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"Nanokomposit berbasis biopolimer yang mengalami adsorpsi ion logam pada permukaan bahan pendukung magnetik memiliki kemampuan katalitik lebih baik sehingga menarik untuk dikembangkan sebagai katalis dalam reaksi reduksi 4-nitrofenol. Nanokomposit NaAlg-CMC/Fe3O4 dan NaAlg-CMC/Fe3O4-Cu telah berhasil disintesis yang didukung dengan karakterisasi menggunakan FTIR, XRD dan SEM-EDS Mapping. NaAlg-CMC merupakan biopolimer yang bertindak sebagai support katalis dan dapat membentuk komposit dengan sifat yang baik saat digabungkan dengan Fe3O4. Nanokomposit NaAlg-CMC/Fe3O4 dapat digunakan sebagai adsorben yang baik dalam penghilangan ion Cu2+. Kondisi optimum diperoleh pada berat nanokomposit 50 mg, pH 5,5, rasio NaAlg-CMC/Fe3O4 2:1, waktu kontak 90 menit dengan persen penghilang 97,80% dan kapasitas adsorpsi 48,9018 mg/g. Isoterm adsorpsi ion Cu2+ mengikuti model isoterm adsorpsi Langmuir dengan R2 sebesar 0,9944. Nanokomposit NaAlg-CMC/Fe3O4-Cu dapat menjadi katalis yang baik dalam reduksi katalitik 4-nitrofenol dengan persen reduksi sebesar 92,95 pada berat katalis 45 mg dan waktu reaksi 11 menit. Studi kinetika reaksi reduksi 4-nitrofenol menjadi 4-aminofenol mengikuti kinetika reaksi orde pertama dengan persamaan v = 0,2592 menit-1 [4-NP]. Nanokomposit yang diperoleh dapat menjadi solusi untuk mengurangi logam berat dan polutan organik yang ramah lingkungan.

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Biopolymer-based nanocomposite with adsorbed metal ions on the surface of magnetic support has better catalytic ability that is interest to be developed as a catalyst in the reduction of 4-nitrofenol. SA-CMC/Fe3O4 and SA-CMC/Fe3O4-Cu have been successfully synthesized and supported by characterization using FTIR, XRD and SEM-EDS Mapping. SA-CMC is a biopolymer-based composite as a supporting catalyst and able to form composites with good properties when combined with Fe3O4. SA-CMC/Fe3O4 nanocomposites can be used as good adsorbents of Cu2+ in wastewater. The optimum conditions were obtained by the adsorbent dosage 50 mg, pH 5.5, ratio of SA-CMC/Fe3O4 2:1, contact time 90 minutes with efficiency removal 97.80% and maximum adsorption capacity reached 48,9018 mg/g. The adsorption process of Cu2+ removal follows the Langmuir adsorption isotherm model. SA-CMC/Fe3O4-Cu nanocomposite can be a good catalyst in the reduction of 4-nitrophenol with percent of reduction 92.95% by amount of catalyst 45 mg and reaction time 11 minutes. Study kinetics of reduction 4-nitrophenol to 4-aminophenol follows pseudo-first-order reactions with equation v = 0,2592 min-1 [4-NP]. Nanocomposite can remove heavy metal and organic pollutant in wastewater that are environmentally friendly."

"The adsorption properties of surface-modified mesoporous silica materials containing ?-cyclodextrin (CD ICS) were studied using two types of gas phase adsorbates (N2 and CH3Cl), along with a dye molecule (p-nitrophenol; PNP) in an aqueous solution. The CD ICS materials possess an ordered silica mesostructure framework that depends on the type of surfactant template and the level of loading of ?-CD. Incremental variations in the uptake of gas phase adsorbates and PNP from an aqueous solution were observed, according to the composition of CD ICS materials. For materials with similar CD loading, the surface area (SA) and pore volume doubled, as the surfactant from dodecylamine to hexadecylamine was varied. The SA of the CD ICS materials decreased by ca. 1.5-fold as the CD loading varied from 2% to 6%. The sorption capacity (Qe; mmol/g) of PNP increased from 61% to 84% as the CD loading increased from 2% to 6% and as the alkyl chain length of the surfactant template varied from C12 to C16. The adsorption properties of CD ICS materials with CH3Cl in the gas phase and for PNP in aqueous solution adopt a multi-layer adsorption profile, as described by the BET isotherm model."

