Article

Effectiveness of Kepok Banana (Musa paradisiaca) Bread-Based Adsorbent for

Fe(III) Removal Using HCl Activation: Freundlich and Langmuir Isotherm Models

Idha Silviyati *, Endang Supraptiah, Sri Murda Niati , Ibnu Hajar

Aisyah Suci Ningsih, Feby Nia Amalda

Chemical Engineering Department, Politeknik Negeri Sriwijaya, Palembang, Sumatera Selatan -30139,

Indonesia

Abstract

Activated carbon can be synthesized from lignocellulosic biomass, such as kepok banana (Musa

paradisiaca) stems, which are an abundant agricultural waste rich in cellulose (~64%). In this study, kepok

banana stems were utilized as a precursor to produce activated carbon using hydrochloric acid (HCl) as

the chemical activating agent. The activation process employed HCl concentrations of 1.5, 2.0, 3.0, 5.0,

and 7.0 N, with a carbonization temperature of 400°C for 1 hr and an Fe adsorption contact time of 30

minutes. The resulting activated carbon was evaluated based on its physicochemical properties

according to the Indonesian National Standard (SNI 06-3730-1995). The sample treated with 3.0 N HCl

showed optimal characteristics, including moisture content of 2.34%, ash content of 0.28%, volatile

matter content of 2.05%, and fixed carbon content of 95.33%. Its iodine number reached 1116.98ꢀmg/g,

and the Fe ion removal efficiency was 99.14%. FTIR spectroscopy confirmed the presence of functional

groups typical of activated carbon—O–H, aromatic C=C, C–H, and C–O—suggesting good adsorption

potential. Furthermore, adsorption behavior was analyzed using the Freundlich isotherm model, which

describes multilayer adsorption on heterogeneous surfaces. The findings demonstrate that activated

carbon derived from kepok banana stems is an effective, low-cost, and environmentally friendly

adsorbent for iron removal, suitable for applications in water purification and wastewater treatment.

Keywords: Activated carbon; kepok banana stem; Iron (Fe)

Graphical Abstract

*

Corresponding author

Email addresses: idha.silviyati@polsri.ac.id

DOI: https://doi.org/10.22437/chp.v9i1.44926

Received June 05^th2025; Accepted June 20^th2025; Available online June 30^th2025

(https://creativecommons.org/licenses/by/4.0 )

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Chempublish Journal, 9(1) 2025,130-140

(

)

V

C −C

o

e

Introduction

qe =

(1)

W

Activated carbon is a highly porous, amorphous

form of carbon widely utilized as an adsorbent in

purification, separation, and the removal of

contaminants from liquids and gases due to its

large surface area and high adsorption capacity

[1,2]. It can be produced from various

lignocellulosic biomass sources rich in cellulose,

such as the stems of kepok banana (Musa

paradisiaca), an abundant agricultural waste.

These banana stems contain approximately 64%

cellulose, along with hemicellulose (19%), lignin

(5%), and water (11%) [3,4]. Their composition

makes them a promising raw material for

producing activated carbon, supporting both

Notes:

q_e

Co

Ce

V

= Adsorption capacity (mg/g)

= Initial Fe concentration (mg/l)

= Final Fe concentration (mg/l)

= Sample volume (Liter)

W

= Adsorbent weight (grams)

1

푋

푚

푛

= 푘_푓.퐶푒

(2)

ꢀ

Equation 2 can be derived linearly into equation

3 [8].

Log (^푋_ꢀ^푚)= log 푘_푓+ ¹. log Ce

(3)

ꢁ

waste

valorization

and

environmental

sustainability.

Tabel 1. Requirements for Activated Charcoal

According to SNI No.06-3730-1995 [7]

The activation process significantly influences the

quality of activated carbon. Previous studies

using sodium hydroxide (NaOH) as an activating

agent yielded carbon with high ash content and

low iodine adsorption, thus failing to meet the

Indonesian National Standard (SNI 06-3730-

1995). In contrast, hydrochloric acid (HCl)

activation has been reported to produce better-

Quality Parameter (%)

Powder Quality

Standard

≤ 15 %

Water Content

Ash Content

≤ 10 %

Volatile Matter Content

Bound Carbon Content

Absorbency to Iodine

Absorbency to Benzene

≤ 25 %

≥ 65 %

≥ 750 mg/g

≥ 25 %

quality

activated

carbon

with

improved

adsorption performance and reduced ash

content, aligning with SNI requirements (Table 1)

[5].

