Low-cost Porous Carbon Research Articles

Fabrication of Low-Cost Porous Carbon Polypropylene Composite Sheets with High Photothermal Conversion Performance for Solar Steam Generation.

The development of absorber materials with strong light absorption properties and low-cost fabrication processes is highly significant for the application of photothermal conversion technology. In this work, a mixed powder consisting of NaCl, polypropylene (PP), and scale-like carbon flakes was ultrasonically pressed into sheets, and the NaCl was then removed by salt dissolution to obtain porous carbon polypropylene composite sheets (P-CPCS). This process is simple, green, and suitable for the low-cost, large-area fabrication of P-CPCS. P-CPCS has a well-distributed porous structure containing internal and external connected water paths. Under the dual effects of the carbon flakes and porous structure, P-CPCS shows excellent photothermal conversion performance in a broad wavelength range. P-CPCS-40 achieves a high temperature of 128 °C and a rapid heating rate of 12.4 °C/s under laser irradiation (808 nm wavelength, 1.2 W/cm2 power). When utilized for solar steam generation under 1 sun irradiation, P-CPCS-40 achieves 98.2% evaporation efficiency and a 1.81 kg m-2 h-1 evaporation rate. This performance means that P-CPCS-40 outperforms most other previously reported absorbers in terms of evaporation efficiency. The combination of carbon flakes, which provide a photothermal effect, and a porous polymer structure, which provides light-capturing properties, opens up a new strategy for desalination, sewage treatment, and other related fields.

In-situ electropolymerized polyaniline nanoparticles grown on longan shell-derived porous carbon for high-performance supercapacitor electrode

In this study, novel in-situ electropolymerized polyaniline nanoparticles grown on longan shell-derived porous carbon were prepared for high-performance supercapacitor electrode, which exhibited a high specific capacitance of 486F·g−1 at the current density of 0.5 A·g−1 in 1 M H2SO4 electrolyte via a three-electrode test. Further, the asymmetric supercapacitor was constructed with the energy density as high as 47.3 Wh·kg−1 at the power density of 800 W·kg−1 and excellent durability, in which the retention rate of specific capacitance was still as high as 85 % over 10,000 cycles. The excellent electrochemical performance of the as-prepared composite electrode material can be attributed to the large specific surface area of longan shell-derived porous carbon with honeycomb-like morphology up to 1613.2 m2·g−1, as well as the homogeneous electropolymerization of polyaniline nanoparticles grown on porous carbon, resulting in efficient pseudocapacitive charge storage. Noteworthily, natural longan shell as a renewable carbon source can be suitable for the preparation of high-quality and low-cost porous carbon to significantly improve the performance of supercapacitor electrode, which also provides a feasible pathway for high-value utilization of waste biomass resources.

A green potassium citrate activation strategy via one-step synthesis of 3D porous carbon for capacitive deionization

Capacitive deionization (CDI) shows potential for desalination whereas exploring green and low-cost porous carbon electrodes exhibiting good desalination performance is still challenging. Herein, a green one-step carbonization-activation strategy was developed with carboxymethyl cellulose (CMC) as precursor and potassium citrate as activator to prepare CA(K)/CMC for CDI desalination. Owing to the introduction of potassium citrate, CA(K)/CMC exhibited larger specific surface area, better porous structure, more defects, and richer oxygen content. These improvements effectively accelerated charge transfer and ion transport process in CA(K)/CMC, which significantly increased the specific capacitance of CA(K)/CMC. Owing to the synergistic effect of these above properties, the optimized CA(K)/CMC-1-2 demonstrated high salt adsorption capacity (17.21 mg g−1, 1.2 V, 200 mg/L) and desalination rate (0.023 mg g−1 s−1, 1.2 V, 200 mg/L), and good cycling stability. Density functional theory (DFT) calculations further verified the advantageous characteristics of CA(K)/CMC-1-2 indeed improved ions adsorption. This finding offers new insights for designing green and economical carbon-based electrodes for desalination by CDI.

