Antimony/Porous Biomass Carbon Nanocomposites as High‐Capacity Anode Materials for Sodium‐Ion Batteries

Antimony/porous biomass carbon nanocomposites have been prepared by a chemical reduction method and applied as anodes for sodium‐ion batteries. The porous biomass carbon derived from a black fungus had a large Brunauer–Emmett–Teller (BET) surface area of 2233 m² g⁻¹ in which antimony nanoparticles were uniformly distributed in the porous carbon. The as‐prepared antimony/porous biomass carbon nanocomposites exhibited a high reversible sodium storage capacity of 567 mA h g⁻¹ at a current density of 100 mA g⁻¹, extended cycling stability, and good rate capability.     

Hierarchical Activated Mesoporous Phenolic‐Resin‐Based Carbons for Supercapacitors

A series of hierarchical activated mesoporous carbons (AMCs) were prepared by the activation of highly ordered, body‐centered cubic mesoporous phenolic‐resin‐based carbon with KOH. The effect of the KOH/carbon‐weight ratio on the textural properties and capacitive performance of the AMCs was investigated in detail. An AMC prepared with a KOH/carbon‐weight ratio of 6:1 possessed the largest specific surface area (1118 m² g^?1), with retention of the ordered mesoporous structure, and exhibited the highest specific capacitance of 260 F g^?1 at a current density of 0.1 A g^?1 in 1 M H₂SO₄ aqueous electrolyte. This material also showed excellent rate capability (163 F g^?1 retained at 20 A g^?1) and good long‐term electrochemical stability. This superior capacitive performance could be attributed to a large specific surface area and an optimized micro‐mesopore structure, which not only increased the effective specific surface area for charge storage but also provided a favorable pathway for efficient ion transport.     

Non‐Covalent Functionalization of Graphene with Bisphenol A for High‐Performance Supercapacitors

The reduced graphene oxide (RGO)/bisphenol A (BPA) composites were prepared by an adsorption‐reduction method. The composites are characterized by X‐ray diffraction (XRD), UV‐vis, thermogravimetric (TG) analysis, field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM). The results confirm that BPA is adsorbed on the basal plane of RGO by π‐π stacking interaction. Furthermore, the electrochemical behaviors were evaluated by cyclic voltammetry, galvanostatic charge/discharge techniques and electrochemical impedance spectroscopy (EIS). The results show that the RGO/BPA nanocomposites exhibit ultrahigh specific capacitance of 466 F·g^?1 at a current density of 1 A·g^?1, excellent rate capability (more than 81% retention at 10 A·g^?1 relative to 1 A·g^?1) and superior cycling stability (90% capacitance decay after 4000 cycles). Consequently, the RGO/BPA nanocomposites can be regarded as promising electrode materials for supercapacitor applications.     

A Multi‐Wall Sn/SnO2@Carbon Hollow Nanofiber Anode Material for High‐Rate and Long‐Life Lithium‐Ion Batteries

Multi‐wall Sn/SnO₂@carbon hollow nanofibers evolved from SnO₂ nanofibers are designed and programable synthesized by electrospinning, polypyrrole coating, and annealing reduction. The synthesized hollow nanofibers have a special wire‐in‐double‐wall‐tube structure with larger specific surface area and abundant inner spaces, which can provide effective contacting area of electrolyte with electrode materials and more active sites for redox reaction. It shows excellent cycling stability by virtue of effectively alleviating pulverization of tin‐based electrode materials caused by volume expansion. Even after 2000 cycles, the wire‐in‐double‐wall‐tube Sn/SnO₂@carbon nanofibers exhibit a high specific capacity of 986.3 mAh g^?1 (1 A g^?1) and still maintains 508.2 mAh g^?1 at high current density of 5 A g^?1. This outstanding electrochemical performance suggests the multi‐wall Sn/SnO₂@ carbon hollow nanofibers are great promising for high performance energy storage systems.     

