Biomass Precursors Research Articles

Biomass nanoarchitectonics for porous carbon materials with exceptionally high mesoporous ratio through urea-regulated co-activation strategy and their application in supercapacitors

The synthesis of porous carbon with a high mesoporous ratio is a significant challenge, particularly when utilizing heteroatom-enriched biomass precursors as feedstock. In this work, bio-based porous carbon with a 95 % mesoporous ratio was synthesized by using chitosan and lignosulfonates as biomass precursors, combined with a urea-regulated co-activation strategy. The high mesoporous formation of porous carbon can primarily be attributed to four factors: (1) the formation of a cross-linked 3D network, (2) the generation of nitrogen-containing gas resulting from urea decomposition, (3) the depolymerization of LS and (4) KOH-activated carbonization. Besides, the specific surface area and mesoporous ratio can be adjusted by varying the ratio of KOH to urea, ranging from 1793 m2 g−1 to 2876 m2 g−1 and from 22 % to 95 %, respectively. The application of density functional theory calculations reveals that the synergistic effect of N/S co-doping facilitates rapid ion adsorption reactions on carbon surfaces, further improving the electrochemical performance. As carbon electrode materials for supercapacitors in a three-electrode device, the capacitance reaches up to 263 F g−1 at 1 A g−1. The symmetric supercapacitors fabricated using CS@LS/C-800–1:0.5 achieved an impressive energy density of 17.8 Wh·kg−1 at a power density of 300.6 W kg−1, along with a remarkable capacitance retention rate of 96.6 %. This strategy provides a novel insight into enhancing the mesoporous ratio of bio-based porous carbon materials, thereby significantly broadening the application scope of biomass materials.

Electrocatalytic activities of iron-supported N-doped porous carbon towards the oxygen/hydrogen evolution reaction

Red mud (RM) disposal has been highly apprehensive due to its environmental impact. The aluminum industry produces large amounts of red mud waste annually, and turning it into a value-added product is a key component of sustainable development. This study combines RM with an N-doped porous carbon (biomass precursor) as an effective electrocatalyst for oxygen evolution and hydrogen evolution reactions (OER and HER). One significant obstacle to anion-exchange membrane (AEM) electrolyzer applications is the development of electrocatalysts that do not require noble metals and are both efficient and effective at HER and OER. The synthesized iron-supported (RM-derived) N-doped porous carbon (RMNPC) exhibits excellent catalytic activities with 276 and 191 mV overpotentials at 10 mA cm−2 for OER and HER, respectively. A two-electrode cell system is designed with an RMNPC/NF electrode as anode and cathode, and it necessitates just 1.82 V to realize 10 mA cm−2 and shows outstanding durability. This study presents a low-cost but effective electrocatalyst for water splitting for renewable hydrogen production, achieving the goal of RM recycling and highlighting the potential of porous carbon electrocatalysts.

Enhanced storage performance of a low-cost hard carbon derived from biomass

Hard Carbon is the most widely used negative electrode material for sodium-ion batteries today. Achieving high storage capacity and increasing the plateau capacity, as opposed to the sloping profile, are crucial for enhancing energy density of the full cells. While several publications address the synthesis of hard carbon, the economic viability for commercial scale-up hinges on the choice of precursors. In this study, we report the electrochemical properties of hard carbon derived from two biomass precursors, sugarcane waste (bagasse) and corn waste, and compare their performances with commercially available hard carbon. The hard carbon derived from bagasse delivers a capacity of 307 mAh/g at C/10 rate and retains approximately 234 mAh/g at 3C discharge rate. We integrate surface area, pore size distribution, Raman spectroscopy, small-angle X-ray and neutron scattering data to elucidate the sodium storage mechanism in these hard carbon samples. Correlated graphitic domains with hexagonal ordering along with fractal like agglomeration of the nanosheets are quantified. The high plateau capacity of the bagasse-derived hard carbon is attributed to the characteristic morphology and size distribution of the nanosheets and their nature of agglomeration.

