biomass-derived carbon anodes are suggested.

A lignin-derived flexible porous carbon material for highly efficient polyselenide and sodium regulation

Low-cost and sustainable sodium-selenium (Na-Se) batteries are promising energy storage media for the advancement of electromobility and large-scale energy storage. However, the sluggish kinetics of Se cathodes and the unpredictable metal electrodeposition of Na at the anode remain critical challenges. In this work, we reveal the catalytic effect of atomic Fe on the conversion of polyselenides (SPSs) to Na₂Se by density functional theory (DFT) calculations. Then, we prepare a lignin-derived flexible porous carbon matrix loaded with atomic Fe (Fe-BC/rGO, BC: lignin-derived porous carbon material; rGO: reduced graphene oxide) as a Se host to further verify the DFT calculation results. Due to the encapsulation of Se into the porous carbon matrix, the catalytic effect of atomic Fe on the conversion of SPSs to Na₂Se and the continuous electron/ion transportation path, the prepared Se@Fe-BC/rGO cathode can deliver a high reversible capacity of 213 mA h g^-1 at 2 A g^-1, which is much better than the electrochemical performance of a Se cathode without atomic Fe loading (Se@BC/rGO). In addition, we further reveal the advantageous effect of the presence of the Fe-BC/rGO film in regulating the interfacial Na electrodeposition at the anode. Due to the porous structure and the catalytic effect of atomic Fe, a very low nucleation overpotential of 15.3 mV is achieved at a current density of 1 mA cm^-2, which is much lower than that of the BC/rGO film. Therefore, this work provides a low-cost and sustainable strategy for simultaneously solving the challenges of the Se cathode and the Na metal anode for future Na-Se batteries.

Efficient Visible-Light Photocatalysis and Antibacterial Activity of TiO2-Fe3C-Fe-Fe3O4/Graphitic Carbon Composites Fabricated by Catalytic Graphitization of Sucrose Using Natural Ilmenite

Dyes in wastewater are a serious problem that needs to be resolved. Adsorption coupled photocatalysis is an innovative technique used to remove dyes from contaminated water. Novel composites of TiO₂-Fe₃C-Fe-Fe₃O₄ dispersed on graphitic carbon were fabricated using natural ilmenite sand as the source of iron and titanium, and sucrose as the carbon source, which were available at no cost. Synthesized composites were characterized by X-ray diffractometry (XRD), Raman spectroscopy, transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), X-ray fluorescence spectroscopy (XRF), and diffuse reflectance UV-visible spectroscopy (DRS). Arrangement of nanoribbons of graphitic carbon with respect to the nanomaterials was observed in TEM images, revealing the occurrence of catalytic graphitization. Variations in the intensity ratio (I _D/I _G), L _a and L _D, calculated from data obtained from Raman spectroscopy suggested that the level of graphitization increased with an increased loading of the catalysts. SEM images show the immobilization of nanoplate microballs and nanoparticles on the graphitic carbon matrix. The catalyst surface consists of Fe³⁺ and Ti⁴⁺ as the metal species, with V, Mn, and Zr being the main impurities. According to DRS spectra, the synthesized composites absorb light in the visible region efficiently. Fabricated composites effectively adsorb methylene blue via π-π interactions, with the absorption capacities ranging from 21.18 to 45.87 mg/g. They were effective in photodegrading methylene blue under sunlight, where the rate constants varied in the 0.003-0.007 min^-1 range. Photogenerated electrons produced by photocatalysts captured by graphitic carbon produce O₂ ^•- radicals, while holes generate OH^• radicals, which effectively degrade methylene blue molecules. TiO₂-Fe₃C-Fe-Fe₃O₄/graphitic carbon composites inhibited the growth of Escherichia coli (69%) and Staphylococcus aureus (92%) under visible light. Synthesized novel composites using natural materials comprise an ecofriendly, cost-effective solution to remove dyes, and they were effective in inhibiting the growth of Gram-negative and Gram-positive bacteria.

