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Abstrak :
Nanokomposit BiFeO3/LaFeO3 dan BiFeO3/LaFeO3/Graphene dengan variasi persen berat (wt.%) graphene sebanyak 3, 5, dan 10 wt.% telah berhasil difabrikasi menggunakan metode berbantuan ultrasonik. Tidak adanya pengotor dan fasa lain pada nanokomposit ditunjukkan dari hasil karakterisasi X-ray Diffraction (XRD) dan X-ray Fluorescence (XRF). Keberadaan material graphene dan interaksinya dengan nanokomposit BiFeO3/LaFeO3 yang tidak terdeteksi oleh pengukuran XRD dan XRF dapat dilihat dengan jelas melalui pengukuran X-ray Photoelectron Spectroscopy (XPS), Thermogravimetric Analysis (TGA), dan Raman Spectroscopy. Pengukuran UV-Vis Diffuse Reflectance Spectroscopy (UV-Vis DRS) menunjukkan bahwa energi celah pita berkurang karena adanya material graphene. Kehadiran grafena sangat terlihat pengaruhnya pada hasil pengukuran isoterm adsorpsi-desorpsi N2 yang ditandai dengan peningkatan luas permukaan yang drastis dan perubahan bentuk pori-pori permukaan. Nanokomposit BiFeO3/LaFeO3/Graphene menunjukkan aktivitas fotokatalitik yang lebih unggul dibandingkan dengan BiFeO3, LaFeO3, dan BiFeO3/LaFeO3 pada paparan cahaya tampak. Uji reusability menunjukkan stabilitas nanokomposit pada penggunaan berulang sebanyak 4 kali. ......BiFeO3/LaFeO3 and BiFeO3/LaFeO3/Graphene nanocomposites with variations in weight percent (wt.%) graphene as much as 3, 5, and 10 wt.% have been successfully fabricated using ultrasonic-assisted methods. The absence of impurities and other phases in the nanocomposite was shown from the results of X-ray Diffraction (XRD) and X-ray Fluorescence (XRF) characterization. The presence of graphene material and its interactions with BiFeO3/LaFeO3 nanocomposites that were not detected by XRD and XRF measurements could be clearly seen through X-ray Photoelectron Spectroscopy (XPS), Thermogravimetric Analysis (TGA), and Raman Spectroscopy measurements. Measurement of UV-Vis Diffuse Reflectance Spectroscopy (UV-Vis DRS) showed that the band gap energy was reduced due to the presence of graphene material. The presence of graphene has a very visible effect on the measurement results of the N2 adsorption-desorption isotherm which is characterized by a drastic increase in surface area and a change in the shape of the surface pores. BiFeO3/LaFeO3/Graphene nanocomposite showed superior photocatalytic activity compared to BiFeO3, LaFeO3, and BiFeO3/LaFeO3 on exposure to visible light. The reusability test showed the stability of the nanocomposite on repeated use 4 times.

Abstrak :
Pada penelitian ini dilakukan fotodegradasi metilen biru dengan menggunakan katalis berbagai morfologi TiO2 (TiO2 nanocube dan TiO2 nanospindel) yang diintegrasikan dengan nanopartikel Au. Pengujian aktivitas fotokatalitik untuk degradasi metilen biru dilakukan dengan menggunakan sinar tampak. Hasil karakterisasi XRD membuktikan bahwa nanopartikel TiO2 nanocube dan TiO2 nanospindel memiliki struktur kristal tetragonal. Aktivitas fotokatalitik nanopartikel TiO2 mengalami peningkatan karena dapat aktif pada daerah sinar tampak setelah diintegrasikan dengan nanopartikel emas, didukung melalui hasil karakterisasi UV-Vis DRS yaitu nilai energi band gap pada kedua Au-TiO2 nanohybrids sebesar 3.3 eV. Studi aktivitas fotokatalitik TiO2 nanocube, TiO2 nanospindel dan Au-TiO2 nanohybrids diamati dengan reaksi degradasi metilen biru dibawah sinar tampak. Persentase degradasi pada konsentrasi 0.01 mM TiO2 nanocube yaitu 27,11%, TiO2 nanospindel sebesar 35,59 %, pada Au-TiO2 nanocube yaitu 40 %, dan Au-TiO2 nanospindel 55,67 % selama 1 jam waktu penyinaran. Perhitungan kinetika reaksi fotodegradasi metilen biru didapatkan bahwa Au-TiO2 nanohybrids mengikuti kinetika orde satu. ......In this study photodegradation of methylene blue using Au-TiO2 nanohybrids, TiO2 nanocube, TiO2 nanospindel as catalyst. Photocatalytic activity test for degradation of methylene blue using visible light. Characterization with XRD proves TiO2 nanocube and TiO2 nanospindle have a tetragonal structure, Photocatalytic activity of TiO2 nanoparticles can be active in visible light radiation after it modified by Au nanoparticles, UV-Vis DRS has proven that nanohybrids have band gap energy of 3.3 eV. The study of photocatalytic activity TiO2 nanocube, TiO2 nanospindle, and nanohybrids Au-TiO2 were observed with methylene blue degradation using visible light radiation. Percentages of degradation at the concentration of 0,01 mM. TiO2 nanocube is 27,11%, TiO2 nanospindle is 35,59%, nanohybrids Au-TiO2 nanocube is 40% and nanohybrids Au-TiO2 spindle is 55,67% for 1 hour irradiation time.  In study of reaction kinetics shows that degradation of methylene blue followed the pseudo-first order kinetics.