Novel hydrophobic hierarchical porous carbon from sewage sludge for the efficient capture of gaseous iodine

Finding an inexpensive and efficient porous adsorbent to capture the gaseous radioiodine generated during spent fuel reprocessing has been challenging. Herein, we present a design philosophy for waste control to develop porous carbon for gaseous iodine capture from sewage sludge waste. Among them, the novel in situ etching of polytetrafluoroethylene was employed to improve pore accessibility. The hazards of the conventional preparation of sludge-derived carbon using highly corrosive NaOH and HF solutions were overcome. Polytetrafluoroethylene etched porous carbon with large specific surface area (1103 m2/g), interconnected hierarchical porous structure, and excellent hydrophobicity (water contact angle 126.52°), providing efficient adsorption of gaseous iodine in hot (30–150 °C) and humid (50–96% relative humidity [RH]) environments. The iodine adsorption of hierarchical porous carbon was tested under static and dynamic conditions, and high records have been achieved. Notably, due to the structural advantage of hydrophobicity, a considerable dynamic adsorption capacity (1746.77 mg/g) was also maintained in a mixed iodine gas stream containing water vapor in a humid (50% RH) hot (75 °C) condition. This study is the first to use an in situ etching strategy for polytetrafluoroethylene, which opens a new avenue for converting sludge waste into low-cost porous carbon and provides an attractive option for capturing iodine in hot and humid environments.

Hybrid electrolyte with biomass-derived carbon host for high-performance aqueous Zn–S battery

The aqueous Zinc-Sulfur battery (AZSB) utilizes earth-abundant zinc anode along with sulfur cathode, making it a low-cost and safe alternative with decent energy density. In order to tackle the side reactions at the cathode and anode, a hybrid electrolyte is developed by incorporating dimethyl carbonate (DMC) as a co-solvent and iodine as an additive. Incorporating an optimal amount of dimethyl carbonate (DMC) in the aqueous electrolyte does not compromise the conductivity and non-flammability of the AZSB system, yet brings effective changes to the solvation shell of the zinc ions, reducing the free water activity and thus, limiting the water-based side reactions. In addition, the hybrid electrolyte is found to improve the wettability of the sulfur cathode which enhances the reaction kinetics at the cathode. To support the hybrid electrolyte, a low-cost porous carbon material derived from waste jackfruit peel biomass is employed as the sulfur host on the cathode. Combining hybrid electrolyte and biomass-derived porous carbon–sulfur composite allows for an exceptional performance in AZSB, i.e., a capacity of 1167 mAh gS−1 at 0.1 A gS−1, along with an energy density of 502 Wh kgS−1. Even at a high rate of 1 A gS−1, the battery is able to retain 47.6 % capacity after 200 cycles. This innovative electrolyte design, coupled with the incorporation of an inexpensive porous carbon host, significantly enhances the Zn/S electrochemistry, showcasing the immense potential of AZSB for future applications.

Optimization of process variables to prepare activated carbon from Noug (Guizotia abyssinica cass.) stalk using response surface methodology

Even though adsorption is considered the simple, effective, and efficient method for the treatment of wastewater, accessibility of low-cost and locally available activated carbon remains the challenge. In response to this, recently significant amounts of agricultural byproducts have been investigated to prepare low-cost porous carbon, but there is still a problem related to cost and availability. So, Noug stalk, chosen because of its abundance and low cost as an agricultural byproduct in Ethiopia, was chemically activated with phosphoric acid to produce a low-cost porous carbon. The production of Noug stalk activated carbon (NSAC) is optimized using response surface methodology. A central composite design was used to investigate the effect of three process parameters, namely carbonization temperature (450–650 °C), activation time (90–150 min), and impregnation ratio (w/w) (1–3), on the BET surface area and yield of porous carbon. The analysis of variance (ANOVA) result shows that all three process parameters showed a significant effect on the surface area of porous carbon, while only carbonization temperature showed a significant effect on the yield of porous carbon. The best conditions for NSAC preparation were a carbonization temperature of 537.50 °C, an activation time of 127 min, and an impregnation ratio of 1.95, resulting in a BET surface area and yield of 473.45 m2 g−1 and 53.78%, respectively. The expected and observed values of the model for the outcome variable were highly comparable. Several analytical techniques, including proximal analysis, Fourier transform infrared spectroscopy, and N2 adsorption-desorption, were used to characterize the NSAC. The results demonstrated that the prepared NSAC has a highly porous structure comparable to porous carbon obtained from other biomass feedstocks. This implies it would be used as a potential low-cost alternative for wastewater treatment using the adsorption process.

