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"ZnO/NiBi2O4, NiBi2O4, dan ZnO berhasil disintesis secara green synthesis menggunakan ekstrak daun patikan kebo (EDPK) dalam sistem dua fasa melalui metode sol gel. Hasil sintesis dilakukan karakterisasi menggunakan Spektroskopi FTIR, Spektrofotometer UV-Vis DRS, XRD, dan FE-SEM. Kandungan metabolit sekunder seperti alkaloid, saponin, dan steroid pada ekstrak daun patikan kebo berperan penting dalam proses sintesisyang telah dikarakterisasi dengan FTIR dan Spektrofotometer UV- Vis. Alkaloid berperan sebagai sumber basa lemah sedangkan saponin berperan sebagai capping agent dalam proses sintesis. Didapatkan nilai band gap untuk ZnO/NiBi2O4, NiBi2O4, ZnO masing masing sebesar 2,72eV, 1,83 eV, dan 3,11 eV yang diukur dengan Spektrofotometer UV-Vis DRS. Hasil studi aktivitas fotokatalitik ZnO/NiBi2O4 menunjukkan degradasi malasit hijau yang lebih baik dibandingkan dengan ZnO dan NiBi2O4. Persentase degradasi malasit hijau 5 mg nanokomposit ZnO/NiBi2O4, nanopartikel NiBi2O4, dan nanopartikel ZnO masing masing sebesar 92,30%, 77,33%, dan 55,99 dibawah sinar tampak selama 120 menit.

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In this rearch, ZnO/NiBi2O4, NiBi2O4, and ZnO were successfully synthesized by green synthesis using patikan kebo leaf extract (EDPK) in a two-phase system using the sol gel method. The results of the synthesis were characterized using FTIR Spectroscopy, UV- Vis Spectrophotometer DRS, XRD, and FE-SEM. The content of secondary metabolites such as alkaloids, saponins, and steroids in patikan kebo leaf extract plays an important role in the synthesis process which has been characterized by FTIR and UV-Vis Spectrophotometer. Alkaloids act as a source of weak bases while saponins act as capping agents in the synthesis process. The band gap values for ZnO/NiBi2O4, NiBi2O4, ZnO were 2.72eV, 1.83 eV, and 3.11 eV, respectively, as measured by the DRS UV-Vis Spectrophotometer. The results of the study on the photocatalytic activity of ZnO/NiBi2O4 showed better degradation of green malachite than ZnO and NiBi2O4. The degradation percentage of 5 mg green malachite nanocomposite ZnO/NiBi2O4, NiBi2O4 nanoparticles, and ZnO nanoparticles were 92.30%, 77.33%, and 55.99 respectively under visible light for 120 minutes."

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Green synthesis nanopartikel ZnO, nanopartikel LaFeO₃, dan nanokomposit ZnO/LaFeO₃ berhasil dilakukan menggunakan ekstrak daun mangkokan (Nothopanax Scutellarium) dalam sistem dua fasa dengan metode pengadukan kecepatan tinggi. Senyawa metabolit sekunder yaitu alkaloid digunakan sebagai agen penghidrolisa (sumber basa lemah –OH), sedangkan saponin dan steroid digunakan sebagai agen penstabil (capping agent). Hasil sintesis selanjutnya dikarakterisasi menggunakan instrumentasi spektrofotometer UV-Vis, UV-Vis DRS, spektroskopi FTIR, XRD, PSA, SEM-EDX, dan TEM. Difraktogram nanokomposit ZnO/LaFeO₃ memiliki gabungan nilai difraksi 2θ dari nanopartikel ZnO dan LaFeO₃ yang menunjukkan bahwa tidak terbentuk struktur yang baru. Hasil karakterisasi UV-Vis DRS menunjukkan bahwa nanopartikel ZnO, nanopartikel LaFeO₃, dan nanokomposit ZnO/LaFeO₃ memiliki nilai band gap berturut-turut 3,1 eV; 2,25 eV; dan 2,05 eV. Aktivitas fotodegradasi nanokomposit ZnO/LaFeO₃ terhadap malasit hijau lebih baik daripada nanopartikel ZnO dan LaFeO_3­ dengan persentase berturut-turut sebesar 95,61%; 90,03%; dan 87,58% dibawah sinar tampak selama 2 jam penyinaran. Kinetika fotodegradasi malasit hijau menggunakan nanokomposit ZnO/LaFeO₃ mengikuti reaksi sorde satu semu.

 

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Green synthesis of ZnO nanoparticle, LaFeO₃ nanoparticle, and ZnO/LaFeO₃ nanocomposites have been done by Nothopanax Scutellarium leaf in two phases system with high speed stirring method. Alkaloid, a secondary metabolite compound, is used as hydrolysis agent (base source -OH) and saponin is used as capping agent. Next, synthesized product is characterized by UV-Vis spectrophotometer instrumentation, UV-Vis DRS spectrophotometer, FTIR spectroscopy, XRD, PSA, SEM-EDX, and TEM. Diffractogram ZnO/LaFeO₃ composites have a combined diffraction value at 2θ from ZnO and LaFeO₃ nanoparticles and show that they don’t create a new structure. UV-Vis DRS characterized product shows that ZnO nanoparticle, LaFeO₃ nanoparticle, and ZnO/LaFeO₃ nanocomposites have band gap value at 3,1 eV; 2,25 eV; and 2,05 eV, respectively. Photodegradation activity of malachite green using ZnO/LaFeO₃ nanocomposites is better than ZnO and LaFeO_3­ nanoparticles under visible light for 2 hours of radiation. Degradation percentage of malachite green using ZnO/LaFeO₃ nanocomposites is better than ZnO and LaFeO_3­ nanoparticles for about 95,61%; 90,03%; and 87,58%, respectively. Photodegradation kinetics of malachite green using ZnO/LaFeO₃ nanocomposites follows pseudo first order reaction.