Abstrak :
Kebutuhan air bersih meningkat seiring dengan bertambahnya populasi penduduk, namun kebutuhan air bersih tercemar karena kontaminasi limbah cair salah satunya akibat zat warna, proses degradasi zat warna sangat perlu dilakukan dalam upaya reduksi pencemaran air, Salah satu metode yang dapat dilakukan adalah fotodegradasi. Pada penelitian ini dilakukan fotodegradasi zat warna Methylene Blue melalui proses fotokatalitik dengan nanokatalis heterostruktur Au-TiO2. Sintesis TiO2 Nanosheet yang melalui metode Hidrotermal, didapatkan nilai celah pita sekitar 3.38 eV untuk struktur Anatase dengan panjang rata-rata 28 nm dan ketebalan 3.05 nm. Au Nanorod disintesis melalui metode Seeds Mediated Growth dengan variasi penambahan AgNO3 menghasilkan profil fenomena resonansi permukaan plasmon (SPR) yang berbeda dengan serapan paling tinggi pada 800 nm dan aspect ratio yang meningkat dari 3.7-4.5. Integrasi dilakukan dengan metode Ligand Exchange dan pengaturan pH. Laju kinetika tertinggi dari hasil fotodegradasi dicapai oleh Au-TiO2 yang diintegrasi melalui metode Ligand Exchange sebesar 0.1029 min-1. ...... Demand of clean water increase along with an increase in population, but the presence of organic dyes has become one of the reasons of water contaminant and becoming an environmental problem, the treatment of dye removal nowadays is become very necessary to reduce water pollution. The most efficient and reliable method to degraded organic dyes is using photodegradation method. In this research, we report the result of Methylene Blue photodegradation through the photocatalytic process using Au-TiO2 heterostructured nanocatalysts. TiO2 nanosheets was synthesized through hydrothermal method, the band gap value is 3.38 eV for Anatase structures with an average length of 28 nm and thickness of 3.05 nm. Gold nanorods was synthesized through Seeds Mediated Growth method with variations in the addition of AgNO3. Show a different profile of the Surface Plasmon Resonance (SPR) phenomenon with the highest absorption at 800 nm and an increased aspect ratio from 3.7-4.5. Integration of Au-TiO2 was done by the Ligand Exchange Method and pH control. The high kinetic rate was achieved from Au-TiO2 nanocatalyst done by the Ligand Exchange Method with 0.1029 min-1.

Abstrak :
Pada studi ini, saya menggunakan metode fotokatalitik untuk mendegradasi limbah cat pewarna organik dalam limbah air menggunakan MgFe2O4 dan MgFe2O4-nanographene (MgFe2O4/NGP) nanopartikel. MgFe2O4 dan MgFe2O4/NGP (mengandung persentase NGP yang bervariasi) disintesis melalui metode hidrotermal. Kedua bahan ini digunakan sebagai katalis dalam proses fotokatalitik mendegradasi limbah organic Methylene-Blue dalam solusi cair, dibawah radiasi cahaya merah. Karakteristik dari sample (MgFe2O4 & MgFe2O4/NGP) dilakukan menggunakan X-ray Diffraction, Raman Spectroscopy, UVVIS Spectroscopy, XRF, TGA, BJH, XPS, TEM, HRTEM, SAED, EDX dan BET. Hasil dari penelitian ini menunjukkan bahwa MgFe2O4/NGP mempunyai kemampuan fotokatalitik yang lebih baik dibandingkan dengan MgFe2O4. Efek dari konsentrasi NGP (wt%) untuk mendegradasi MB didiskusikan. Spesies aktif dalam proses fotokatalitik juga dipelajari melalui scavenger test.