The Langmuir isotherm, in contrast, assumes

monolayer adsorption on homogeneous

a

surface, with no interaction between adsorbed

molecules. It is expressed as equation 4 [11].

The Freundlich isotherm model is employed in

this study to describe adsorption behavior,

particularly the relationship between the

adsorbed metal ion concentration and the

equilibrium concentration in solution, assuming

푏 . ꢂ . ꢃ

qe = ^푋

=

(4)

푚

ꢄ

ꢀ

1+ꢂ . ꢃ

ꢄ

Equation (4) can be reduced linearly to equation

5 [8]

a

heterogeneous

surface

with

multilayer

ꢃ

1

ꢄ

=

+

. 퐶푒

(5)

adsorption. This study aims to synthesize

activated carbon from kepok banana stems using

HCl activation, characterize its physicochemical

properties, and evaluate its adsorption capacity

for Fe(III) ions, particularly in the context of water

and wastewater treatment applications.

푄

ꢂ . 푏

푏

Notes

Ce

= Equilibrium concentration of adsorbate

in solution after adsorption (mg/L)

= Amount of adsorbed adsorbate per

adsorbent weight (mg/g)

Q

Adsorption performance is often evaluated using

isotherm models. The Freundlich isotherm

k

b

= Adsorption equilibrium constant (L/mg)

= Maximum adsorption capacity of the

adsorbent (mg/g)

describes

multilayer

adsorption

on

heterogeneous surfaces, where the adsorption

capacity (qe) is related to the equilibrium

concentration (Ce) by the empirical equation 1

and 2 [9].

1/kb

1/b

= Intercept

= Slope

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Chempublish Journal, 9(1) 2025,130-140

In addition to isotherm studies, the surface

chemistry of activated carbon plays a pivotal role

in adsorption mechanisms. Fourier Transform

Infrared Spectroscopy (FTIR) is employed to

identify surface functional groups responsible for

adsorptive interactions. FTIR detects specific

procedures. Data analysis was conducted using

statistical

tabulation

and

graphical

interpretation. The main variable studied was the

concentration of HCl used as an activating agent

in the production of activated carbon from

banana stem biomass. The activated carbon

preparation process comprised three primary

stages: dehydration, carbonization, and chemical

activation. The fixed parameters included a

vibrational

frequencies

associated

with

functional groups such as hydroxyl (–OH),

carbonyl (C=O), carboxyl (–COOH), and aromatic

C=C bonds [12]. These functional groups are

critical for the interaction with metal ions or

organic pollutants. FTIR spectra typically exhibit

absorption bands near 3400 cm⁻¹ (–OH), 1700

cm⁻¹ (C=O), and 1600 cm⁻¹ (C=C), which serve as

indicators of surface chemistry modifications

following activation or adsorption processes.

carbonization

temperature

of

400ꢀ°C,

a

carbonization duration of 1 hr, activation time of

4 hr, stirring speed of 400ꢀrpm, mesh size of 70,

and a contact time of 30 min between activated

carbon and Fe(II) solution.

The preparation of activated carbon involved the

following sequential stages: (1) Carbonization:

Pre-dried banana stem biomass was subjected to

pyrolysis at 400ꢀ°C for 1 hr in a muffle furnace. (2).

Chemical Activation: The resulting char was

impregnated with HCl at the designated

This study aims to synthesize HCl-activated

carbon from kepok banana stems, evaluate its

physicochemical properties based on national

standards, and investigate its adsorption

capacity for Fe(III) ions using Freundlich and

Langmuir isotherm models. The outcome is

expected to contribute to the development of

low-cost, sustainable adsorbents for water and

wastewater treatment applications.

concentrations and stirred for

4

hr. (3).

Neutralization and Washing: The activated

carbon was washed with distilled water until

neutral pH was achieved and then oven-dried.

(4). Adsorption Testing: The dried activated

carbon was exposed to 100ꢀppm Fe(II) solution

for 30 min to assess its adsorption performance.

