Electrocatalytic Oxidation of Formaldehyde onto Carbon Paste Electrode Modified with Nickel Decorated Nanoporous Cobalt‐Nickel Phosphate Molecular Sieve for Fuel Cell

Nanoporous cobalt‐nickel phosphate VSB‐5 molecular sieve (CoVSB‐5) was synthesized by conventional heating for 48 h in the presence of (2‐hydroxyethyl) trimethylammonium hydroxide as template. Then, a novel, cheap and efficient catalyst was developed for formaldehyde electrooxidation by decorating Ni²⁺ ions on the surface of CoVSB‐5 modified carbon paste electrode (CoVSB‐5/CPE). The electrochemical behavior of the Ni‐CoVSB‐5/CPE electrode towards the formaldehyde oxidation was evaluated by cyclic voltammetry (CV) as well as chronoamperometry methods. An oxidation peak was observed at 0.60 V in 0.1M NaOH solution for electrocatalytic oxidation of formaldehyde with EC′ mechanism. It has been observed that CoVSB‐5 at the surface of CPE can improve catalytic efficiency of the dispersed nickel ions toward oxidation of formaldehyde. The values of electron transfer coefficient, the mean value of catalytic rate constant and diffusion coefficient for formaldehyde and redox sites were obtained to be 0.66, 1.80 × 10⁵ cm³ mol⁻¹ s⁻¹ and 3.62 × 10⁻⁴ cm² s⁻¹, respectively. Obtained results from cyclic voltammetry (CV) and chronoamperometry techniques specified that the electrode reaction is a diffusion‐controlled process. The good catalytic activity, high sensitivity, good selectivity and stability and easy in preparation rendered the Ni‐CoVSB‐5/CPE to be a capable electrode for formaldehyde electrooxidation.     

Hydrothermal and soft-templating synthesis of mesoporous NiCo2O4 nanomaterials for high-performance electrochemical capacitors

Mesoporous nickel cobaltite (NiCo₂O₄) nanoparticles were synthesized via a hydrothermal and soft-templating method through quasi-reverse-micelle mechanism. The physicochemical properties of the NiCo₂O₄ materials were characterized via X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectra, and nitrogen sorption isotherms measurements. The electrochemical performances of the NiCo₂O₄ electrode were investigated by cyclic voltammetry, chronopotentiometry, and electrochemical impedance spectroscopy tests. The obtained NiCo₂O₄ materials exhibit typical mesoporous structures, with an average particle size of about 200 nm, a specific surface area of 88.63 m² g^?1, and a total pore volume of 0.337 cm³ g^?1. The facile electrolytes penetration for the mesoporous structures favors high-performance of the NiCo₂O₄ electrode. The NiCo₂O₄ electrode shows a high specific capacitance (591 F g^?1 at 1 A g^?1), high-rate capability (248 F g^?1 at 20 A g^?1), and a good cycling behavior for tested 3,000 cycles, indicating a promising application for electrochemical capacitors.     

Electrodeposition and characterization of nickel–copper metallic foams for application as electrodes for supercapacitors

Nickel–copper metallic foams were electrodeposited from an acidic electrolyte, using hydrogen bubble evolution as a dynamic template. Their morphology and chemical composition was studied by scanning electron microscopy and related to the deposition parameters (applied current density and deposition time). For high currents densities (above 1 A cm^?2) the nickel–copper deposits have a three-dimensional foam-like morphology with randomly distributed nearly-circular pores whose walls present an open dendritic structure. The nickel–copper foams are crystalline and composed of pure nickel and a copper-rich phase containing nickel in solid solution. The electrochemical behaviour of the material was studied by cyclic voltammetry and chronopotentiometry (charge–discharge curves) aiming at its application as a positive electrode for supercapacitors. Cyclic voltammograms showed that the Ni–Cu foams have a pseudocapacitive behaviour. The specific capacitance was calculated from charge–discharge data and the best value (105 F g^?1 at 1 mA cm^?2) was obtained for nickel–copper foams deposited at 1.8 A cm^?2 for 180 s. Cycling stability of these foams was also assessed and they present a 90 % capacitance retention after 10,000 cycles at 10 mA cm^?2.     