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In the current study, we use the photodegradation method for the removal of organic dye molecule in wastewater using MgFe2O4 and MgFe2O4-nanographene platelets (MgFe2O4/NGP) nanoparticles. MgFe2O4 and MgFe2O4/NGP (containing various amounts of NGP) were synthesized using the hydrothermal method. Both of them used as a catalyst for photocatalytic degradation of methylene blue (MB), i.e. our organic dye in aqueous solution under red light irradiation. Characteristics of our samples (MgFe2O4 & MgFe2O4/NGP) were characterized using X-ray diffraction, Raman Spectroscopy, UVVIS Spectroscopy, XRF, TGA, BJH, XPS, TEM, HRTEM, SAED, EDX, and BET. The result of our work showed that MgFe2O4/NGP mostly have a better photocatalytic performance compared to pure MgFe2O4. The effect of NGP concentration (wt%) on the photocatalytic degradation of MB was discussed. Active species who'd take effect on the photocatalytic process was also studied by the scavenger test.

Abstrak :
The main problem with the slurry process is the difficulty in recovering the photocatalyst nanoparticle from water following purification. An alternative solution proposed the photocatalyst be immobilized on magnetic carriers, which would allow them to be recollected from the water suspension following treatment using an external magnetic field. Magnetically photocatalyst composites were prepared using simple heteroagglomeration by applying attractive electrostatic forces between the nanoparticles with an opposite surface charge. The Fe3O4/SiO2/TiO2 photocatalysts were synthesized in an aqueous slurry solution containing Fe3O4/SiO2 and TiO2 nanoparticles under pH 5 conditions. Meanwhile, Fe3O4/SiO2 was prepared by a simple procedure via a coprecipitation of iron(II) and iron(III) ion mixtures in ammonium hydroxide and was leached by sodium silicate. The synthesized samples were investigated to determine the phase structure, the magnetic properties, and the morphology of the composites by X-ray diffraction (XRD), vibrating sample magnetometer (VSM), and transmission electron microscopy (TEM), respectively. The results indicated that the composites contained anatase and rutile phases and exhibited a superparamagnetic behavior. Fe3O4/SiO2 particles, which were of the aggregation spherical form at 20 nm in size, were successfully attached onto the TiO2 surface. The catalytic activity of Fe3O4/SiO2/TiO2 composites was evaluated for the degradation of methylene blue under ultraviolet (UV) irradiation. The presence of SiO2 as a barrier between Fe3O4 and TiO2 is not only improves the photocatalytic properties but also provides the ability to adsorb the properties on the composite. The Fe3O4/SiO2/TiO2 (50% containing TiO2 in composite) were able to eliminate 87.3% of methylene blue in water through the adsorption and photocatalytic processes. This result is slightly below pure TiO2, which is able to degrade 96% of methylene blue. The resulting Fe3O4/SiO2/TiO2 composite exhibited an excellent ability to remove dye from water and it is easily recollected using a magnetic bar from the water. Therefore, they have high potency as an efficient and simple implementation for the dye effluent decolorization of textile waste in slurry reactor processes.

Abstrak :
The main problem with the slurry process is the difficulty in recovering the photocatalyst nanoparticle from water following purification. An alternative solution proposed the photocatalyst be immobilized on magnetic carriers, which would allow them to be recollected from the water suspension following treatment using an external magnetic field. Magnetically photocatalyst composites were prepared using simple heteroagglomeration by applying attractive electrostatic forces between the nanoparticles with an opposite surface charge. The Fe3O4/SiO2/TiO2 photocatalysts were synthesized in an aqueous slurry solution containing Fe3O4/SiO2 and TiO2 nanoparticles under pH 5 conditions. Meanwhile, Fe3O4/SiO2 was prepared by a simple procedure via a coprecipitation of iron(II) and iron(III) ion mixtures in ammonium hydroxide and was leached by sodium silicate. The synthesized samples were investigated to determine the phase structure, the magnetic properties, and the morphology of the composites by X-ray diffraction (XRD), vibrating sample magnetometer (VSM), and transmission electron microscopy (TEM), respectively. The results indicated that the composites contained anatase and rutile phases and exhibited a superparamagnetic behavior. Fe3O4/SiO2 particles, which were of the aggregation spherical form at 20 nm in size, were successfully attached onto the TiO2 surface. The catalytic activity of Fe3O4/SiO2/TiO2 composites was evaluated for the degradation of methylene blue under ultraviolet (UV) irradiation. The presence of SiO2 as a barrier between Fe3O4 and TiO2 is not only improves the photocatalytic properties but also provides the ability to adsorb the properties on the composite. The Fe3O4/SiO2/TiO2 (50% containing TiO2 in composite) were able to eliminate 87.3% of methylene blue in water through the adsorption and photocatalytic processes. This result is slightly below pure TiO2, which is able to degrade 96% of methylene blue. The resulting Fe3O4/SiO2/TiO2 composite exhibited an excellent ability to remove dye from water and it is easily recollected using a magnetic bar from the water. Therefore, they have high potency as an efficient and simple implementation for the dye effluent decolorization of textile waste in slurry reactor processes.