In Situ Growth of MnO2 Nanosheets on N‐Doped Carbon Nanotubes Derived from Polypyrrole Tubes for Supercapacitors

Nitrogen‐doped porous carbon nanotubes@MnO₂ (N‐CNTs@MnO₂) nanocomposites are prepared through the in situ growth of MnO₂ nanosheets on N‐CNTs derived from polypyrrole nanotubes (PNTs). Benefiting from the synergistic effects between N‐CNTs (high conductivity and N doping level) and MnO₂ nanosheets (high theoretical capacity), the as‐prepared N‐CNTs@MnO₂‐800 nanocomposites show a specific capacitance of 219 F g^?1 at a current density of 1.0 A g^?1, which is higher than that of pure MnO₂ nanosheets (128 F g^?1) and PNTs (42 F g^?1) in 0.5 m Na₂SO₄ solution. Meanwhile, the capacitance retention of 86.8 % (after 1000 cycles at 10 A g^?1) indicates an excellent electrochemical performance of N‐CNTs@MnO₂ prepared in this work.     

Iridium‐Catalyst‐Based Autonomous Bubble‐Propelled Graphene Micromotors with Ultralow Catalyst Loading

A novel concept of an iridium‐based bubble‐propelled Janus‐particle‐type graphene micromotor with very high surface area and with very low catalyst loading is described. The low loading of Ir catalyst (0.54 at %) allows for fast motion of graphene microparticles with high surface area of 316.2 m² g^?1. The micromotor was prepared with a simple and scalable method by thermal exfoliation of iridium‐doped graphite oxide precursor composite in hydrogen atmosphere. Oxygen bubbles generated from the decomposition of hydrogen peroxide at the iridium catalytic sites provide robust propulsion thrust for the graphene micromotor. The high surface area and low iridium catalyst loading of the bubble‐propelled graphene motors offer great possibilities for dramatically enhanced cargo delivery.     

The preparation of covalent triazine‐based framework via Friedel‐Crafts reaction of 2,4,6‐trichloro‐1,3,5‐triazine with N,N′‐diphenyl‐N,N′‐di(m‐tolyl)benzidine for capturing and sensing to iodine

The covalent triazine‐based framework (TDPDB) has been prepared by Friedel‐Crafts polymerization reaction of N,N′‐diphenyl‐N,N′‐di(m‐tolyl)benzidine (DPDB) with 2,4,6‐trichloro‐1,3,5‐triazine (TCT) catalyzed by methanesulfonic acid. The yield of the reaction (94.85%) is very high. TDPDB was provided with Brunauer‐Emmett‐Teller specific surface area of 592.18 m² g^?1 and pore volume of 0.5241 cm³ g^?1. TDPDB demonstrated an excellent capacity for capturing iodine (3.93 g g^?1) and an outstanding ability to fluorescent sensing to iodine with Ksv of 5.83 × 10⁴ L mol^?1. It also showed high fluorescent sensing sensitivity to picric acid.     

MoS2 Nanoflowers with Expanded Interlayers as High‐Performance Anodes for Sodium‐Ion Batteries

MoS₂ nanoflowers with expanded interlayer spacing of the (002) plane were synthesized and used as high‐performance anode in Na‐ion batteries. By controlling the cut‐off voltage to the range of 0.4–3 V, an intercalation mechanism rather than a conversion reaction is taking place. The MoS₂ nanoflower electrode shows high discharge capacities of 350 mAh g^?1 at 0.05 A g^?1, 300 mAh g^?1 at 1 A g^?1, and 195 mAh g^?1 at 10 A g^?1. An initial capacity increase with cycling is caused by peeling off MoS₂ layers, which produces more active sites for Na⁺ storage. The stripping of MoS₂ layers occurring in charge/discharge cycling contributes to the enhanced kinetics and low energy barrier for the intercalation of Na⁺ ions. The electrochemical reaction is mainly controlled by the capacitive process, which facilitates the high‐rate capability. Therefore, MoS₂ nanoflowers with expanded interlayers hold promise for rechargeable Na‐ion batteries.     