Analytical technique: the physical and chemical

properties of the activated carbon were

evaluated based on the Indonesian National

Standard (SNI 06-3730-1995), including: moisture

content analysis [7], ash content analysis [13],

volatile matter content analysis [14], fixed carbon

content analysis [14], and iodine number

determination. The Fe(II) adsorption capacity was

Materials and Methods

Chemicals

The primary raw material used in this study was

kepok

banana

(Musa

paradisiaca)

stems,

collected from agricultural waste sources, Riau

Province. These stems were thoroughly cleaned,

sun-dried, and processed prior to further

treatment. The equipment utilized included a

mechanical grinder, porcelain crucibles, a muffle

furnace, desiccator, laboratory oven, burettes,

and a 70-mesh sieve. The chemicals employed in

the study were analytical grade and included

hydrochloric acid (HCl) at varying concentrations

(1.5ꢀN, 2.0ꢀN, 3.0ꢀN, 5.0ꢀN, and 7.0ꢀN), 0.1ꢀN iodine

solution, 0.1ꢀN sodium thiosulfate (Na₂S₂O₃), 1%

starch indicator, distilled water, and 100ꢀppm

measured

using

an

Atomic

Absorption

Spectrophotometer (AAS), while the surface

functional groups were characterized using

Fourier Transform Infrared (FTIR) spectroscopy

to identify active sites responsible for adsorption.

Activated Carbon

The preparation of activated carbon from Musa

paradisiaca (kepok banana) stems involved four

main stages: sample preparation, carbonization,

chemical activation, and neutralization. In the

first stage, the banana stems were thoroughly

washed with water to remove adhering soil and

impurities. The cleaned stems were then cut into

small segments to facilitate drying. The segments

Fe(II)

standard

solution

prepared

from

FeSO₄·7H₂O.

Preparation of Samples

The study employed an experimental approach,

incorporating both observational and analytical

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were sun-dried for seven consecutive days to

reduce moisture content, a crucial step to ensure

efficient carbonization. The second stage was

carbonization, wherein the dried biomass was

weighed and subjected to pyrolysis in a muffle

furnace at 400ꢀ°C for 1 hr under limited oxygen

conditions. The resulting biochar was ground

using a mortar and sieved through a 70-mesh

sieve to obtain a uniform particle size. The third

stage was chemical activation. The sieved carbon

was impregnated in hydrochloric acid (HCl) at

various concentrations (0.1, 0.2, 0.5, 0.7, 1.0, 1.5,

2.0, 3.0, 5.0, and 7.0 N). The mixture was stirred

for 4 hr to allow sufficient activation. The final

stage was neutralization, in which the activated

carbon was washed repeatedly with distilled

water until the rinse water reached neutral pH.

The product was then dried in an oven at 110ꢀ°C

until a constant weight was achieved. After

cooling in a desiccator, the activated carbon was

ready for further analysis.

Result and Discussion

Characteristics of Activated Carbon from Kepok

Banana Stems

The physical and chemical characteristics of

activated carbon derived from Kepok banana

(Musa paradisiaca) stems treated with varying

concentrations of hydrochloric acid (HCl) ranging

from 1 N to 7 N are presented in Table 2. The

water content of the samples varied between

2.3392% and 3.5707%. Notably, the lowest

moisture level was observed at a concentration

of 3 N HCl, suggesting more effective drying and

improved stability of the resulting activated

carbon. A lower water content is advantageous

because

excess

moisture

can

obstruct

adsorption sites and diminish overall adsorption

efficiency.

The ash content exhibited a decreasing trend as

the HCl concentration increased up to 3 N, where

it reached a minimum value of 0.2799%. Ash

represents the inorganic residues remaining

after combustion and can negatively impact the

adsorption process by occupying active sites.

Therefore, the reduction in ash content at 3 N

implies more efficient removal of mineral

impurities and an enhancement in the chemical

purity of the activated carbon.

Metal Adsorption

Adsorption performance was evaluated using a

synthetic solution of Fe(II) prepared from

FeSO₄·7H₂O. A total of 5 g of activated carbon

(from each HCl concentration treatment) was

added to 50ꢀmL of 100ꢀppm Fe(II) solution. The

mixture was stirred using a magnetic stirrer at

400ꢀrpm for 30 min to ensure uniform contact.

After the adsorption process, the solution was

filtered, and the filtrate was collected for analysis.

The residual Fe concentration was measured

using an Atomic Absorption Spectrophotometer

(AAS) to determine the adsorption efficiency

Similarly, the volatile matter content showed a

consistent

decline

with

increasing

acid

concentration, achieving the lowest value of

2.0502% at 3 N. Reduced volatile matter is

indicative of a higher degree of carbonization and

contributes to the development of a more stable

and robust carbon structure, which is essential

for maintaining adsorption capacity during

repeated use. The bound carbon content

increased progressively with acid concentration

up to 3 N, attaining a maximum of 95.3307%. This

finding suggests that a 3 N HCl treatment

facilitates the optimal formation of the carbon

matrix, thereby enhancing the structural integrity

and adsorptive performance of the material.