Solar‐Driven Reforming of Lignocellulosic Biomass to Renewable Biohydrogen: A Review

AbstractTo date, humans are looking for suitable energy sources to meet the global demand for fuels. Among many candidates, biohydrogen (bio‐H2), a future fuel perspective, is expected to grow critically and receive considerable attention to replace fossil fuels. This review focuses on biohydrogen production via post‐method photocatalytic reforming of ideal feedstock and abundant lignocellulosic biomass. Renewable biomass precursors are used without net greenhouse gas emissions. This idea holds great promise as a sustainable and environmentally friendly energy solution. In particular, many saccharide substrates, including monosaccharides, disaccharides, polysaccharides, etc., have been used as sacrificial reagents in photocatalytic reforming over the past few decades. Among the various substrates, cellulose has attracted worldwide attention since it is the most abundant polymeric biomass resource that can be obtained from many sources. Following, photo‐reforming of renewable lignocellulosic biomass, which aligns with the requirements of sustainable development, is successfully proposed. The overall catalytic efficiency will be discussed regarding the biohydrogen evolution rate (mmol gcat−1 h−1). Finally, the review concluded with challenges and potential opportunities to enhance biohydrogen are also given.

Manganese Oxide-Doped Hierarchical Porous Carbon Derived from Tea Leaf Waste for High-Performance Supercapacitors.

Hierarchical porous carbon derived from discarded biomass for energy storage materials has attracted increasing research attention due to its cost-effectiveness, ease of fabrication, environmental protection, and sustainability. Brewed tea leaves are rich in heteroatoms that are beneficial to capacitive energy storage behavior. Therefore, we synthesized high electrochemical performance carbon-based composites from Tie guan yin tea leaf waste using a facile procedure comprising hydrothermal, chemical activation, and calcination processes. In particular, potassium permanganate (KMnO4) was incorporated into the potassium hydroxide (KOH) activation agent; therefore, during the activation process, KOH continued to erode the biomass precursor, producing abundant pores, and KMnO4 synchronously underwent a redox reaction to form MnO nanoparticles and anchor on the porous carbon through chemical bonding. MnO nanoparticles provided additional pseudocapacitive charge storage capabilities through redox reactions. The results show that the amount of MnO produced is proportional to the amount of KMnO4 incorporated. However, the specific surface area of the composite material decreases with the incorporated amount of KMnO4 due to the accumulation and aggregation of MnO nanoparticles, thereby even blocking some micropores. Optimization of MnO nanocrystal loading can promote the crystallinity and graphitization degree of carbonaceous materials. The specimen prepared with a weight ratio of KMnO4 to hydrochar of 0.02 exhibited a high capacitance of 337 F/g, an increase of 70%, owing to the synergistic effect between the Tie guan yin tea leaf-derived activated carbon and MnO nanoparticles. With this facile preparation method and the resulting high electrochemical performance, the development of manganese oxide/carbon composites derived from tea leaf biomass is expected to become a promising candidate as an energy storage material for supercapacitors.

Exploring the Mechanisms and Kinetic Modeling of Phenol Amination Using Pd and Rh‐Based Catalysts

AbstractProducing biomass‐derived chemicals to substitute their petrochemical counterparts has long been an aspiration of the green chemistry research community. However, synthesizing secondary amines from biomass precursors presents several challenges related to catalyst nature and the mechanistic understanding of reaction systems. Here, we unravel the mechanistic and kinetic implications of the reductive amination of phenol with cyclohexylamine over Pd/C and Rh/C. A competitive Langmuir‐Hinshelwood reaction model well interpreted the kinetic data, suggesting that support‐metal interfaces serve as active sites for H2, ─NH2 and ═NH activation. The apparent activation energies for imine hydrogenation were 87.6 kJ mol−1 (Pd/C) and 34.5 kJ mol−1 (Rh/C), while ΔHads and ΔSads values confirmed the physicochemical consistency of the model. Moreover, the catalysts demonstrated their high stability to operate for several catalytic cycles, with minor activity losses due to metal leaching and partial sintering of Pd nanoparticles. Despite phenol reductive amination following similar mechanisms on Rh/C and Pd/C, they show differences in selectivity because the hydrogenation of imine is more efficient on Rh0 than on Pd0. This is the first mechanism‐oriented kinetic study for phenol reductive amination; thus, it provides valuable information for process design and scale‐up.