Advanced Catalytic Performance of Au–Pt Double‐Walled Nanotubes and Their Fabrication through Galvanic Replacement Reaction

Bimetallic tubular nanostructures have been the focus of intensive research as they have very interesting potential applications in various fields including catalysis and electronics. In this paper, we demonstrate a facile method for the fabrication of Au–Pt double‐walled nanotubes (Au–Pt DWNTs). The DWNTs are fabricated through the galvanic displacement reaction between Ag nanowires and various metal ions, and the Au–Pt DWNT catalysts exhibit high active catalytic performances toward both methanol electro‐oxidation and 4‐nitrophenol (4‐NP) reduction. First, they have a high electrochemically active surface area of 61.66 m² g^?1, which is close to the value of commercial Pt/C catalysts (64.76 m² g^?1), and the peak current density of Au–Pt DWNTs in methanol oxidation is recorded as 138.25 mA mg^?1, whereas those of Pt nanotubes, Au/Pt nanotubes (simple mixture), and commercial Pt/C are 24.12, 40.95, and120.65 mA mg^?1, respectively. The Au–Pt DWNTs show a markedly enhanced electrocatalytic activity for methanol oxidation compared with the other three catalysts. They also show an excellent catalytic performance in comparison with common Au nanotubes for 4‐nitrophenol (4‐NP) reduction. The attractive performance exhibited by these prepared Au–Pt DWNTs can be attributed to their unique structures, which make them promising candidates as high‐performance catalysts.     

Biomass‐Derived Porous Carbon with Micropores and Small Mesopores for High‐Performance Lithium–Sulfur Batteries

Biomass‐derived porous carbon BPC‐700, incorporating micropores and small mesopores, was prepared through pyrolysis of banana peel followed by activation with KOH. A high specific BET surface area (2741 m² g^?1), large specific pore volume (1.23 cm³ g^?1), and well‐controlled pore size distribution (0.6–5.0 nm) were obtained and up to 65 wt % sulfur content could be loaded into the pores of the BPC‐700 sample. When the resultant C/S composite, BPC‐700‐S65, was used as the cathode of a Li–S battery, a large initial discharge capacity (ca. 1200 mAh g^?1) was obtained, indicating a good sulfur utilization rate. An excellent discharge capacity (590 mAh g^?1) was also achieved for BPC‐700‐S65 at the high current rate of 4 C (12.72 mA cm^?2), showing its extremely high rate capability. A reversible capacity of about 570 mAh g^?1 was achieved for BPC‐700‐S65 after 500 cycles at 1 C (3.18 mA cm^?2), indicating an outstanding cycling stability.     

Pyrolysis of Animal Bones with Vitamin B12: A Facile Route to Efficient Transition Metal–Nitrogen–Carbon (TM‐N‐C) Electrocatalysts for Oxygen Reduction

By pyrolyzing cattle bones, hierarchical porous carbon (HPC) networks with a high surface area (2520 m² g^?1) and connected pores were prepared at a low cost and large scale. Subsequent co‐pyrolysis of HPC with vitamin B12 resulted in the formation of three‐dimensional (3D) hierarchically structured porous cobalt–nitrogen–carbon (Co‐N‐HPC) electrocatalysts with a surface area as high as 859 m² g^?1 as well as a higher oxygen reduction reaction (ORR) electrocatalytic activity, better operation stability, and higher tolerance to methanol than the commercial Pt/C catalyst in alkaline electrolyte.     

Fabrication of Fe‐Doped LiCoO2 Sandwich‐Like Nanocomposites as Excellent Performance Cathode Materials for Lithium‐Ion Batteries

In this article, the two‐layer sandwiched graphene@LiFe_0.2Co_0.8O₂ nanoparticles (SG@LFCO) have been prepared and investigated as high‐rate and long‐life cathode materials for rechargeable lithium‐ion batteries. The materials possess a high‐surface area (267.1 m² g^?1) and lots of void spaces. By combining various favorable conditions, such as Fe doping, coating graphene, and designing novel morphology, the as‐prepared materials deliver a specific capacity of 115 mAh g^?1 at 10 C. At the 0.1 C cycling rate, the capacity retention of 97.2 % is sustained after 250 cycles and a coulombic efficiency of around 97.6 % is obtained.     