IR-Fingerprint

To identify functional groups on the activated

carbon surface, Fourier Transform Infrared

Spectroscopy (FTIR) analysis was conducted.

Approximately 0.1ꢀmg of dried activated carbon

was finely ground using an agate mortar until

homogeneous. The powder was evenly spread

on the FTIR sample holder, ensuring full surface

coverage. The sample was then scanned to

record its infrared spectrum. Characteristic

absorption peaks were analyzed to identify

functional groups relevant to adsorption, such as

–OH, C=O, C–H, and C=C.

Moreover, the iodine absorbency, which serves

as a key indicator of microporous surface area

and porosity, also peaked at 3 N, recording a

value of 1116.98 mg/g. High iodine numbers

reflect a well-developed microporous network,

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Chempublish Journal, 9(1) 2025,130-140

which is crucial for effective adsorption of small

molecules.

matter, and superior iodine absorbency. These

attributes collectively indicate that 3 N HCl

constitutes the optimal activation condition for

producing high-quality activated carbon from

In summary, the activated carbon produced

using 3 N HCl demonstrated the most favorable

combination of physicochemical properties: high

bound carbon content, minimal ash and volatile

Kepok

banana

stems,

offering

promising

potential for applications requiring efficient

adsorbent materials.

Tabel 2. Characteristic Test Data of Activated Carbon from Kepok Banana Stems

Cons. HCl

(N)

Water

Content (%)

Ash

Content (%)

Volatile

Matter

Content (%)

5.5505

Bound Carbon

Content (%)

Absorbency

Iod (mg/g)

1

1.5

2

3

5

3.5707

3.0194

2.7575

2.3392

2.9094

3.3177

2.3607

0.4103

0.3299

0.2799

0.8695

1.3082

88.118

92.9592

93.384

95.3307

93.3117

91.5064

1002.75

1078.91

1104.29

1116.98

1015.44

951.975

3.6111

3.5286

2.0502

2.9094

7

3.8677

Tabel 3. Data on Iron (Fe) Metal Absorption Results

HCl Concentration

(N)

Initial Concentration

(ppm)

Final Concentration

(ppm)

Adsorbed Fe

Content (%)

1

1.5

2

3

5

1.7619

1.6667

1.0952

0.8571

1.0476

1.4762

98.2373

98.3325

98.9043

99.1425

98.9519

98.5231

99.9524

7

N HCl concentration, the ash content produced

increased to 0.8695%. High ash content can

reduce the adsorption power of activated carbon

on adsorbates because of the many metal oxides

and minerals that spread and cover the pores of

activated carbon. Based on the data obtained

from the ash content test, all activated carbon

products meet the SNI 06-3730-1995 standard,

which is less than 10%.

12

10

8

6

4

2

0

2

4

6

8

HCl Activator Concentration(N)

SNI (%)

Ash Content

The

relationship

between

HCl

activator

Figure 1. Effect of HCl Activator Concentration on

concentration and ash content can be seen in

Figure 2. In Figure 2, it can be seen that the ash

content value decreases with the addition of

activator concentration. Activated carbon that

Water Content

In Figure 1, it can be seen that the ash content

value decreases with the addition of activator

concentration. Activated carbon that has the best

concentration is the 3 N concentration of

0.2799%. The higher the concentration of HCl

activator used, the smaller the ash content. At 5

has the best concentration is the

3

N

concentration of 0.2799%. The higher the

concentration of HCl activator used, the smaller

the ash content. At 5 N HCl concentration, the

resulting ash content increased to 0.8695%. High

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ash content can reduce the adsorption power of

activated carbon on adsorbates due to the large

amount of metal oxides and minerals that spread

and cover the pores of activated carbon. Based

on the data obtained from the ash content test,

all activated carbon products meet the SNI 06-

3730-1995 standard, which is less than 10%.

Bound Carbon Content

120

100

80

60

40

20

0

12

10

8

0

2

4

6

8

HCl Activator Concentration (N)

SNI (%)

Figure 4. Effect of HCl Activator Concentration on

6

Bound Carbon Content

4

2

Based on Figure 4, it can be seen that the

percentage of bound carbon content tends to

increase with each addition of HCl activator,

namely at concentrations of 1.5 ; 2 and 3 N. The

increase in percentage is influenced by the low

value of moisture content, ash content, and

volatile substance content of activated carbon.

