H3PO4/KOH Activation Agent for High Performance Rice Husk Activated Carbon Electrode in Acidic Media Supercapacitors

Barakat, Nasser A.M.; Irfan, Osama M.; Moustafa, Hager M.

doi:10.3390/molecules28010296

Cited by 15 publications

(7 citation statements)

References 89 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…According to Liou et al 26 , around 84% of the metallic impurities could be extracted by refluxing the graphitized rice husk with 3 N HCl at 100 °C for 1 h. As can be concluded from Fig. 1 B, utilizing of phosphoric acid after the carbonization process resulted in dissolution the metallic impurties from the produced char which in consistient with the other reports 42 , 43 . Accordingly, it can be claimed that, to maintain some metallic compounds in the rice husk-originated activated carbon, it is recommended to utlize the acid before the carbonization step.…”

Section: Resultsmentioning

confidence: 72%

Comparing specific capacitance in rice husk-derived activated carbon through phosphoric acid and potassium hydroxide activation order variations

Barakat,

Mahmoud,

Moustafa

2024

Sci Rep

Self Cite

View full text Add to dashboard Cite

This manuscript investigates the influence of the chemical activation step order and process parameters on the specific capacitance of activated carbon derived from rice husk. The chemical activation was performed either before or after the carbonization step, using phosphoric acid (H3PO4) and potassium hydroxide (KOH) as activating agents. For activation before carbonization, the carbonization process was conducted at various temperatures (600, 750, 850, and 1050 °C). On the other hand, for activation after carbonization, the effect of the volume of the chemical agent solution was studied, with 0, 6, 18, 21, 24, and 30 mL/g of phosphoric acid and 0, 18, 30, 45, 60, and 90 mL/g of 3.0 M KOH solution. The results revealed that in the case of chemical activation before carbonization, the optimum temperature for maximizing specific capacitance was determined to be 900 °C. Conversely, in the case of chemical activation after carbonization, the optimal volumes of the chemical agent solutions were found to be 30 mL/g for phosphoric acid (H3PO4) and 21 mL/g for potassium hydroxide (KOH). Moreover, it was observed that utilizing phosphoric acid treatment before the carbonization step leads to an 21% increase in specific capacitance, attributed to the retention of inorganic compounds, particularly silica (SiO2). Conversely, when rice husks were treated with KOH after the carbonization step, the specific capacitance was found to be doubled compared to treatment with KOH prior to the carbonization step due to embedding of SiO2 and KHCO3 inorganic constituents. This study provides valuable insights into the optimization of the chemical activation step order and process parameters for enhanced specific capacitance in rice husk-derived activated carbon. These findings contribute to the development of high-performance supercapacitors using rice husk as a sustainable and cost-effective precursor material.

show abstract

Section: Resultsmentioning

confidence: 72%

Comparing specific capacitance in rice husk-derived activated carbon through phosphoric acid and potassium hydroxide activation order variations

Barakat,

Mahmoud,

Moustafa

2024

Sci Rep

Self Cite

View full text Add to dashboard Cite

show abstract

“…64,65 Furthermore, the metallic potassium interacted with the cellulose cell wall, extending the space between carbon atomic layers, which was the driving force for generating increased total pore volume. 62 On the contrary, activated and carbonized carbon from NaOH-treated jute were noticed less porous than that of untreated jute. In pretreatment with NaOH, hemicellulose and lignin were removed, and the cross section became denser, resulting in a less porous structure.…”

Section: Resultsmentioning

confidence: 95%

“…The general mechanism of activating carbon with chemical agents such as H 3 PO 4 and KOH relies on the destruction of cellulose structures followed by char formation and aromatization of the carbon skeleton. 62 It was observed that a honeycomb-like porous structure was created after chemical activation. The blocked pores in carbonized carbon were opened after chemical activation.…”

Section: Resultsmentioning

confidence: 99%

Synthesis, Activation, and Characterization of Carbon Fiber Precursor Derived from Jute Fiber