Porous Nitrogen‐Doped Carbon Nanotubes Derived from Tubular Polypyrrole for Energy‐Storage Applications

Porous nitrogen‐doped carbon nanotubes (PNCNTs) with a high specific surface area (1765 m² g^?1) and a large pore volume (1.28 cm³ g^?1) have been synthesized from a tubular polypyrrole (T‐PPY). The inner diameter and wall thickness of the PNCNTs are about 55 nm and 22 nm, respectively. This material shows extremely promising properties for both supercapacitors and for encapsulating sulfur as a superior cathode material for high‐performance lithium–sulfur (Li‐S) batteries. At a current density of 0.5 A g^?1, PNCNT presents a high specific capacitance of 210 F g^?1, as well as excellent cycling stability at a current density of 2 A g^?1. When the S/PNCNT composite was tested as the cathode material for Li‐S batteries, the initial discharge capacity was 1341 mAh g^?1 at a current rate of 1 C and, even after 50 cycles at the same rate, the high reversible capacity was retained at 933 mAh g^?1. The promising electrochemical energy‐storage performance of the PNCNTs can be attributed to their excellent conductivity, large surface area, nitrogen doping, and unique pore‐size distribution.     

ZnO/Co3O4 Porous Nanocomposites Derived from MOFs: Room‐Temperature Ferromagnetism and High Catalytic Oxidation of CO

ZnO/Co₃O₄ porous nanocomposites were successfully fabricated by the thermal decomposition of Prussian Blue analogue (PBA) Zn₃[Co(CN)₆]₂ nanospheres obtained at room temperature. Interestingly, ZnO/Co₃O₄ porous nanocomposites exhibit room‐temperature ferromagnetism. Moreover, the ZnO/Co₃O₄ porous nanocomposites show good catalytic activity for CO oxidation, and the CO conversion rate reaches 100 % at 250 °C. It is suggested that the synergistic effect of each component, relative high surface area (32 m² g^?1) and porous structure lead to the promising catalytic properties.     

Highly Crystalline Mesoporous Phosphotungstic Acid: A High‐Performance Electrode Material for Energy‐Storage Applications

Heteropoly acids (HPAs) are unique materials with interesting properties, including high acidity and proton conductivity. However, their low specific surface area and high solubility in polar solvents make them unattractive for catalytic or energy applications. This obstacle can be overcome by creating nanoporosity within the HPA. We synthesized mesoporous phosphotungstic acid (mPTA) with a spherical morphology through the self‐assembly of phosphotungstic acid (PTA) with a polymeric surfactant as stabilized by KCl and hydrothermal treatment. The mPTA nanostructures had a surface area of 93 m² g^?1 and a pore size of 4 nm. Their high thermal stability (ca. 450 °C) and lack of solubility in ethylene carbonate/diethyl carbonate (EC/DEC) electrolyte are beneficial for lithium‐ion batteries (LIBs). Optimized mPTA showed a reversible capacity of 872 mAh g^?1 at 0.1 A g^?1 even after 100 cycles for LIBs, as attributed to a super‐reduced state of HPA and the storage of Li ions within the mesochannels of mPTA.     

High‐Rate Oxygen Electroreduction over Graphitic‐N Species Exposed on 3D Hierarchically Porous Nitrogen‐Doped Carbons

Nitrogen‐doped species (NDs) are theoretically accepted as a determinant of the catalytic activity of metal‐free N‐doped carbon (NC) catalysts for oxygen reduction reaction (ORR). However, direct relationships between ND type and ORR activity have been difficult to extract because the complexity of carbon matrix impairs efforts to expose specific NDs. Herein, we demonstrate the fabrication of a 3D hierarchically porous NC catalyst with micro‐, meso‐, and macroporosity in one structure, in which sufficient exposure and availability of inner‐pore catalytic sites can be achieved due to its super‐high surface area (2191 cm² g^?1) and interconnected pore system. More importantly, in‐situ formation of graphitic‐N species (GNs) on the surface of NC stimulated by KOH activation enables us to experimentally reveal the catalytic nature of GNs for ORR, which is of great significance for the design and development of advanced metal‐free NC electrocatalysts.     

Construction of CoO/Co‐Cu‐S Hierarchical Tubular Heterostructures for Hybrid Supercapacitors

Hierarchical hollow structures for electrode materials of supercapacitors could enlarge the surface area, accelerate the transport of ions and electrons, and accommodate volume expansion during cycling. Besides, construction of heterostructures would enhance the internal electric fields to regulate the electronic structures. All these features of hierarchical hollow heterostructures are beneficial for promoting the electrochemical properties and stability of electrode materials for high‐performance supercapacitors. Herein, CoO/Co‐Cu‐S hierarchical tubular heterostructures (HTHSs) composed of nanoneedles are prepared by an efficient multi‐step approach. The optimized sample exhibits a high specific capacity of 320 mAh g^?1 (2300 F g^?1) at 2.0 A g^?1 and outstanding cycling stability with 96.5 % of the initial capacity retained after 5000 cycles at 10 A g^?1. Moreover, an all‐solid‐state hybrid supercapacitor (HSC) constructed with the CoO/Co‐Cu‐S and actived carbon shows a stable and high energy density of 90.7 Wh kg^?1 at a power density of 800 W kg^?1.     