Stimuli-Responsive Electrochemical Energy Storage Devices

Electrochemical energy storage (EES) devices have been swiftly developed in recent years. Stimuli-responsive EES devices that respond to different external stimuli are considered the most advanced EES devices. The stimuli-responsive EES devices enhanced the performance and applications of the EES devices. The capability of the EES devices to respond to the various external stimuli due to produced advanced EES devices that distinguished the best performance and interactions in different situations. The stimuli-responsive EES devices have responsive behavior to different external stimuli including chemical compounds, electricity, photons, mechanical tensions, and temperature. All of these advanced responsiveness behaviors have originated from the functionality and specific structure of the EES devices. The multi-responsive EES devices have been recognized as the next generation of stimuli-responsive EES devices. There are two main steps in developing stimuli-responsive EES devices in the future. The first step is the combination of the economical, environmental, electrochemical, and multi-responsiveness priorities in an EES device. The second step is obtaining some advanced properties such as biocompatibility, flexibility, stretchability, transparency, and wearability in novel stimuli-responsive EES devices. Future studies on stimuli-responsive EES devices will be allocated to merging these significant two steps to improve the performance of the stimuli-responsive EES devices to challenge complicated situations.

Electrochemical Performance of Graphene Oxide/Black Arsenic Phosphorus/Carbon Nanotubes as Anode Material for LIBs

As a new two-dimensional material, black arsenic phosphorus (B-AsP) has emerged as a promising electrode for lithium-ion batteries (LIBs) due to its large theoretical capacity and ability to absorb large amounts of Li atoms. However, the poor electronic conductivity and large volume expansion during the lithiation/delithiation process have largely impeded the development of B-AsP electrodes. In this study, graphene oxide (GO)/B-AsP/carbon nanotubes (CNTs) with remarkable lithium-storage property were fabricated via CVD and ultrasound-assisted method. The electrochemical behavior of the GO/B-AsP/CNTs was investigated as an anode in lithium-ion batteries. From the results, as a new-type anode for LIBs, GO/B-AsP/CNTs composite demonstrated a stable capacity of 1286 and 339 mA h g⁻¹ at the current density of 0.1 and 1 A g⁻¹, respectively. The capacity of GO/B-AsP/CNTs was 693 mA h g⁻¹ after 50 cycles, resulting in capacity retention of almost 86%. In addition, the stable P-C and As-C bonds were formed between B-AsP, GO, and CNTs. Thus, volume expansion of B-AsP was alleviated and the capacity was increased due to the confining effect of GO and CNTs.

Biomass-derived porous carbon with high drug adsorption capacity undergoes enzymatic and chemical degradation

Degradability is a key safety issue when choosing materials for biomedical applications and environmental protection. This factor greatly limits the application of porous carbon in these areas due to the inert and stable nature of carbon network. In this work, this conflict could be well-resolved by rational designing a mesoporous carbon (MC) with biomass as a carbon source. The retained oxygen-containing species simultaneously increase drug adsorption capacity and the degradability of MC. The maximum adsorption quantity for doxorubicin over MC can reach 395.3 mg/g, about 3-fold over carbon nanotubes. The detailed analysis reveals that the degradation of MC occurs via a radical mediated oxidation process. The high electron density feature of MC facilitates the electrophilic addition reaction in the presence of HO. During this process, the carbon network is gradually degraded into fragments, carbon nanodots and ultimately to CO₂. This work opens up a new way to fabricate degradable porous materials and provides a promising material for the practical application in biomedical and environmental field.

Seaweed’s Role in Energetic Transition—From Environmental Pollution Challenges to Enhanced Electrochemical Devices

Simple Summary

Earth is currently facing the effects of climate change in all environmental ecosystems; this, together with pollution, is the cause of species extinction and biodiversity loss. Thus, it is vital to take actions to mitigate and decrease the release of greenhouse gases to the atmosphere. The emergence of energetic transition from fossil fuels to greener energies is clearly defined in the United Nations 2030 agenda. Although this transition endorses the ambitious goal to supply greener energy for all developed societies, the increased demand for the minerals essential to develop cleaner energetic technologies has highlighted several economic and environmental issues. Currently, these minerals are mainly obtained by mining activities that generate high levels of soil and water pollution, coupled with the intensive use of water and hazardous gas release. On the other hand, the exponential increase of electronic waste derived from end-of-life electronic equipment is already raising environmental concerns due to heavy metal contamination as a result of their disposal. Thus, it is vital to develop sustainable and efficient strategies to mitigate energetic transition environmental footprints. This review highlights the use of seaweed biomass for toxic mineral bioremediation, recycling, and as an alternative material for greener energy-storage device development.