Roles of network topology in the relaxation dynamics of simple chemical reaction network models

Understanding the relationship between the structure of chemical reaction networks and their reaction dynamics is essential for unveiling the design principles of living organisms. However, while some network-structural features are known to relate to the steady-state characteristics of chemical reaction networks, mathematical frameworks describing the links between out-of-steady-state dynamics and network structure are still underdeveloped. Here, we characterize the out-of-steady-state behavior of a class of artificial chemical reaction networks consisting of the ligation and splitting reactions of polymers. Within this class, we examine minimal networks that can convert a given set of sources (e.g., nutrients) to a specified set of targets (e.g., biomass precursors). By exploring the dynamics of the models with a simple setup, we find three distinct types of relaxation dynamics after perturbation from a steady-state: exponential-, power-law-, and plateau-dominated. We computationally show that we can predict this out-of-steady-state dynamical behavior from just three features computed from the network’s stoichiometric matrix, namely, (1) the rank gap, determining the existence of a steady-state; (2) the left null-space, being related to conserved quantities in the dynamics; and (3) the stoichiometric cone, dictating the range of achievable chemical concentrations. We further demonstrate that these three quantities relates to the type of relaxation dynamics of combinations of our minimal networks, larger networks with many redundant pathways, and a real example of a metabolic network. The relationship between the topological features of reaction networks and the relaxation dynamics presented here are useful clues for understanding the design of metabolic reaction networks as well as industrially useful chemical production pathways.

Defect-rich hard carbon designed by heteroatom escape assists sodium storage performance for sodium-ion batteries

Sodium-ion batteries (SIBs) avoids the use of expensive cobalt element, and the abundance of sodium element is high, so it shows great application potential, and the development of sodium-ion battery materials is of great value. Biomass precursors have the advantages of low cost and widely and sufficiently distributed resources, and embody the environmental concept of waste utilization, however, the poor reversible specific capacity and initial coulombic efficiency (ICE) of pristine corn stover-derived hard carbons (CSHCs) limit their practical application value. In this paper, we propose a method to increase the reversible specific capacity of hard carbon and maintain high ICE, introduce heteroatoms into graphene-like nanosheets at low carbonization temperature, then escape heteroatoms through high pyrolysis temperature, create defects in the graphene-like carbon layer and expand the (002) layer spacing. Density functional theory (DFT) calculations show that defects are beneficial to the adsorption of Na+ on graphene-like nanosheets, and Na+ have a lower diffusion barrier between layers rich in defects and extended (002) layer spacing. Compared with the conventional low pyrolysis temperature heteroatom doping process, the present method exhibits superior ICE. In the ester-based electrolyte, the modified hard carbon (D-CSHC) exhibits a superior specific capacity of 284.5 mAh/g and an ICE of 85.9 % as compared to the pristine corn stover-derived hard carbon (233.5 mAh/g, 72.7 %). In addition, the capacity retention rate was 92.6 % after 500 turns of constant current cycles at 0.15 A/g.

Biomass-Derived Cellulose Acetate Membranes Modified with TiO2/Graphene Oxide for Oil-In-Water Emulsion Treatment.

Considering the environmental impact and health risks caused by oily wastewater in the petrochemical industry, it is crucial to develop more efficient separation techniques than traditional methods, such as membrane separation, for treating stable emulsions enriched with natural surfactants. This study investigated the preparation of dense cellulose acetate membranes from a low-cost biomass precursor (Luffa cylindrica) and their modification with graphene oxide (GO) and TiO2 nanoparticles, aiming to obtain a polymeric nanocomposite with good flux characteristics and selectivity for the treatment of oil/water emulsions. The materials obtained were characterized using techniques such as X-ray diffraction, nuclear magnetic resonance spectroscopy, infrared absorption spectroscopy, along with optical and scanning electron microscopy, among others. The membranes were prepared by the casting technique and modified with the above-mentioned nanostructured materials. Flux analyses with petroleum emulsion revealed that membranes modified with GO and TiO2 nanoparticles showed significant improvements in antifouling resistance compared to unmodified membranes. These enhanced properties highlight the potential of modified cellulose acetate membranes for application in industrial wastewater treatment.

Ni and Co-based bifunctional electrocatalysts supported on TiO2@C for oxygen evolution and reduction reactions

In the search for affordable, ecofriendly, and sustainable catalysts for energy-related processes, series of Ni and Co-based bifunctional hybrid electrocatalysts supported on TiO2@C were prepared and studied in the oxygen evolution (OER) and oxygen reduction reactions (ORR). The hybrid TiO2@C supports were prepared using three biomass precursors: furfural, chitosan and saccharose. The nature and dispersion of the metallic phases on those supports was evaluated as a function of the biomass-derived precursors. The prepared materials showed electrocatalytic activity towards ORR and OER reaction, being more active for the latter. Despite a lower performance than Pt/C benchmark, these materials are clearly at much lower costs. The long-term stability and performance of the catalysts were also performed. The number of electrons involved in both processes was determined and a mechanism is proposed for the understanding of the mechanism of reactions using the present materials. It can be concluded that the Ni and mainly Co-based electrocatalysts show a remarkable potential for use as alternative catalysts in fuel cells-related reactions.