Porous Co3O4 nanorods as superior electrode material for supercapacitors and rechargeable Li-ion batteries

Porous aggregated nanorods of Co₃O₄ with a surface area of ~100 m² g^?1 synthesized without using any templates or surfactants give very high specific capacitance of ~780 F g^?1 when used as electrode in a faradaic supercapacitor, with a cycle life of more than 1,000 cycles. Further, in Li-ion batteries when used as an anode, the Co₃O₄ nanorods achieved a capacity of 1155 mA h g^?1 in the first cycle and upon further cycling it is stabilized at 820 mA h g^?1 for more than 25 cycles. Detailed characterization indicated the stability of the material and the improved performance is attributed to the shorter Li-insertion/desertion pathways offered by the highly porous nanostructures. The environmentally benign and easily scalable method of synthesis of the porous Co₃O₄ nanorods coupled with the superior electrode characteristics in supercapacitors and Li-ion batteries provide efficient energy storage capabilities with promising applications.     

Application of attapulgite/maltose system on mesoporous carbon material preparation for electrochemical capacitors

Mesoporous carbon materials were prepared through atmospheric pressure impregnation at room temperature using attapulgite as hard template and maltose as carbon source. N₂ absorption–desorption, X-ray diffraction, and transmission electron microscopy were used to determine the construction and morphology of the materials. The results showed that the prepared carbon materials possessed chain-layered structures whose surfaces were filled with ample nanoscale apertures. The materials also exhibited partial fasciculus with specific surface area and total pore volume of 628.6 m² g^?1 and 1.31 cm³ g^?1, respectively. Constant current charge/discharge, cyclic voltammetry, and AC impedance tests were performed to evaluate the electrochemical performance of the materials. The constant current charge/discharge tests showed that the materials have excellent energy storage capacity. When the current density was 600 mA g^?1, the specific capacitance value reached 171 F g^?1. The materials showed quasi-rectangular features of typical cyclic voltammetry curve even at high scan rate (200 mV s^?1), indicating that they possess excellent rate capacity. The AC impedance tests showed that the materials were typical porous electrode materials with combination resistance of 0.82 Ω. The specific capacitance of the materials reached 79 % after 1,000 constant current charge/discharge cycles, indicating that they have superior cyclic stability.     

A comparative study to evaluate the corrosion performance of Zr incorporated Cr3C2-(NiCr) coating at 900 °C

In this study zirconium incorporated Cr₃C₂-(NiCr) coating has been sprayed on three superalloys viz. Superni 718, Superni 600 and Superco 605 using D-gun technique. A comparative study has been carried out to check the cyclic oxidation in air and hot corrosion in simulated incinerator environment (40%Na₂SO₄-40%K₂SO₄-10%NaCl-10%KCl) for the coated specimens at 900 °C for 100 cycles. Oxidation kinetics has been established for all the specimens using weight change measurements. Corrosion products have been characterized using X-ray diffractometer (XRD) and scanning electron microscopy/energy-dispersive analysis (SEM/EDAX). Cr₃C₂-(NiCr) + 0.2%wtZr coating provides very good corrosion resistance in air oxidation for all the three coated superalloys. As all the three coated superalloys shows parabolic behaviour with parabolic rate constant as 0.07 × 10^?10 (g² cm^?4 s^?1) for Superni 718, 0.43 × 10^?10 (g² cm^?4 s^?1) for Superni 600 and 0.3 × 10^?10 (g² cm^?4 s^?1) for Superco 605 This coating is also effective in the molten salt environment but coating on Co-based superalloy Superco 605 did not perform satisfactorily. The parabolic rate constants for coated Superni 718 is 0.61 × 10^?10 (g² cm^?4 s^?1), for coated Superni 600 is 6.72 × 10^?10 (g² cm^?4 s^?1) and for coated Superco 605 is 17.5 × 10^?10 (g² cm^?4 s^?1).     

Ag nanowires and its application as electrode materials in electrochemical capacitor

Silver nanowires were synthesized on a large scale by using anodic aluminum oxide (AAO) film as templates and serving ethylene glycol as reductant. Their morphological and structural characterizations were characterized with field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and selected area electron diffraction (SAED). The electrochemical properties of silver nanowires as electrode materials for electrochemical capacitors were investigated by cyclic voltammetry (CV) and galvanostatic charge/discharge technique in 6 M KOH aqueous electrolyte. The Ag₂O/Ag coaxial nanowires were formed by the incomplete electrochemical oxidation during the charge step. The maximum specific capacitance of 987 F g^?1 was obtained at a charge–discharge current density of 5 mA cm^?2.     