High-value utilization of lignin to prepare N,O-codoped porous carbon as a high-performance adsorbent for carbon dioxide capture

The concern for environmental sustainability has increased the interest in biomass materials for the synthesis of porous carbon, especially as an effective alternative and multifunctional adsorbent in the field of adsorption of a wide range of pollutants and carbon dioxide. Lignin has high carbon content, abundant aromatic rings and condensation bonds, which make it suitable as a precursor for carbon-containing materials. In this study, lignin was firstly precarbonized to achieve its degradation and efficient conversion, and then chemically activated by KOH to prepare a low-cost porous carbon materials with finely developed microporous structure, which showed excellent gas adsorption performance of 3.98 and 5.82 mmol/g at 1 bar, 298 K and 273 K, respectively. In addition to this, we have also investigated the dynamic sorption properties of the samples on CO2. The original lignin contains N,O functional groups that can be doped to the surface of the porous carbon, and previous studies have confirmed that the porosity and functional groups on the surface of the carbon material play a positive role in improving the defective and adsorption properties of the material. Our work provided a promising strategy for valorization of lignin as a precursor for producing advanced carbon materials.

Agar-derived nitrogen-doped porous carbon as anode for construction of cost-effective lithium-ion batteries

Balancing cost and performance of porous carbon (PC) as anode for lithium-ion battery (LIBs) is the key to effectively promote commercial application. Herein, low-cost N-doped PC (NPC-Ts, T = 600, 750 and 900 °C) were facilely prepared in batches via one-pot pyrolysis of agar with different carbonization temperature. The NPC-750 with specific surface area of 2914 m2/g and N content of 2.84% exhibits an ultrahigh reversible capacity of 1019 mAh/g at 0.1 A/g after 100 cycles and 837 mAh/g at 1 A/g after 500 cycles. Remarkably, the resulting LIBs exhibit an ultrafast charge-discharge feature with a remarkable capacity of 281 mAh/g at 10 A/g and a superlong cycle life with a capacity retention of 87% after 5000 cycles at 10 A/g. Coupling with LiFePO4 cathode, the fabricated lithium-ion full cells possess high capacity, excellent rate and cycling performances (125 mAh/g at 100 mA/g, capacity retention of 95%, after 220 cycles), highlighting the practicability of this NPC-750 as the anode materials.

Ultra-stable sodium ion storage of biomass porous carbon derived from sugarcane

Development of low-cost anode for sodium-ion battery (NIB) has become the most desirable target in today’s energy demanding society. In this work, we present different treatments of sugarcane biomass to alter the lignocellulose compositions to obtain low-cost porous carbon as NIB’s anode. The optimized sugarcane biomass derived carbon presents the initial reversible capacity of 229 mAh g−1 and the reversible capacity of 189 mAh g−1 at 100 mA g−1 after 50 cycles. It is worth noting that the carbon also exhibits an extremely low voltage plateau with 74.2 % of discharge capacity originating from the voltages below 0.5 V. In addition, the sugarcane biomass derived carbon displays an ultra-stable capacity with almost no attenuation even after 2000 cycles. In consideration of the low voltage plateau, we also calculated the relative energy density (ER, combination of the capacity and voltage plateau), and a high ER of 500 Wh kg−1 in the first cycle and 416 Wh kg−1 after 50 cycles are obtained. In situ TEM analysis was conducted to investigate the structural stability of sugarcane biomass derived carbon. Small volumetric changes are observed at different charge-discharge states, indicating the structural stability of our sugarcane biomass derived carbon during sodiation-desodiation process, which is conducive to the stable cycling of Na-ions.