Regulating the Pore Structure of Biomass-Derived Hard Carbon for an Advanced Sodium-Ion Battery.

Biomass-derived hard carbon materials are attractive for sodium-ion batteries due to their abundance, sustainability, and cost-effectiveness. However, their widespread use is hindered by their limited specific capacity. Herein, a type of bamboo-derived hard carbon with adjustable pore structures is developed by employing a ball milling technique to modify the carbon chain length in the precursor. It is observed that the length of the carbon chain in the precursor can effectively control the rearrangement behavior of the carbon layers during the high-temperature carbonization process, resulting in diverse pore structures ranging from closed pores to open pores, which significantly impact the electrochemical properties. The optimized hard carbon with abundant closed pores exhibits a high specific capacity of 356 mAh g-1 at 20 mA g-1, surpassing that of bare hard carbon (243 mAh g-1) and hard carbon with abundant open pores (129 mAh g-1 at 20 mA g-1). However, the kinetic analysis reveals that hard carbon with open pores shows better sodium-ion diffusion kinetics, indicating that a balance between the closed and open pores should be considered. This research offers valuable insights into pore design and presents a promising approach for enhancing the performance of hard carbon anode materials derived from biomass precursors.

Recent Advances in Biomass‐Derived Carbon‐Based Nanostructures for Electrocatalytic Reduction Reactions: Properties–Performance Correlations

Developing affordable and high‐performance catalysts for water electrolyzers and fuel cell devices is an emerging field of research aiming for their feasible implementation and thus addressing sustainable global energy demands. Accordingly, several catalytic systems have been developed for anodic oxidation reactions and cathodic reduction reactions. Specifically, more research attention has been focused on viable catalyst synthesis processes including design, choice of precursors, reaction conditions, and regulation steps for achieving desirable properties and performances. Intriguingly, biomass has been demonstrated as a promising precursor for the potential design of different carbon‐based catalysts for electrocatalytic oxidation/reduction reactions. In this review, the recent developments in using biomass precursors to derive different nanostructures are systematically discussed. The biomass‐derived catalysts especially applied for reduction reactions (hydrogen evolution and oxygen reduction reactions) are summarized, and the impact of various catalysts’ engineering routes (incorporation of metals and nonmetals into the carbon structures) on the resulting structure–performance relationship is critically discussed. Further, this review highlights the performance of various biomass‐derived catalysts toward electrocatalytic reduction reactions that unveil the catalyst's intrinsic features such as selectivity, activity, and durability. The summarized results and the critical discussion will facilitate screening of the best biomass precursor, identifying suitable regulation strategies for accomplishing desirable properties, and thus advancing the next‐generation catalysts’ developments. Further, the significance, challenges, and perspectives on biomass‐derived catalysts for electrocatalysis are comprehensively discussed.

From Natural Fibers to High-Performance Anodes: Sisal Hemp Derived Hard Carbon for Na-/K-Ion Batteries and Mechanism Exploration.

Hard carbon (HC) is a promising anode material in alkali metal ion batteries owing to its cost-effectiveness, abundant sources, and low working voltage. However, challenges persist in achiving prolonged cycling stability and consistent capacity, and the sodium storage mechanism in HC is still debated. Herein, an unreported biomass precursor, "sisal," for deriving hard carbon is developed. A series of sisal hemp-derived hard carbon with natural 3D porous channels are prepared. Through phase characterization and electrochemical testing, the relationship between microstructure and sodium storage capacity is elucidated, further confirming the suitability of the "adsorption-insertion-filling" mechanism for sodium storage properties in hard carbon materials. Without the need for any additional modification strategies, this biomass-derived hard carbon demonstrates excellent electrochemical performance in both sodium-ion and potassium-ion batteries (SIBs and PIBs). The as-prepared HC-1300 demonstrates excellent ion storage capability, delivering a high reversible capacity of 345.2mAhg-1 in SIBs and 310mAhg-1 in PIBs at 0.1C. Moreover, it maintains a specific capacity of 237.3mAhg-1 over 1200 cycles at 1C when used in SIBs. The excellent cycling stability and superior rate performance are also presented in full cells, highlighting its potential for practical applications.