Ordered mesoporous carbon prepared from triblock copolymer/novolac composites

Ordered mesoporous carbon is synthesized by the organic–organic self-assembly method with novolac as carbon precursor and two kinds of triblock copolymers (Pluronic F127 and P123) as template. The hexagonal structure and a worm-hole structure are observed by TEM. The carbonization temperature is determined by TG and FT-IR. Characterization of physical properties of mesoporous carbon is executed by N₂ absorption–desorption isotherms and XRD. The mass ratios of carbon precursor/template affect the textural properties of mesoporous carbon. The mesoporous carbon with F127/PF of 1/1 has lager surface area (670 m² g^?1), pore size (3.2 nm), pore volume (0.40 cm³ g^?1), smaller microporous surface area (368 m² g^?1) and wall thickness (3.7 nm) compare to that with F127/PF of 0.5/1 (576 m² g^?1, 2.7 nm, 0.29 cm³ g^?1, 409 m² g^?1 and 4.3 nm, respectively). The mesoporous carbon prepared by carbonization at high temperature (700 °C) exhibits lager surface area, lower pore size and pore volume than the corresponding one obtained at 500 °C. The structure and order of the resulting materials are notably affected with types of templates. The mesoporous carbon with P123 as template exhibits worm-hole structure compare to that with F127 as template with hexagonal structure. In general, the pore size of mesoporous carbon with novolac as precursor is smaller than that with resorcinol–formaldehyde as precursor.     

The efficient removal of dyes over magnetic Ni embedded on mesoporous graphitic carbon material

Magnetically separable Ni embedded on graphitic mesoporous carbon (NMC) material was fabricated through a facile “sol–gel” route using glucose, nickle nitrate, poly(ethylene glycol)–poly(propylene glycol)–poly(ethylene glycol) (P123) and tetraethyl orthosilicate as carbon source, catalyst and magnetic precursor, soft template and porogen. The obtained NMC material exhibited highly graphitic degree with high surface area of 790 m² g^?1, large pore size at 3.9 nm and pore volume of 0.69 cm³ g^?1. The saturation magnetization was enhanced to 6.82 emu g^?1 because of aggregation of magnetic Ni particles to clusters. NMC material showed excellent removal to Rhodamine B and the adsorption capacity reached to 168.1 mg g^?1 within 120 min. NMC material could be easily separated by an external magnet and reused after ethanol extraction.     

Fluidized‐bed CVD of unstacked double‐layer templated graphene and its application in supercapacitors

Graphene is inclined to stack with each other that greatly hinders the full utilization of its intrinsic extraordinary properties. Introducing protuberant spacers is a straightforward strategy to avoid the stacking of graphene nanosheets, resulting in a novel unstacked double‐layer templated graphene (DTG) structure. Herein, a family of layered double hydroxides were used for the bulk chemical vapor deposition (CVD) of DTG in a fluidized‐bed reactor. A high specific surface area of 1554.2 m² g^?1 and a large pore volume of 1.70 cm³ g^?1 were achieved. When used as the electrode material for supercapacitors, the DTG afforded a specific capacitance of 65.5 F g^?1 at a sweep rate of 5.0 mV s^?1 and a capacitance retention of 77% when the sweep rate was increased to 500 mV s^?1. Therefore, the DTG obtained via fluidized bed CVD is a promising electrode material for supercapacitor applications. © 2014 American Institute of Chemical Engineers AIChE J, 61: 747–755, 2015     

Hydrogen peroxide sensor based on riboflavin immobilized at the nickel oxide nanoparticle-modified glassy carbon electrode