"Dengan pertumbuhan industrialisasi yang masif di era ini, fenomena pelepasaan zatzat polutan berbahaya ke lingkungan mengalami peningkatan yang cukup pesat. Salah satu zat polutan yang banyak digunakan di berbagai sektor industri adalah 4-nitrofenol. Pelepasan 4-nitrofenol dari berbagai aktivitas industri dapat dengan mudah mengontaminasi sumber air dan ekosistem, yang kemudian masuk ke dalam tubuh manusia dan menyebabkan berbagai isu kesehatan. Salah satu metode penanganan 4- nitrofenol yang efektif adalah melalui mekanisme reduksi dengan NaBH4, dan salah satu jenis katalis yang menarik perhatian untuk digunakan pada proses ini karena kemampuan transfer elektronnya yang baik adalah NiFe2O4. Pada percobaan ini, dilakukan sintesis NiFe2O4 mesopori terdekorasi logam Cu sebagai katalis untuk reaksi reduksi 4-nitrofenol. NiFe2O4 mesopori disintesis dengan menggunakan SBA-15 sebagai hard template dan melalui metode nanocasting. SBA-15 kemudian dihilangkan dari NiFe2O4 sebelum dilakukan tahap dekorasi. Dekorasi Cu dilakukan dengan penambahan prekursor Cu ke NiFe2O4 yang kemudian direduksi dengan menggunakan NaBH4. Hasil sintesis kemudian dikarakterisasi dengan FTIR, XRD, XRF, TEM, dan BET. Hasil karakterisasi menunjukkan keberhasilan sintesis material. Akitvitas katalitik diuji pada reaksi reduksi 4-nitrofenol. Cu terbukti memiliki pengaruh positif terhadap aktivitas NiFe2O4. Model kinetika orde pseudo-satu menunjukkan dalam 16 menit NiFe2O4 memiliki nilai konstanta laju 0,004 min-1 dengan %reduksi sebesar 6,35%. Sementara itu, Cu/NiFe2O4 (0,125) memperoleh nilai persentase reduksi sebesar 34,549% dalam 16 menit dengan konstanta laju k = 0,028 min-1 , dan Cu/NiFe2O4 (0,25) sebesar 98,68% dengan nilai k = 0,213 min-1 . Cu/NiFe2O4 (0,5) menunjukkan aktivitas yang jauh lebih baik, yaitu %reduksi 100% dalam interval waktu hanya 40 detik. Hal ini menunjukkan makin banyak jumlah Cu di dalam komposit, aktivitas katalitik terhadap reaksi reduksi 4-nitrofenol makin baik.

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With the massive growth of industrialization in this era, the phenomenon of releasing harmful pollutants into the environment has increased rapidly. One of the pollutant substances that are widely used in various industrial sectors is 4-nitrophenol. The release of 4-nitrophenol from various industrial activities can easily contaminate water sources and ecosystems, which then enter the human body and cause various health issues. One of the effective methods of handling 4-nitrophenol is through the reduction mechanism with NaBH4, and one type of catalyst that attracts attention to be used in this process because of its good electron transfer ability is NiFe2O4. In this experiment, Cu metal-decorated mesoporous NiFe2O4 was synthesized as a catalyst for the reduction reaction of 4-nitrophenol. Mesoporous NiFe2O4 was synthesized by using an SBA-15 as hard template and through nanocasting method. SBA-15 was then removed from NiFe2O4 before the decoration stage. Cu decoration was carried out by the addition of Cu precursor to NiFe2O4 which was then reduced using NaBH4. The synthesis results were then characterized by FTIR, XRD, XRF, TEM, and BET. The characterization results showed the success of the material synthesis. The catalytic activity was tested on the reduction reaction of 4-nitrophenol. Cu was shown to have a positive influence on the activity of NiFe2O4. The pseudo-first-order kinetics model shows that in 16 min NiFe2O4 has a rate constant value of 0.004 min-1 with a %reduction of 6.35%. Meanwhile, Cu/NiFe2O4 (0.125) obtained a percentage reduction value of 34.549% in 16 min with a rate constant of k = 0.028 min-1, and Cu/NiFe2O4 (0.25) of 98.68% with a value of k = 0.213 min-1. Cu/NiFe2O4 (0.5) showed much better activity, i.e. 100% reduction % in a time interval of only 40 seconds. This shows that the greater the amount of Cu in the composite, the better the catalytic activity towards the reduction reaction of 4-nitrophenol."