Abstract

Resulting from the growing human population and the long dependency on fossil-based energies, the planet is facing a critical rise in global temperature, which is affecting all ecosystem networks. With a growing consciousness this issue, the EU has defined several strategies towards environment sustainability, where biodiversity restoration and preservation, pollution reduction, circular economy, and energetic transition are paramount issues. To achieve the ambitious goal of becoming climate-neutral by 2050, it is vital to mitigate the environmental footprint of the energetic transition, namely heavy metal pollution resulting from mining and processing of raw materials and from electronic waste disposal. Additionally, it is vital to find alternative materials to enhance the efficiency of energy storage devices. This review addresses the environmental challenges associated with energetic transition, with particular emphasis on the emergence of new alternative materials for the development of cleaner energy technologies and on the environmental impacts of mitigation strategies. We compile the most recent advances on natural sources, particularly seaweed, with regard to their use in metal recycling, bioremediation, and as valuable biomass to produce biochar for electrochemical applications.

Highly graphitic porous carbon prepared via K2FeO4-assisted KOH activation for supercapacitors

K2FeO4-assisted KOH activation can improve the graphitization and porous structure to enhance the electrochemical performance of carbon materials.

Facile synthesis of carbon and oxygen vacancy co-modified TiNb6O17 as an anode material for lithium-ion batteries

Titanium niobium oxides (TNOs), benefitting from their large specific capacity and Wadsley–Roth shear structure, are competitive anode materials for high-energy density and high-rate lithium-ion batteries. Herein, carbon and oxygen vacancy co-modified TiNb₆O₁₇ (A-TNO) was synthesized through a facile sol–gel reaction with subsequent heat treatment and ball-milling. Characterizations indicated that A-TNO is composed of nanosized primary particles, and the carbon content is about 0.7 wt%. The nanoparticles increase the contact area of the electrode and electrolyte and shorten the lithium-ion diffusion distance. The carbon and oxygen vacancies decrease the charge transfer resistance and enhance the Li-ion diffusion coefficient of the obtained anode material. As a result of these advantages, A-TNO exhibits excellent rate performance (208 and 177 mA h g⁻¹ at 10C and 20C, respectively). This work reveals that A-TNO possesses good electrochemical performance and has a facile preparation process, thus A-TNO is believed to be a potential anode material for large-scale applications.

Carbon and oxygen vacancy co-modified TiNb₆O₁₇ is synthesized through a facile sol–gel reaction. It possesses good electrochemical performance, thus is believed to be a potential anode material for large-scale applications.

Review on upgrading organic waste to value-added carbon materials for energy and environmental applications

Value-added materials such as biochar and activated carbon that are produced using thermo-chemical conversion of organic waste have gained an emerging interest for the application in the fields of energy and environment because of their low cost and unique physico-chemical properties. Organic waste-derived materials have multifunctional abilities in the field of environment for capturing greenhouse gases and remediation of contaminated soil and water as well as in the field of energy storage and conversion. This review critically evaluates and discusses the current thermo-chemical approaches for upgrading organic waste to value-added carbon materials, performance enhancement of these materials via activation and/or surface modification, and recent research findings related to energy and environmental applications. Moreover, this review provides detailed guidelines for preparing high-performance organic waste-derived materials and insights for their potential applications. Key challenges associated with the sustainable management of organic waste for ecological and socio-economic benefits and potential solutions are also discussed.

Biomass-Derived Carbon Materials: Controllable Preparation and Versatile Applications

Biomass-derived carbon materials (BCMs) are encountering the most flourishing moment because of their versatile properties and wide potential applications. Numerous BCMs, including 0D carbon spheres and dots, 1D carbon fibers and tubes, 2D carbon sheets, 3D carbon aerogel, and hierarchical carbon materials have been prepared. At the same time, their structure-property relationship and applications have been widely studied. This paper aims to present a review on the recent advances in the controllable preparation and potential applications of BCMs, providing a reference for future work. First, the chemical compositions of typical biomass and their thermal degradation mechanisms are presented. Then, the typical preparation methods of BCMs are summarized and the relevant structural management rules are discussed. Besides, the strategies for improving the structural diversity of BCMs are also presented and discussed. Furthermore, the applications of BCMs in energy, sensing, environment, and other areas are reviewed. Finally, the remaining challenges and opportunities in the field of BCMs are discussed.