A simple and sensitive electrochemical sensor based on nickel oxide nanoparticles/riboflavin-modified glassy carbon (NiONPs/RF/GC) electrode was constructed and utilized to determine H₂O₂. By immersing the NiONPs/GC-modified electrode into riboflavin (RF) solution for a short period of time (5–300 s), a thin film of the proposed molecule was immobilized onto the electrode surface. The modified electrode showed stable and a well-defined redox couples at a wide pH range (2–10), with surface-confined characteristics. Experimental results revealed that RF was adsorbed on the surface of NiONPs, and in comparison with usual methods for the immobilization of RF, such as electropolymerization, the electrochemical reversibility and stability of this modified electrode has been improved. The surface coverage and heterogeneous electron transfer rate constants (k _s) of RF immobilized on a NiO _x –GC electrode were approximately 4.83 × 10^?11 mol cm^?2, 54 s^?1, respectively. The sensor exhibits a powerful electrocatalytic activity for the reduction of H₂O₂. The detection limit, sensitivity and catalytic rate constant (k _cat) of the modified electrode toward H₂O₂ were 85 nM, 24 nA μM^?1 and 7.3 (±0.2) × 10³ M^?1 s^?1, respectively, at linear concentration rang up to 3.0 mM. The reproducibility of the sensor was investigated in 10 μM H₂O₂ by amperometry, the value obtained being 2.5 % (n = 10). Furthermore, the fabricated H₂O₂ chemical sensor exhibited an excellent stability, remarkable catalytic activity and reproducibility.     

Preparation and molten salt-assisted KOH activation of porous carbon nanofibers for use as supercapacitor electrodes

Carbon nanofiber paper was prepared by electrospinning from thermosetting phenolic resin, followed by activation via KOH-containing molten salt at high temperature. By adding a small dosage of KOH in the molten salt the porous volume and specific surface area could be greatly improved. The obtained porous carbon nanofibers had a specific surface area of 1007 m² g^?1, total pore volume of 0.363 cm³ g^?1, micropore volume of 0.247 cm³ g^?1. The electrochemical measurements in 6 M KOH aqueous solution showed that the porous carbon nanofibers possessed high specific capacitance and considerable rate performance. The maximal specific capacitance of 288 F g^?1 was achieved at 0.2 A g^?1 and the specific capacitance could still remain 204 F g^??1 at 20 A g^?1 with the retention of 71%. In the molten salt system, the reaction between activating agent and carbon could be more efficient, hence, such molten salt-assisted activation method was considered as a general activation method for the high-specific-surface-areaed carbons.     

Preparation of high surface area mesoporous nickel oxides and catalytic oxidation of toluene and formaldehyde

Mesoporous nickel oxide (NiO) nanoparticles were synthesized by the thermal decomposition reaction of Ni(NO₃)₂·9H₂O using oxalic acid dihydrate as the mesoporous template reagent. The pore structure of nanocrystals could be controlled by the precursor to oxalic acid dihydrate molar ratio, thermal decomposition temperature and thermal decomposition time. The structural characteristic and textural properties of resultant nickel oxide nanocrytals were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), N₂ adsorption–desorption isotherm and temperature programmed reduction. The results showed that the most excellently mesoporous nickel oxide particles (m-Ni-1-4) with developed wormlike pores were prepared under the conditions of the mixed equimolar precursor and oxalic acid and calcined for 4 h at 400 °C. The specific surface area and pore volume of m-Ni-1-4 are 236 m² g^?1 and 0.42 cm³ g^?1, respectively. Over m-Ni-1-4 at space velocity = 20,000 mL g^?1 h^?1, the conversions of toluene and formaldehyde achieved 90 % at 242 and 160 °C, respectively. It is concluded that the reactant thermal decomposition with oxalic acid assist is a key step to improve the mesoporous quality of the nickel oxide materials, the developed mesoporous architecture, high surface area, low temperature reducibility and coexistence of multiple oxidation state nickel species for the excellent catalytic performance of m-Ni-1-4.     

High electrocatalysis of ethylene glycol oxidation based on nickel particles electrodeposited into poly (m-toluidine)/Triton X-100 composite

Poly (m-toluidine) (PMT) was formed by successive cyclic voltammetry in a monomer solution containing Triton X-100 (TX-100) at the surface of carbon paste electrode (CPE). Nickel was then incorporated into the polymer by electrodeposition of Ni(II) from NiSO₄ acidic solution. The electrochemical behavior of this modified electrode (Ni/PMT(TX-100)/MCPE) was investigated in the electrooxidation of ethylene glycol (EG) using cyclic voltammetry and chronoamperometry techniques. Among the electrodes [Ni/PMT(TX-100)/MCPE, Ni/PMT/MCPE, Ni/MCPE, PMT(TX-100)/MCPE, and CPE] used in this study, Ni/PMT(TX-100)/MCPE showed the most effective catalytic activity. The effects of various parameters such as film thickness, electrodepositing time, TX-100 concentration, MT concentration, and EG concentration were investigated on the electrocatalytic oxidation of EG at the surface of Ni/PMT(TX-100)/MCPE. The catalytic rate constant (k) for EG oxidation was also calculated to be 2.1 × 10⁶ cm³ mol^?1 s^?1 using a chronoamperometric method.     