Abstrak :
Penggabungan teknologi fotokatalisis dan surfaktan yang menggunakan titania dan coconut oil-based primary alkyl sulphate (cocoPAS) untuk mengangkat dan mendegradasi kotoran berupa methylene blue dari pakaian serta menghasilkan limbah dengan konsentrasi cocoPAS yang minimal telah diamati. Penelitian berupa pemvariasian perbandingan konsentrasi cocoPAS dan titania dan juga variasi pH dengan menggunakan jeruk nipis. Kinerja deterjen 0,1%cocoPAS-0,1%titania pada pH 3,6 (penambahan 2,5% jeruk nipis) adalah yang paling efektif, yaitu dapat mengangkat methylene blue dari pakaian 84,31 ppm dari 85,16 ppm atau degradasi methylen blue 99% (1,03 kali lebih baik daripada pH 6,4) dan konsentrasi cocoPAS yang tersisa 2,43 ppm dari 90,88 ppm atau degradasi cocoPAS 97,30% (1,05 kali lebih baik daripada pH 6,4) di bawah sinar UV selama 30 menit. ...... Combination of photocatalytic technology and surfactant that used titania and coconut oil-based primary alkyl sulphate (cocoPAS) to remove and degradate methylene blue as dirt and resulting clean waste with minimal concentration of cocoPAS had been investigate. Research method vary cocoPAS and titania concentration and vary pH by vary concentration of lime. Performance of 0,1%cocoPAS-0,1%titania detergent in pH 3,6 (2,5% lime addition) is the most optimum that can remove 84,31 ppm methylene blue from clothes from 85,16 ppm at first or can degredate 99% metylene blue (1,03 times better than in pH 6,4) and concentraton of cocoPAS is remained 2,43 ppm from 90,88 ppm or can degredate 97,30% cocoPAS (1,05 times better than in pH 6,4) under 30 minutes illumination of UV light.

Abstrak :
Nanopartikel oksida seng (ZnO) yang diberi dopan kromium (Cr) dan penambahan 10 % montmorillonite (MMT) disintesis dengan metode kopresipitasi untuk empat variasi persen atom Cr. Nanopartikel dikarakterisasi menggunakan X-Ray Diffraction (XRD), Energy Dispersive X-Ray (EDX), Fourier Transform Infrared (FTIR), UV-Visible Diffuse Reflectance (UV-Vis) dan Electronic Spin Resonance (ESR). Pengujian aktivitas fotokatalitik dilakukan menggunakan model polutan methylene blue dengan paparan sinar UV. Penambahan montmorillonite dan dopan Cr pada ZnO dapat meningkatkan degradasi methylene blue dengan Cr doped ZnO/MMT 10 at.% menunjukkan degradasi maksimum dengan kondisi optimum dosis fotokatalis 0.7 g/L dan konsenstrasi larutan 20 mg/L. Spesies dominan pada aktivitas fotokatalitik adalah hole dan OH● berturut-turut. ......Chromium (Cr) doped zinc oxide (ZnO) nanoparticles with 10% montmorillonite (MMT) addition were synthesized by co-precipitation method for four chrome atomic percentage variations. Samples were characterized by X-Ray Diffraction (XRD), Energy Dispersive X-Ray (EDX), Fourier Transform Infrared (FTIR), UV-Visible Diffuse Reflectance (UV-Vis) and Electronic Spin Resonance (ESR). Photocatalytic were evaluated using methylene blue under UV light irradiation. MMT addition and Cr dopant to ZnO nanoparticles enhance methylene blue degradation with the optimum conditions are 0.7 g/L of nanoparticle and 20 mg/L of methylene blue initial concentration. Hole and OH● were identified as dominant species of photocatalytic activity.