Hossen,

Islam,

Hoque

et al. 2024

ACS Omega

View full text Add to dashboard Cite

Activated carbon (AC) fiber is a carbonaceous material with a porous structure that has a tremendous scope of application in different fields. Conventionally, AC is derived from fossil fuel-based raw materials like polyacrylonitrile (PAN) and pitch. In this work, AC was synthesized from ecofriendly, renewable, and ubiquitous jute fiber. Systematically, the jute fiber was washed and pretreated with NaOH. Raw jute and NaOH-treated jute were carbonized/pyrolyzed at 500 °C for 1 h in presence of N 2 gas. The carbonized carbon was activated with H 3 PO 4 and KOH and again pyrolyzed at 650 °C for 1.5 h maintaining the inert condition. The different features of activated carbons were characterized with field emission-scanning electron microscope, energy-dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), X-ray diffraction (XRD), and thermogravimetric analysis. The average yield of carbonized and activated carbons was recorded at 19 and 13.8%, respectively. The scanning electron microscopic images confirmed a honeycomb-like porous structure. It was observed that KOH-activated carbon exhibited a more porous structure than the H 3 PO 4 -activated carbons. The average pore diameter of activated carbons was noted to be 1.3 μm. The pore density was higher in case of KOH-activated carbons accounting for 2.15 pore/μm. The EDX analysis showed that H 3 PO 4 -activated carbons had more than 90% carbon atoms indicating a significant carbon content. The TEM images revealed that AC particles were in the nanoscale range. The average particle sizes of H 3 PO 4 -activated carbon and KOHactivated carbon were 36.38 and 32.8 nm, respectively. The XRD study demonstrated the highly disordered and low level of crystallinity of AC. It was detected that the AC showed much higher thermal resistance than the jute fiber. The H 3 PO 4 -activated carbon obtained from NaOH-treated jute remained at 84% even after 500 °C. A higher thermal resistance was achieved with H 3 PO 4activated carbon since it contains 0.56% phosphorus, which was confirmed by EDX investigation. It was found that a higher carbon yield was obtained from NaOH-treated jute. The porous structure of the material showed that it could be used as an adsorbent. Due to its high thermal stability, it is recommended for flame retardants and heat insulation applications as well.

show abstract

“…Furthermore, the interplay between metallic potassium and the carbon matrix widens the gap between carbon atomic layers, raising the overall pore volume. whereas phosphoric acid exhibits an intriguing performance as an activating agent because of its propensity to adhere to biomaterials and break them down thereafter. − The impact of various activation temperatures and activating agents on the electrochemical performance and stability of coconut-husk-derived electrodes and their long-term LED powering has not been the subject of any of the current investigations.…”

Section: Introductionmentioning

confidence: 99%

Effect of Activation Environment on Coconut-Husk-Derived Porous Activated Carbon for Renewable Energy Storage Applications

Tomy,

Geethamma,

Aravind

et al. 2024

ACS Sustainable Resour. Manage.

View full text Add to dashboard Cite

As a major agro waste of coconut, coconut husk is presented here as a cheap, abundant, novel, and sustainable green source of high-surface-area activated carbon for high-performance supercapacitor electrodes. The present communication satisfies one of the United Nations Sustainable Development Goals (UN goals) as an affordable, reliable, and sustainable solution for the existing energy technologies. The carbonization and the activation via a one-step integrated microwave pyrolysis system and vacuum furnace, respectively, are the production technologies used for the conversion of biomass into activated carbon. The chemical impregnation was performed in two different agents (KOH and H 3 PO 4 ) and three higher activation temperatures (700, 800, and 900 °C), and their physical properties and the supercapacitive performances were analyzed and compared. A high surface area of 1218 m 2 g −1 was achieved for KOH impregnation (AC KOH 900) with a weight ratio of AC to KOH of 1:2 at an activation temperature of 900 °C, yielding an excellent specific capacitance of 342 F g −1 , much higher than that of activated carbon with H 3 PO 4 activation (243 F g −1 ). The energy storage performance was further carried out by fabricating a symmetric supercapacitor device in aqueous and polymer gel (PVA-H 3 PO 4 ) electrolyte media, and excellent cyclic stability of nearly 100% was achieved with high power density for both KOH-and H 3 PO 4 -activated samples at high temperature, which can be interconnected with its enhanced surface area and high porosity that facilitates fast ion transport and improves energy storage performance. The fabricated supercapacitor cells, when used to power two red LEDs, showed a complete discharge at the end of 15 min while a maximum glow for 30 min was achieved for a single LED, which took 1 h for its complete discharge. Furthermore, via the present investigation, coconut-husk-derived activated carbon shows promise as a high capacitance, low cost, and renewable material, consequently suggesting a promising avenue toward high-power, affordable, renewable, and clean energy storage devices.

show abstract

H3PO4/KOH Activation Agent for High Performance Rice Husk Activated Carbon Electrode in Acidic Media Supercapacitors

Cited by 15 publications

References 89 publications

Comparing specific capacitance in rice husk-derived activated carbon through phosphoric acid and potassium hydroxide activation order variations

Comparing specific capacitance in rice husk-derived activated carbon through phosphoric acid and potassium hydroxide activation order variations

Synthesis, Activation, and Characterization of Carbon Fiber Precursor Derived from Jute Fiber

Effect of Activation Environment on Coconut-Husk-Derived Porous Activated Carbon for Renewable Energy Storage Applications

Contact Info

Product

Resources

About