Direct carbonization of sodium lignosulfonate through self-template strategies for the synthesis of porous carbons toward supercapacitor applications

Commercial supercapacitors rely on expensive porous carbon electrode materials. Therefore, it is essential to search for low-cost porous carbon electrode materials for next-generation supercapacitors. In this work, we produced lignin-derived porous carbon from alkalized sodium lignosulfonate. The carboxyl and phenolic hydroxyl are bonded with potassium ions in alkalized sodium lignosulfonate molecules. As a result, the introduced potassium ions on carboxyl and phenolic hydroxyl groups and sodium ions on sulfonate groups act as the porogens for preparing porous carbons. The alkalized sodium lignosulfonate is pyrolysis carbonized to produce porous carbon materials for asymmetric and symmetric supercapacitors. Developed pores inside the lignin-derived porous carbons are generated from the self-template role of the generated inorganic metal carbonates and metal sulfates. The introduced alkali metal ions in alkalized sodium lignosulfonate play extra roles of templates. Our work made a new paradigm shift that lignin could be transformed into porous carbon electrodes through self-template methodologies for future supercapacitor applications.

Lignin Derived Porous Carbons: Synthesis Methods and Supercapacitor Applications.

Lignin, one of the renewable constituents in natural plant biomasses, holds great potential as a sustainable source of functional carbon materials. Tremendous research efforts have been made on lignin-derived carbon electrodes for rechargeable batteries. However, lignin is considered as one of the most promising carbon precursors for the development of high-performance, low-cost porous carbon electrode materials for supercapacitor applications. Yet, these efforts have not been reviewed in detail in the current literature. This review, therefore, offers a basis for the utilization of lignin as a pivotal precursor for the synthesis of porous carbons for use in supercapacitor electrode applications. Lignin chemistry, the synthesis process of lignin-derived porous carbons, and future directions for developing better porous carbon electrode materials from lignin are systematically reviewed. Technological hurdles and approaches that should be prioritized in future research are presented.

Transformation of waste cornstalk into versatile porous carbon adsorbent for selective CO2 capture and efficient methanol adsorption

For the purpose of selective CO2 capture and efficient methanol adsorption, versatile porous carbon adsorbents are prepared from waste cornstalk by using hydrothermal carbonization treatment and the subsequent KOH activation process. The resultant adsorbents are characterized with different techniques, and the effects of activation degree on the porous structure and chemical components are discussed. The influence of porous texture and heteroatoms doping on the performance of CO2 capture and methanol adsorption has been systematically analyzed. For CO2 capture, the ultra-micropore is the dominant factor under 1 bar, while the heteroatoms N and O have important cooperation effect under 0.15 bar. The methanol adsorption uptakes under 95 mbar and 10 mbar are closely associated with the specific surface area and ultra-micropore volume, respectively. The adsorbents exhibit remarkable CO2 adsorption uptake of 3.97 mmol g−1 at 1 bar, and desirable methanol adsorption uptake of 18.88 mmol g−1 at 95 mbar, in the temperature of 25 °C. The adsorbents also feature excellent reusability and good selectivity for CO2 over N2, as well as methanol over water. This work provides a feasible approach to prepare low-cost porous carbon adsorbents, which may inspire new research interests and provide necessary theoretical guidance for the application and investigation of biomass-derived carbonaceous adsorbents for CO2 capture and methanol adsorption.

Relationship between microstructure and electrochemical properties of 2lignin-derived carbon nanofibers prepared by thermal treatment

Low-cost porous carbon nanofibers with MnO2 are developed via simple and inexpensive processes by using lignin as an affordable carbon precursor and generator of porous structures through one-step electrospinning and carbonization without requiring any other activating agent and process. The lignin-based carbon nanofiber/MnO2 composites carbonized at high temperature have a high mesoporosity induced by pore opening effect, and thus exhibit a high capacitance retention of 87 % and optimum cycling stability with 93 % retention due to the excellent chemical reversibility. Further, the large surface area with many micropores derived from the low carbonization temperature affords high capacitive performance with a maximum specific capacitance of 212 Fg−1 at low current density and a high energy density of 26.5 Whkg−1 at a power density of 400 Wkg−1. These eco-friendly, low-cost, and pore-controlled MnO2/CNF composites have been designed with optimized carbonization temperature and lignin addition to enhance their capacitive properties.