Based on the bound carbon content of all

samples, it has met the quality standards of

activated carbon, which is at least 65% with

concentrations of 1.5 ; 2 ; 3 ; 5 N and 7 N because

the banana stem carbonization time is almost

perfect and the carbonization temperature is set

according to the condition of the banana stem as

raw material.

0

2

4

6

8

HCl Activator Concentration (N)

SNI (%)

Figure 2. Effect of HCl Activator Concentration on

Ash Content

Volatile Matter Content Test. The relationship

between HCl activator concentration and

moisture content can be seen in Figure 3.

30

20

10

0

Iodine Absorbency. The relationship between HCl

activator concentration and iodine absorbance

can be seen in Figure 5.

0

2

4

6

8

HCl Activator Concentration (N)

SNI

1200

1000

800

600

400

200

0

Figure 3. Effect of HCl Activator Concentration on

Volatile Matter Content

Figure 3 shows that the volatile matter content

decreased

with

increasing

HCl

activator

concentration. The vaporized substance content

decreased from 0.1 N concentration to 3 N

concentration. The lowest vaporized substance

content at 3 N activator concentration was

2.0502%. The level of vaporized substances

increased at a concentration of 5 N, which

amounted to 2.9094%. The increase in ash

content occurs because of the many metal oxides

and minerals that spread and cover the pores of

activated carbon. The volatile matter content of

all samples has met the SNI 06-3730-1995

standard, which is no more than 25%.

0

2

4

6

8

HCl Activator Concentration (N)

SNI (mg/g)

Figure 5. Effect of HCl Activator Concentration

on Iodine Absorbency

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Chempublish Journal, 9(1) 2025,130-140

The percentage of iodine absorption increased

with each addition of HCl concentration, namely

1.5; 2 and 3 N concentrations, but decreased at 5

N and 7 N HCl concentrations. This is because the

(0.8571 ppm) and highest Fe removal efficiency

(99.1425%) occurred with activated carbon

treated at 3 N HCl, again highlighting its superior

performance.

All treatments achieved

Fe

higher

the

addition

of

the

activator

adsorption efficiencies above 98%, indicating

that even non-optimized activated carbon

exhibits strong Fe adsorption capacity.

concentration, the greater the effect of the

activator in binding the residual compounds to

exit through the charcoal micro pores, so that

there is a decrease with too high a concentration

of NaOH which results in too fast a mass transfer

of the activator binding the remaining tar to exit

the charcoal micro pores so that the remnants of

tar collect on the surface of the charcoal micro

pores, as a result the adsorption power of

activated charcoal decreases [17]. Based on all

the iodine absorption sample data, all samples

meet the SNI 06-3730-1995 standard, which is a

minimum of 750 mg/g.

Adsorption efficiency increased with acid

concentration up to

3

N, consistent with

improvements in iodine number and carbon

content. Beyond 3 N (e.g., 5 N and 7 N),

performance declined slightly, likely due to pore

collapse or over-etching, which can reduce

effective surface area. There is a clear correlation

between bound carbon content, iodine number,

and Fe adsorption efficiency. Higher bound

carbon and iodine numbers reflect more

developed porous structures, enabling more

effective trapping of metal ions.

Iron (Fe) Metal Absorption Efficiency

Table 3 presents the data on Fe(III) adsorption

from solution using the produced activated

carbon. Initial Fe concentration was 99.9524 ppm

across all tests. The lowest final Fe concentration

The consistent peak performance at 3 N HCl

across both tables suggests this concentration

yields optimal textural and chemical properties

for metal adsorption applications.

Figure 8. Graphic Isoterm Freundlich Fe

is seen in the Freundlich isotherm graph, this

proves that the adsorption isotherm in the

research of making activated carbon from kepok

banana stems follows the Freundlich isotherm

model. The n value describes the adsorption

Isoterm Adsorption

From Figures 8 and 9, it can be seen that the

regression value that shows a number close to 1

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Chempublish Journal, 9(1) 2025,130-140

process, where

n

<

1

indicates chemical

in the adsorption process, the smaller the 1/n

value, the stronger the interaction between the

adsorbent and the adsorbate [19-20].

adsorption, n = 1 indicates linear adsorption, and

n > 1 indicates physical adsorption [17]. The 1/n

value is a function of the strength of adsorption

Figure 9. Graphic Isoterm Langmuir Fe

determine the chemical components of activated

carbon in the form of functional groups and

active groups of activated carbon. The resulting

infrared spectra are as in Figure 10.