Abstrak :
ABSTRAK
Penelitian ini ditujukan untuk menghasilkan karbon aktif berbahan dasar kulit durian untuk pengaplikasiannya dalam mengadsorpsi pewarna Methylene Blue. Pada penelitian ini H3PO4 dipakai sebagai aktivator dengan variasi rasio impregnasi 1/1, 2/1, dan 3/1. Aktivasi dilakukan pada suhu 600oC selama 1 jam. Kulit durian dicuci dan dikeringkan menggunakan oven pada suhu 150oC selama 5 jam. Uji bilangan iodin terhadap sampel hasil penelitian menunjukkan bahwa karbon aktif dengan rasio impregnasi 2/1 memiliki daya serap iodin terbesar, yaitu 454.5 mg/g namun karbon aktif rasio 3/1 memiliki %removal terhadap Methylene Blue yang paling besar. Karbon aktif dari kulit durian dengan rasio impregnasi 1/1, 2/1, dan 3/1 secara berturut-turut memiliki %removal sebesar 5.25%, 80.3%, dan 90.35%. Adsorpsi pewarna Methylene Blue oleh karbon aktif kulit durian ini dilakukan dengan variasi rasio impregnasi, massa karbon aktif, konsentrasi awal Methylene Blue, dan waktu kontak

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ABSTRACT
This research aimed to produce durian shell-based activated carbon for its application in the adsorption of Methylene Blue. In this research, H3PO4 was used as an activator with a variety of impregnation ratio which are, 1/1, 2/1, and 3/1. Activation was done at a temperature of 600oC for 1 hour. Durian shell was washed and dried using an oven at 150oC for 5 hours. Iodine number showed that the active carbon with impregnation ratio of 2/1 has the highest number which is 454.5 mg/g, but the activated carbon with impregnation ratio of 3/1 has the biggest % removal of the Methylene Blue dye. Activated carbon from durian shell with impregnation ratio of 1/1, 2/1, and 3/1 respectively have % removal of 5.25%, 80.3% and 90.35%. Methylene Blue dye adsorption by durian shell-based activated carbon was done by varying the impregnation ratio, the mass of activated carbon, the initial concentration of Methylene Blue, and the contact time.

Abstrak :
Nanokomposit ZnO/CuO dengan lima variasi molar ZnO:CuO (1:3, 1:1, 1:0.5, 1:0.3, dan 1:0.1) telah disintesis dengan menggunakan metode sol-gel. Pengukuran X-ray Diffraction (XRD), Energy Dispersive X-Ray (EDX), Field Emission Scanning Electron Microscopy (FESEM), nitrogen adsorption spectroscopy, Electron Spin Resonance (ESR), dan UV-Visible spectroscopy dilakukan untuk mengindentifikasi struktur, morfologi, luas permukaan, resonansi ion-ion, dan nilai celah energi dari nanokomposit. Aktivitas katalitik dari nanokomposit ZnO/CuO diuji dibawah pemaparan cahaya visible, ultraviolet, ultrasonik, dan gabungan antara visible/UV dengan ultrasonik dalam mendegradasi larutan pewarna methylene blue (MB). Hasil aktivitas katalitik dari nanokomposit ZnO/CuO menunjukkan aktivitas photosonocatalytic mempunyai performa lebih baik dibandingkan aktivitas photocatalytic dan sonocatalytic. Penambahan beberapa scavenger menunjukkan hole merupakan spesies aktif yang berperan paling penting dalam mekanisme katalitik.

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ZnO/CuO nanocomposites with five different ZnO:CuO ratios (1:3, 1:1, 1:0.5, 1:0.3 and 1:0.1) were prepared using sol-gel method. X-ray Diffraction (XRD), Energy Dispersive X-Ray (EDX), Field Emission Scanning Electron Microscopy (FESEM), nitrogen adsorption spectroscopy, Electron Spin Resonance (ESR) and UV-Visible spectroscopy were employed to investigate the structural, morphology, surface area, ions resonance and energy band gap of nanocomposites. The catalytic activity of ZnO/CuO nanocomposites were tested under visible light, ultraviolet light, ultrasound irradiation and the combination of visible/UV light with ultrasound irradiation on the degradation of methylene blue (MB) aqueous solution. The observed catalytic activity of nanocomposites shows that photosonocatalytic has better performance than photocatalytic and sonocatalytic activity. The addition of scavengers suggested that holes are the most important active species in the catalytic mechanism.