A green route for pyrolysis poly-generation of typical high ash biomass, rice husk: Effects on simultaneous production of carbonic oxide-rich syngas, phenol-abundant bio-oil, high-adsorption porous carbon and amorphous silicon dioxide

Rice husk is a widespread agriculture waste in rice-farming country. High silica content in rice husk prevent its efficient utilization. So in this work, concept of poly-generation was introduced to improve its utilization value. This study provided CO-rich syngas, phenol-abundant bio-oil, high-adsorption porous carbon and amorphous SiO2 as four end products for first time via combination of acid washing and activated carbon catalyst. Specifically, acid washing effectively decreasedsoluble ash, which altered pyrolysis paths, increased volatiles release and reduced impurities in bio-char. After catalytic pyrolysis, phenol content of 65.56% and CO of 56.09 vol% were detected in bio-oil and syngas from AWRH. For solid products, acid washing benefited both bio-char and silica. A low-cost porous carbon with developed pores and rich surface functional groups was prepared for water absorption. And high purity amorphous SiO2 was recycled from alkali etching solution. Finally, a green process with no waste emission was proposed.

Hierarchical porous activated carbon derived from Enteromorpha prolifera for superior electrochemical capacitive behavior

A low-cost porous carbon material is introduced by using marine bloom green alga—Enteromorpha prolifera—as raw material towards simple freeze-drying pretreatment and subsequent ZnCl2 activation procedure. This strategy is aimed at producing activated carbons with high surface area (1910.84 m2 g−1) and combining macro-/meso-/micropores with high total pore volume (up to 2.86 cm3 g−1), at a ZnCl2/E. prolifera impregnation ratio of 4 at 600 °C. The application of the activated carbons operating in electric double-layer capacitors (EDLCs) shows high specific capacitance of 332.4 F g−1 at a rate of 0.2 A g−1 in 1 M H2SO4, much better than those in 6 M KOH (167 F g−1). Moreover, the assembled symmetric devices yielded ultra-long cycling performance (100% after 5500 cycles at 0.5 A g−1). Benefiting from the cheap biomass precursor, we believe that this simple precursor synthesis route offers excellent potential for facile large-scale material production which may serve as a potential candidate for energy storage.

Biomass-derived nitrogen and oxygen co-doped hierarchical porous carbon for high performance symmetric supercapacitor

Carbon-based supercapacitor is one of the most promising energy conversion devices due to its ultrahigh power density and superior cycling durability, but most of carbon materials for high performance supercapacitor may involve high cost, sophisticated chemical procedures or tedious fabrication processes. Herein, a reproducible biomass-derived porous carbon with efficient ion-accessible surface and high content of heteroatoms has been successfully prepared by a simple high-temperaturepyrolysis process. The facile chemical activation enables the as-synthesized materials own a hierarchical porous structure with an ideal pore size distribution and high contents of nitrogen (0.99 at%) and oxygen (8.99 at%), which is conducive to the high-efficiency transfer of electrolyte ions and enhancement in electrical conductivity of the materials. The as-fabricated hierarchical porous carbon materials deliver excellent specific capacitance of 287.1 F g−1 at 1 A g−1 and admirable cycling durability of 99.0% at current density of 1 A g−1 after 10,000 cycles in 6.0 M KOH electrolyte. Remarkably, the assembled symmetric supercapacitor exhibits an excellent energy density of 43.0 Wh kg−1 at power density of 875.0 W kg−1 in ionic liquid electrolyte. This study shows that low cost porous carbon materials derived from biomass source by a facile pyrolysis might be a great option to fabricate high performance energy conversion device.