Electrooxidation and inhibition of the antibacterial activity of oxytetracycline hydrochloride using a RuO<Subscript>2</Subscript> electrode

This work reports on the electrochemical oxidation of oxytetracycline hydrochloride (OTCH) [(4S,4aS,5aS,6S,12aS)-4-dimethylamino-1,4,4a,5, 5a,6,11,12a-octahydro-3,6,10,12,12a-hexahydroxy-6-methyl-1,11-dioxonaphthacene-2-carboxamide] on a RuO₂ electrode (DSA^®) by cyclic voltammetry and electrolysis. The electrocatalytic efficiency of the electrode material was investigated as a function of different aqueous buffer solutions with pH values of 2.10 and 5.45 as supporting electrolytes. Spectrophotometric studies have shown that OTCH is stable in such solutions. The electrochemical degradation of OTCH is pseudo-first order at both pH values investigated with rate constants, k, of 9.9 × 10^?5 s^?1 (pH 2.10) and 1.9 × 10^?4 s^?1 (pH 5.45) at 21 ± 1 °C. Microbiological studies with Staphylococcus aureus ATCC 29213 have shown that OTCH lost antibacterial activity after 120 min of electrolysis at 50 mA cm^?2.     

Electrochemical oxidation and determination of antiretroviral drug nevirapine based on uracil-modified carbon paste electrode

A novel uracil covalently grafted carbon paste electrode (Ura/CPE) based on electro-deposition of uracil on CPE was prepared for the quantitative determination of nevirapine. The records of electrochemical impedance spectroscopy (EIS) and cyclic voltammograms (CV) in K₃Fe(CN)₆/K₄Fe(CN)₆ solution illustrated that uracil grafted on CPE efficiently decreased the charge transfer resistance value of electrode and improved the electron transfer kinetic between analyte and electrode. The electrochemical properties of Ura/CPE towards the oxidation of nevirapine were investigated by cyclic voltammetry and differential pulse voltammetry (DPV) in 0.1 M NaOH. The effects of pH and scan rates on the oxidation of nevirapine were studied. The results indicated the participation of the same protons and electrons in the oxidation of nevirapine, and the electrochemical reaction of nevirapine on Ura/CPE is an adsorption-controlled process. Under optimized conditions, the linearity between the oxidation peak current and nevirapine concentration was obtained in the range of 0.1–70.0 μM with detection limit of 0.05 μM and the sensitivity of 2.073 μA mM^?1 cm^?2 (S/N = 3). The proposed method was also successfully applied to detect the concentration of nevirapine in human serum samples.     

Pore-size-tunable nitrogen-doped polymeric frameworks for high performance sodium ion storage and supercapacitors

Sodium-ion batteries (SIBs) is considered as a promising alternative to lithium-ion batteries. Supercapacitors (SCs) are receiving great attention for their significantly higher power density than batteries and prolonged cycle life. Herein, SIBs and SCs based on N-doped amorphous multi-size pores dominated polymeric frameworks were fabricated and examined. The enlarged interlayer spacing and multi-size-pore dominated interconnected architecture with high specific surface area, high pore volume and high N content optimize the electrochemical performance of N-PPF-20. As an anode material, N-PPF-20 exhibited a sodium ion storage capacity of 432.2 mAh g^?1 at a current density of 0.05 A g^?1, while maintaining a reversible capacity of 61.1 mAh g^?1 at an ultrahigh current density of 20 A g^?1. Additionally, a specific capacity of 158.3 mAh g^?1 at 1 A g^?1 was obtained after 1000 cycles, indicating an excellent cycling stability. When tested as an electrode material for SCs, N-PPF-20 delivered a high specific capacitance of 438.7 F g^?1 at 0.1 A g^?1, and a specific capacitance of 111.2 F g^?1 was achieved even at a high current density of 10 A g^?1. Meanwhile, a long-term cycling life test demonstrated a specific capacitance of 120 F g^?1 at an ultrahigh current density of 10 A g^?1 after 10,000 cycles.     