Functional Porous Carbon/Nickel Oxide Nanocomposites as Binder‐Free Electrodes for Supercapacitors

High‐surface‐area, guava‐leaf‐derived, heteroatom‐containing activated carbon (GHAC) materials were synthesized by means of a facile chemical activation method with KOH as activating agent and exploited as catalyst supports to disperse nickel oxide (NiO) nanocrystals (average size (2.0±0.1) nm) through a hydrothermal process. The textural and structural properties of these GHAC/NiO nanocomposites were characterized by various physicochemical techniques, namely, field‐emission SEM, high‐resolution TEM, elemental analysis, X‐ray diffraction, X‐ray photoelectron spectroscopy, thermogravimetric analysis, and Raman spectroscopy. The as‐synthesized GHAC/NiO nanocomposites were employed as binder‐free electrodes, which exhibited high specific capacitance (up to 461 F g^?1 at a current density of 2.3 A g^?1) and remarkable cycling stability, which may be attributed to the unique properties of GHAC and excellent electrochemical activity of the highly dispersed NiO nanocrystals.     

Three‐Dimensional Nitrogen‐Doped Hierarchical Porous Carbon as an Electrode for High‐Performance Supercapacitors

A facile and sustainable procedure for the synthesis of nitrogen‐doped hierarchical porous carbons with a three‐dimensional interconnected framework (NHPC‐3D) was developed. The strategy, based on a colloidal crystal‐templating method, utilizes nitrogenous dopamine as the precursor due to its unique properties, including self‐polymerization under mild alkaline conditions, coating onto various surfaces, a high carbonization yield, and well‐preserved nitrogen doping after heat treatment. The obtained NHPC‐3D possesses a high surface area of 1056 m² g^?1, a large pore volume of 2.56 cm³ g^?1, and a high nitrogen content of 8.2 wt %. The NHPC‐3D is implemented as the electrode material of a supercapacitor and exhibits a specific capacitance as high as 252 F g^?1 at a current density of 2 A g^?1. The device also shows a high capacitance retention of 75.7 % at a higher current density of 20 A g^?1 in aqueous electrolyte due to a sufficient surface area for charge accommodation, reversible pseudocapacitance, and minimized ion‐transport resistance, as a result of the advantageous interconnected hierarchical porous texture. These results showcase NHPC‐3D as a promising candidate for electrode materials in supercapacitors.     

Surface Plasmon Resonance‐Enhanced Visible‐NIR‐Driven Photocatalytic and Photothermal Catalytic Performance by Ag/Mesoporous Black TiO2 Nanotube Heterojunctions

Ag/mesoporous black TiO₂ nanotubes heterojunctions (Ag‐MBTHs) were fabricated through a surface hydrogenation, wet‐impregnation and photoreduction strategy. The as‐prepared Ag‐MBTHs possess a relatively high specific surface area of ≈85 m² g^?1 and an average pore size of ≈13.2 nm. The Ag‐MBTHs with a narrow band gap of ≈2.63 eV extend the photoresponse from UV to the visible‐light and near‐infrared (NIR) region. They exhibit excellent visible‐NIR‐driven photothermal catalytic and photocatalytic performance for complete conversion of nitro aromatic compounds (100 %) and mineralization of highly toxic phenol (100 %). The enhancement can be attributed to the mesoporous hollow structures increasing the light multi‐refraction, the Ti³⁺ in frameworks and the surface plasmon resonance (SPR) effect of plasmonic Ag nanoparticles favoring light‐harvesting and spatial separation of photogenerated electron–hole pairs, which is confirmed by transient fluorescence. The fabrication of this SPR‐enhanced visible‐NIR‐driven Ag‐MBTHs catalyst may provide new insights for designing other high‐performance heterojunctions as photocatalytic and photothermal catalytic nanomaterials.