IR In this study, the adsorbent of activated kepok

banana stem carbon was identified using FTIR

(Fourier

Transform

Infrared

Spectroscopy)

(Genesys 20 Visible Spectrophotometer, USA) to

Figure 10. IR Fingerprint activated carbon

From the test sample, bread of kapok banana

after being activated, the FTIR spectrum shows

distinct peaks indicating the presence of various

functional groups. The activated carbon displays

a high-intensity peak at 3236.08 cm⁻¹, which

corresponds to O-H stretching vibrations,

typically from hydroxyl groups found in alcohols

or phenols. This indicates surface oxidation and

functionalization, which commonly occurs during

the activation process [21-23].

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In comparison, non-activated carbon generally

shows much weaker or broader O-H stretching

bands due to the limited surface functional

groups and lower porosity. The emergence of a

sharp O-H band in activated samples confirms

enhanced surface chemistry, favorable for

adsorptive interactions [24-26].

generally

enhances

the

physicochemical

properties of the activated carbon; however,

concentrations exceeding the optimal level may

lead to a decline in adsorption capacity due to the

saturation of the carbon matrix, which inhibits

further

condition was achieved at

concentration, resulting in

effective

activation.

The

optimal

HCl

maximum Fe

a

3

N

a

Furthermore, absorptions at 1373, 1308, 523,

429, 418, and 406 cm⁻¹ correspond to C-H

bending vibrations of alkanes. These bands are

adsorption efficiency of 99.14%. The adsorption

data also followed the Freundlich isotherm

model more accurately than the Langmuir

model, as evidenced by a higher regression

coefficient (R² = 0.9921 for Freundlich compared

more

pronounced

in

activated

of

carbon,

complex

suggesting

the breakdown

lignocellulosic structures and exposure of

aliphatic chains after thermal and chemical

treatment. In non-activated carbon, such peaks

are typically subdued due to the presence of

to

0.9667

for

Langmuir),

surface and

indicating

a

heterogeneous

multilayer

adsorption process. Furthermore, the activated

carbon produced under these conditions met the

requirements of the Indonesian National

Standard (SNI), with a moisture content of 2.34%,

ash content of 0.23%, volatile matter content of

2.05%, bound carbon content of 95.33%, and an

iodine adsorption capacity of 1116.98 mg/g,

confirming its high quality and applicability for

metal ion adsorption in water treatment.

intact

macromolecular

lignin-cellulose

structures.

A prominent peak at 1567.12 cm⁻¹ and 1588.44

cm⁻¹ indicates C=C aromatic stretching,

highlighting the presence of condensed aromatic

structures formed during carbonization. These

peaks are either absent or poorly defined in non-

activated samples, as the aromatic domains are

less developed before pyrolysis and activation

[26].

Acknowledgement

The authors are thankfull to Politeknik Negeri

Sriwijaya,

which

has

facilitated

the

implementation of this research.

Additionally, the peak at 1083.28 cm⁻¹ is

attributed to C–O stretching, characteristic of

alcohols, ethers, or carboxylic acid groups, often

enhanced after activation with agents like HCl or

H₃PO₄. Such functional groups are valuable for

binding polar adsorbates. The corresponding

peaks at 446 and 418 cm⁻¹ also reinforce the

presence of C-H bonds in alkane structures. The

Author Contributions

Conceptualization, IS, FNA; Methodology, IS ;

Software, ES ; Validation, ES ; Formal Analysis,

ASN ; Investigation, ASN ; Resources, FNA ; Data

Curation, FNA

;

Writing

–

Original Draft

Preparation, FNA ; Writing – Review & Editing,

SMN ; Visualization, SMN ; Supervision, FNA ;

comparison

between

non-activated

and

activated carbon FTIR spectra clearly shows that

activation significantly enhances the surface

functionality of kapok banana-derived carbon.

The activated sample is enriched in hydroxyl,

aromatic, alkane, and ether/carboxyl groups, all

of which contribute to its adsorptive efficiency.

Project

Administration,

FNA

;

Funding

Acquisition, FNA.

Conflict of Interest

The authors declare no conflict of interest.

Conclusion

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Characterization

of

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Chempublish Journal, 9(1) 2025,130-140

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Solid

Materials

[Indonesian

National

291

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