LiFePO4 batteries with enhanced lithium-ion-diffusion ability due to graphene addition

In this study, graphene was added to LiFePO₄ via a hydrothermal method to improve the lithium-ion-diffusion ability of LiFePO₄. The influence of graphene addition on LiFePO₄ was studied by X-ray diffraction (XRD), field emission scanning electron microscopy, transmission electron microscopy, cyclic voltammetry, cycling test, and AC impedance analysis. The addition of graphene to LiFePO₄ resulted in the formation of a LiFePO₄–graphene composite; XRD observations revealed the composite to have a single phase with an olivine-type structure. Furthermore, LiFePO₄ particles in the composite were stacked on the graphene sheet surface, thereby enabling the composite to form an effective conducting network and facilitate the penetration of the surface of active materials by an electrolyte. The lithium-ion-diffusion ability of the LiFePO₄–graphene composite was greater than that of pure LiFePO₄. Of a number of materials studied [namely, pure LiFePO₄, LiFePO₄–graphene (1 %), LiFePO₄–graphene (5 %), and LiFePO₄–graphene (8 %)], LiFePO₄–graphene (5 %) delivered the best electrochemical performance with a lithium-ion-diffusion coefficient of 8.18 × 10^?12 cm² s^?1 and the highest specific discharge capacity of 149 mAh g^?1 at 0.17 C; in contrast, the corresponding values for pure LiFePO₄ were 3.01 × 10^?12 cm² s^?1 and 109 mAh g^?1, respectively. Further, LiFePO₄–graphene (5 %) showed a very high specific discharge capacity of 170 mAh g^?1 at 0.1 C, which is equal to the theoretical capacity of LiFePO₄.     

The effect of halide ion concentration on capacitor performance

The effect of halide ion concentration on the capacitor performance was considered during this study. Iodide anion has been selected as the most profitable halide taking into account its electrochemical properties and environmental impact. Several concentrations of NaI were tested (from 0.25 to 5 mol L^?1 aqueous solutions) using as electrodes two commercial activated carbons and one KOH-activated carbon. Detailed electrochemical investigation by galvanostatic charging/discharging, cyclic voltammetry, and impedance spectroscopy confirmed the significant impact of iodide concentration on the supercapacitor behavior. The higher concentration of iodide affected especially the performance of positive electrode; increase of iodide concentration changed the potential range of positive electrode and its capacitance increased from 119 F g^?1 for 0.25 mol L^?1 NaI to 475 F g^?1 for 2 mol L^?1 NaI solution. The electrode capacitance measured in two-electrode system at current density of 2 A g^?1 ranged from 198 F g^?1 for 0.25 mol L^?1 NaI to 272 F g^?1 for 2 mol L^?1 NaI solution (capacitance expressed as average of the positive and negative electrode capacitances). It has been proved that 2 mol L^?1 alkali metal iodide solution is an optimal electrolyte for the capacitor based on KOH-activated carbon. High capacitance values and perfect stability (100 % retention) of such systems have been observed during long-term galvanostatic charging/discharging (15,000 cycles). In addition, satisfactory floating tests at extended voltage range (1.2 V) were performed.     

Activated carbon from cherry stones by chemical activation: Influence of the impregnation method on porous structure

Cherry stones are utilized as a precursor for the preparation of activated carbons by chemical activation with phosphoric acid (H₃PO₄). The activation process typically consists of successive impregnation, carbonization, and washing stages. Here, several impregnation variables are comprehensively studied, including H₃PO₄ concentration, number of soaking steps, H₃PO₄ recycling, washing of the impregnated material, and previous semi-carbonization. The choice of a suitable impregnation methodology opens up additional possibilities for the preparation of a wide variety of activated carbons with high yields and tailored porous structures. Microporous activated carbons with specific surface areas of ～800 m² g^?1 are produced, in which > 60% of the total pore volume is due to micropores. High surface areas of ～1500 m² g^?1 can be also developed, with micropore volumes being a 26% of the total pore volume. Interestingly, using the same amount of H₃PO₄, either carbons with surface areas of 791 and 337 m² g^?1 or only one carbon with a surface area of 640 m² g^?1 can be prepared. The pore volumes range very widely between 0.07–0.55, 0.01–0.90, and 0.09–0.79 cm³ g^?1 for micropores, mesopores, and macropores, respectively.