Direct carbonization of rice husk to prepare porous carbon for supercapacitor applications

Searching low-cost porous carbon is crucial for the future development of supercapacitors in a wide application range. In this paper, rice husk derived carbon (RHC) was prepared through direct carbonization of rice husk in a tube furnace without inlet of N2. RHC possesses relatively high pore volume, specific surface area and specific capacitance. The high specific surface area of RHC is attributed to the self-activation of rice husk by H2O, CO2 produced in the carbonization process. RHC was further treated by alkali etching to prepare a porous carbon (referred as RHPC). Owing to the removing of SiO2 in RHC, RHPC exhibits higher specific surface area and specific capacitance than RHC.

Evaluating the Storage Behavior of Superior Low-Cost Anode Material from Biomass for High-Rate Sodium-Ion Batteries

The superior low-cost porous carbon (SLPC) with an expanded interlayer spacing of 0.39 nm and a high surface area of ∼685 m2 g−1 was obtained by a direct pyrolysis of dried camphor wood without additional activation. Benefiting from the expanded interlayer spacing and high surface area, the obtained carbon exhibited an excellent electrochemical sodium ion storage performance with a high reversible capacity of ∼310 mAh g−1 after 100 cycles between 3.0 and 0.01 V (vs Na+/Na) at a constant current density of ∼0.1 A g−1. More importantly, an excellent rate capability of ∼120.6 mAh g−1 after 5000 cycles was delivered at a rather high current density of 5 A g−1, which is almost the best among the biomass-derived carbon anodes. The excellent performance of SLPC for SIBs may be attributed to the fast capacitance behavior and rapid mass transfer process profiting from porous structure of the carbon existing in biological tissue. Considering the superior low cost and excellent electrochemical sodium storage performance of SLPC, the SLPC might be a highly promising anode material for the practical application of SIBs.

From black liquor to highly porous carbon adsorbents with tunable microstructure and excellent adsorption of tetracycline from water: Performance and mechanism study

In this work, we reported the successful conversion of the industrial SLS originated from black liquor to low-cost porous carbon with tunable microstructure and ultrahigh adsorption performance of tetracycline (TC) from water via pre-carbonation and KOH activation. Comparatively, LCA-850-4 with a very high specific surface area (2805.8m2/g) and pore volume (1.45cm3/g) showed a maximum adsorption of 1173mg/g at 298K, which was far higher than other reported adsorbents. LCA-850-4 exhibited excellent adsorption over a broad pH range. Kinetics and isotherm data was well fitted to the pseudo-second-order rate and Langmuir model, respectively. Thermodynamic parameters indicated a spontaneous and endothermic adsorption. The results are of importance to indicate LCA-850-4 with fast kinetics and excellent reusability possessed the huge potentials in practical pharmaceutical antibiotic wastewater treatment.

Porous Carbon Nanofibers from Electrospun Biomass Tar/Polyacrylonitrile/Silver Hybrids as Antimicrobial Materials.

A novel route to fabricate low-cost porous carbon nanofibers (CNFs) using biomass tar, polyacrylonitrile (PAN), and silver nanoparticles has been demonstrated through electrospinning and subsequent stabilization and carbonization processes. The continuous electrospun nanofibers had average diameters ranging from 392 to 903 nm. The addition of biomass tar resulted in increased fiber diameters, reduced thermal stabilities, and slowed cyclization reactions of PAN in the as-spun nanofibers. After stabilization and carbonization, the resultant CNFs showed more uniformly sized and reduced average diameters (226-507 nm) compared to as-spun nanofibers. The CNFs exhibited high specific surface area (>400 m(2)/g) and microporosity, attributed to the combined effects of phase separations of the tar and PAN and thermal decompositions of tar components. These pore characteristics increased the exposures and contacts of silver nanoparticles to the bacteria including Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli, leading to excellent antimicrobial performances of as-spun nanofibers and CNFs. A new strategy is thus provided for utilizing biomass tar as a low-cost precursor to prepare functional CNFs and reduce environmental pollutions associated with direct disposal of tar as an industrial waste.