Performance study of high energy storage supercapacitor from waste corn husk biomass electrode materials

Waste biomass carbon materials are used as green and environmentally friendly electrode materials for supercapacitors (SCs) have great development prospects, therefore, miscellaneous elements-rich and recycled renewable porous carbon materials have important applications value in the field of energy storage device. In this paper, waste corn husk as biomass precursor to prepare corn husk porous carbon (CHPC) using two steps of high-temperature carbonization and KOH activation. The CHPC-2 optimized by KOH shows a specific surface area (SSA) of 1103 m2 g−1 and a total pore volume of 0.83 cm3 g−1, achieving a high specific capacitance of 413.4 F g−1 at 0.5 A g−1. After 10,000 cycles, only 4.17 % of the capacitance was lost. In a two-electrode system with 1 M Na2SO4 as the electrolyte, CHPC-2//CHPC-2 exhibits a specific capacitance of 333 F g−1 at a wide voltage window of 0–1.8 V, and energy density of 37.46 Wh Kg−1 when power density is 450 W kg−1, which possesses the capacitance retention rate of 85.16 % after 5000 cycles. The assembled symmetrical SCs contain capacitance of 308.79 F g−1, and 21.02 Wh kg−1 under a power density of 350 W kg−1 in PVA/KOH gel electrolyte. Consequently, CHPC materials provide a scientific and reasonable research idea for the development of SCs with inexpensive, non-polluting, and high energy density.

Green synthesis of soybean residue-based nitrogen-chlorine co-doped carbon dots based on deep eutectic solvents: Construction of a PNP fluorescence detection system under the IFE mechanism

How to manage the potential environmental pollution of waste biomass while realizing the resource utilization of the waste is a topic worthy of in-depth investigation. In this paper, after successfully preparing a deep eutectic solvents, we constructed N, Cl-CDs fluorescent probes with high fluorescence yield and biocompatibility by utilizing waste soybean residue as a cheap nitrogen-rich carbon-sourced biomass precursor. The results showed that the fluorescence quenching of N, Cl-CDs has a good linear relationship with the concentration of p-nitrophenol in the range of 0.1–60 μM, with the detection limit of 30 nM, and the fluorescence quenching mechanism was the inner filter effect. This paper demonstrates that the carbon dots fluorescence system has a superior prospect for the highly selective detection of p-nitrophenol, and provides a reliable basis for the future exploration of efficient and environmentally friendly carbon dots synthetic method as well as the economic recycling of waste.

Simultaneous voltammetric detection of acetaminophen and levofloxacin based on barley leaves derived carbon decorated with gold nanoparticles

In this study, barley leaves were used as biomass precursor to prepare the ZnCl2 activated barley leaves derived carbon by the carbonization under N2 atmosphere at high temperature (ZnAC). The gold nanoparticles were synthesized in situ on the surface of ZnAC (AuNPs/ZnAC). The as-prepared AuNPs/ZnAC composite was characterized by SEM, Raman spectroscopy, XRD et. al. The AuNPs/ZnAC composite was drop-cast onto the surface of a glassy carbon electrode to fabricate an electrochemical sensing platform for the simultaneous determination of acetaminophen (AC) and levofloxacin (LEV). The results of electrochemical experiments showed that ZnAC and AuNPs had a synergetic electrocatalytic effect on the oxidation of AC and LEV. The oxidation peak potentials of AC and LEV were at 0.57 and 1.02 V, respectively. The proposed sensor allowed the simultaneous quantification of AC and LEV two linear intervals: in the ranges of 0.1–15 and 15–300 μM for AC and 0.1–20 and 20–300 μM for LEV with the detection limits of 0.02 and 0.03 μM, respectively. In addition, the sensor has the advantages of low cost, high sensitivity, simple preparation and environmental friendliness, as well as good selectivity, stability and reproducibility. We measured AC and LEV in artificial urine, tap water, and lake water, and the recoveries were between 93 % and 109 %, indicating that the sensor has good application prospects in biomedicine and environmental protection.