Constructing N-doping biomass-derived carbon with hierarchically porous architecture to boost fast reaction kinetics for higfh-performance lithium storage

Active biomass-derived carbons are brought into focus on boosting high-performance lithium storage. However, their low electric conductivity and poor ion diffusion kinetics during the lithium storage reactions remain confusing topics. This study demonstrates a novel and effective strategy of dual system activation process to construct the nitrogen-doped biomass-derived carbon with hierarchically porous architecture (HNBC), which is composed of the three-dimensional porous networks connected by carbon nanorods and the flake-like edges constructed by carbon nanosheets. A large amount of nitrogen doping can improve the conductivity and facilitate the charge transfer during charging/discharging, while the hierarchically porous structure can decrease the diffusion path for lithium-ion transport, enabling fast diffusion and charge-transfer dynamics. The HNBC electrode displays a high lithium-ion storage capacity of above 1392 mAh g^-1 at 0.1 A g^-1 and superior stability. Moreover, the assembled asymmetric lithium-ion capacitor exhibits excellent cycling stability and delivers a high power density of 225 W kg^-1 with an energy density of 186.31 W h kg^-1. This dual system activation strategy may inspire the reasonable design of new-generation progressive carbon-based electrodes for high-performance lithium storage devices.

Correlating the chemical properties and bioavailability of dissolved organic matter released from hydrochar of walnut shells

Large amounts of lignocellulosic biomass are discarded, whereas the carbon source of sewage is deficient. This situation greatly impairs the efficiency of wastewater treatment. To address this concern, we evaluate the feasibility of using hydrochar as a potential carbon source by systematically investigating the effects of hydrothermal carbonization (HTC) conditions on the composition, content, and chemical structure of dissolved organic matter (DOM) released from hydrochar. Results show that the most important factor that affects the properties of hydrochar and DOM is temperature, followed by heating rate. Under optimal HTC conditions, the growth of Bacillus subtilis increased by 18.32% in hydrochar aqueous solution in comparison with the 6.64% growth of the untreated biomass group. Excitation emission matrix-parallel factor analysis and UV-vis analyses confirm that the DOM released by hydrochar produced at a low temperature mainly contains protein substances, which promote the growth of microorganisms. The DOM released by hydrochar at a high temperature mainly contains humic substances with an aromatic structure; such substances are toxic to microorganisms. This study demonstrates that hydrochar obtained under optimized conditions can be a potential carbon source of wastewater treatment plants.

Characterization of lithium zinc titanate doped with metal ions as anode materials for lithium ion batteries

With the aim of improving the ionic and electronic conductivities of Li₂ZnTi₃O₈ for high performance lithium ion battery applications, Li₂Zn_0.9M_0.1Ti₃O₈ (M = Li⁺, Cu²⁺, Al³⁺, Ti⁴⁺, Nb⁵⁺, Mo⁶⁺) compounds are successfully fabricated using facile high temperature calcination at 800 °C. Physical characterization and lithium ion reversible storage demonstrate that Zn-site substitution by multivalent metal ions is beneficial for improving the migration rate of ions and electrons of Li₂ZnTi₃O₈. X-ray diffraction analysis and scanning electron microscopy reveal that the crystal structure and microscopic morphology of bare Li₂ZnTi₃O₈ do not change by introducing a small amount of foreign metal ions. As a result, Li₂Zn_0.9Nb_0.1Ti₃O₈ retains a reversible capacity as high as 198 mA h g^-1 at the end of the 500th cycle among all samples. Even when cycled at high temperatures, Li₂Zn_0.9Nb_0.1Ti₃O₈ still maintains excellent reversible discharge capacities of 210 mA h g^-1 and 196 mA h g^-1 at 1000 mA g^-1 for the 100th cycle at 50 °C and 60 °C, respectively. All the conclusions indicate that Li₂Zn_0.9Nb_0.1Ti₃O₈ is a high-performance anode material for large-scale energy storage devices.

Lithium-Ion Capacitors: A Review of Design and Active Materials

Lithium-ion capacitors (LICs) have gained significant attention in recent years for their increased energy density without altering their power density. LICs achieve higher capacitance than traditional supercapacitors due to their hybrid battery electrode and subsequent higher voltage. This is due to the asymmetric action of LICs, which serves as an enhancer of traditional supercapacitors. This culminates in the potential for pollution-free, long-lasting, and efficient energy-storing that is required to realise a renewable energy future. This review article offers an analysis of recent progress in the production of LIC electrode active materials, requirements and performance. In-situ hybridisation and ex-situ recombination of composite materials comprising a wide variety of active constituents is also addressed. The possible challenges and opportunities for future research based on LICs in energy applications are also discussed.