Pennisteum glaucum-derived carbon dots, synthesized through green approach to degrade Rose Bengal and Methylene Blue dyes photocatalytically

In the present study, carbon dots (C-dots) were synthesized using a simple and uncomplicated pyrolysis method at 250 °C with varying duration of 1 h, 2 h, and 3 h, utilizing Pennisetum glaucum as the biomass precursor to break down methylene blue (MB) and Rose Bengal (RB) dyes under UV light exposure. Various analytical techniques, including X-ray diffraction (XRD), UV–visible spectroscopy, high-resolution transmission electron microscopy (HR-TEM), Fourier-transform infrared spectroscopy (FT-IR), and vibrating-sample magnetometer (VSM), were utilized to investigate the chemical, optical, electronic, surface morphological, and magnetic characteristics of the C-dots produced. These C-dots are crystalline, nearly spherical, and have particle sizes ranging from 4.73 nm to 12.44 nm. FTIR analysis identified the functional groups present on the surface of the C-dots. Additionally, the band gap energy of the C-dots reduced from 2.82 eV to 2.40 eV with an increase in pyrolysis time. They are effective for cleaning dye-polluted wastewater and demonstrate high photocatalytic performance. When exposed to UV light, the synthesized particles achieved impressive photocatalytic degradation of 94.80 % for MB and 91.80 % for RB dyes.

Sustainable synthesis of fluorescent polymercarbon dots@PVA for sensitive chlortetracycline detection.

Antibiotic residues persist in the environment and represent serious health hazards; thus, it is important to develop sensitive and effective detection techniques. This paper presents a bio-inspired way to make water-soluble fluorescent polymer carbon dots (PCDs@PVA) by heating biomass precursors and polyvinyl alcohol (PVA) together. For example, the synthesized PCDs@PVA are very stable with enhanced emission intensity. This property was observed in a wide range of environmental conditions, including those with changing temperatures, pH levels, UV light, and ionic strength. PCDs@PVA detected the antibiotic chlortetracycline (CTCs) with great selectivity against structurally related compounds and a low detection limit of 20 nM, demonstrating outstanding sensitivity and specificity. We confirmed the sensor's practical application through real sample analysis, yielding recovery rates of 98%-99% in samples of milk, honey, and river water. The synthesized PCDs@PVA fluorescence sensor was successfully used for CTCs detection in real samples.

Renewable Musa Sapientum derived porous nano spheres for efficient energy storage devices

Biomass-based carbonaceous materials derived from Musa Sapientum have gained much attention in recent years for their application in energy storage devices, especially supercapacitors. In the present work, we synthesized carbonaceous material from banana peel as the biomass precursor by using a pyrolysis method carried out at various temperatures (600, 800, and 1000 °C). The characterization of the prepared carbonaceous materials BP600, BP800 and BP1000 was done by using different characterization techniques such as FTIR, XRD, FE-SEM, and TEM, studies. The electrochemical study of the synthesized material was carried out by cyclic voltammetry (CV), galvanostatic charge–discharge (GCD) electrochemical impedance spectroscopy (EIS). The supercapacitive performance of the material was studied using a 3-electrode system with 3M KOH as an electrolyte. As a result, the BP600 exhibited a better specific capacitance with higher energy and power densities along with a maximum cyclic stability of 16,000 cycles. To show the practical applicability of the material BP 600, two electrode system studies were carried out as well, which showed preferentially good values for specific capacitance with appreciable power and energy density values. The study provides us with a green approach for the fabrication of non-toxic, low-cost, and environmentally friendly potential porous carbonaceous electrode materials by converting bio-waste into a clean and renewable source of energy.

The synthesis of hollow carbon nanospheres from potato starch and the application in supercapacitor

The synthesis of high-valued carbon nanomaterials from biomass has always been a hot topic. The work reports the preparation of hollow carbon nanospheres (HCNs) from potato starch with one-step carbonization, in which self-made MgO powder is utilized as the template. In this study, an attempt was made to change carbonization temperature to control HCNs in diameter, wall thickness and pore distribution. Results show that the sample obtained at 800 °C (HCN-800) has a thinner wall thickness (about 12.1 nm), smaller and more uniform diameter (average diameter of 46.2 nm), as well as possesses a high specific surface area (619.53 m2 g−1) and the largest pore volume (2.8994 cm3 g−1). An application in supercapacitor has been verified for the HCNs in the work. In the three-electrode system, the HCN-800 exhibits excellent electrochemical performance, such as superior specific capacitance (324.8 F g−1 at 0.5 A g−1), high rate performance (215.7 F g−1 at 50 A g−1) and outstanding cycling stability (92.83 % capacitance retention after 10,000 cycles). Moreover, an assembled symmetric supercapacitor shows an energy density of 11.1 Wh kg−1 at a power density of 427 W kg−1, far exceeding that of previously reported carbon electrode materials. In short, the work provides a novel way to synthesize high-value-added HCNs from cheap biomass precursors, which have potential applications in the field of supercapacitors and other energy storage devices.