 

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"Pada penelitian, ini dilakukan sintesis nanopartikel ZnO, nanopartikel CeCuO3, dan nanokomposit ZnO/CeCuO3 secara green synthesis menggunakan ekstrak daun bunga matahari (Helianthus annuus L.). Daun bunga matahari mengandung alkaloid yang dapat berperan sebagai basa lemah (ditandai dengan adanya reaksi positif terhadap reagen Wagner) dan mengandung saponin (ditandai dengan adanya reaksi positif terhadap akuades) yang berperan sebagai capping agent pada sintesis nanopartikel dan nanokomposit. Keberhasilan sintesis nanopartikel ZnO, nanopartikel CeCuO3, dan nanokomposit ZnO/CeCuO3 dibuktikan dengan identifikasi struktur yang bersesuaian dengan referensi pada pengujian FTIR dan diperkuat dengan adanya kesesuaian nanopartikel dan nanokomposit yang disintesis dengan database pada karakterisasi menggunakan XRD. Pengkompositan ZnO dengan CeCuO3 dilakukan untuk meningkatkan aktivitas fotokatalitik ZnO di bawah iradiasi sinar tampak dengan menurunkan energi celah pita ZnO. Hal ini dinyatakan pada karakterisasi menggunakan UV-Vis DRS bahwa energi celah pita ZnO, CeCuO3, dan ZnO/CeCuO3 secara berturut - turut sebesar 3,17 eV; 2,60 eV; dan 2,96 eV. Kemudian menghasilkan persentase fotodegradasi yang dihasilkan ZnO/CeCuO sebesar 91% lebih tinggi dibandingkan dengan aktivitas ZnO, yaitu sebesar 56% dan CeCuO3 sebesar 76%. Serta kinetika reaksi fotokatalisis nanokomposit ZnO/CeCuO3 terhadap malasit hijau mengikuti model pseudo orde satu dengan konstanta laju reaksi (k) sebesar 1,85 x 10-2 m-1.

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In this research, synthesis of ZnO nanoparticles, CeCuO3 nanoparticles, and ZnO/CeCuO3 nanocomposites was carried out by means of green synthesis using sunflower (Helianthus annuus L.) leaf extract. Sunflower leaves contain alkaloids which can act as weak bases (indicated by a positive reaction to Wagner's reagent) and contain saponins (indicated by a positive reaction to aquades) which act as capping agents in the synthesis of nanoparticles and nanocomposites. The successful synthesis of ZnO nanoparticles, CeCuO3 nanoparticles, and ZnO/CeCuO3 nanocomposites was proven by the identification of structures that matched the references in FTIR characterization and was strengthened by the suitability of the synthesized nanoparticles and nanocomposites with the database on characterization using XRD. Compositing of ZnO with CeCuO3 was carried out to increase the photocatalytic activity of ZnO under visible light irradiation by reducing the band gap of ZnO. This was stated in the characterization using UV-Vis DRS that the band gaps of ZnO, CeCuO3, and ZnO/CeCuO3 were respectively 3.17 eV; 2.60 eV; and 2.96 eV. Then the photodegradation percentage produced by ZnO/CeCuO3 was 91%, higher than the ZnO activity, which was 56% and CeCuO3, which was 76%. Also, the reaction kinetics of the ZnO/CeCuO3 nanocomposite photocatalyst for green malachite follows a pseudo-first-order model with a reaction rate constant (k) of 1.85 x 10-2 m-1."

"Green synthesis merupakan suatu metode sintesis yang ramah lingkungan dengan memanfaatkan beberapa bagian tanaman (daun, bunga, akar, dan batang), mikroorganisme, dan limbah organik lainnya. Metode ini berhasil digunakan untuk menyintesis nanopartikel ZnO yang dimodifikasi dengan ZrV2O7. Daun tembelekan (Lantana camara L.) memiliki berbagai kandungan metabolit sekunder, seperti alkaloid, saponin, flavonoid, dan polifenol yang berperan dalam proses sintesis nanopartikel. Senyawa alkaloid bertindak sebagai sumber basa lemah dan agen penghidrolisa. Sedangkan, saponin, flavonoid, dan polifenol sebagai capping agent. Karakterisasi UV-Vis DRS, FTIR, XRD, dan SEM-EDS dilakukan untuk menentukan sifat struktural dan optik dari nanomaterial yang diperoleh. Nilai energi celah pita dari nanopartikel ZnO, nanopartikel ZrV2O7, dan nanokomposit ZnO/ZrV2O7 berturut-turut adalah sebesar 3,16 eV, 2,36 eV, dan 2,66 eV. Aktivitas fotokatalitik nanokomposit ZnO/ZrV2O7 terhadap degradasi malasit hijau pada massa optimum 8 mg menunjukkan hasil yang lebih baik dibandingkan nanopartikel ZnO, maupun nanopartikel ZrV2O7. Hasil fotodegradasi untuk nanopartikel ZnO, nanopartikel ZrV2O7, dan nanokomposit ZnO/ZrV2O7 masing-masing sebesar 53,16%, 77,93%, dan 92,00%. Selain itu, kinetika reaksi fotodegradasi nanokomposit ZnO/ZrV2O7 terhadap malasit hijau mengikuti orde satu semu dengan besaran konstanta laju reaksi (k) sebesar 2,056 x 10-2 min-1 .

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Green synthesis is a synthesis method that is more environmentally friendly by utilizing several plant parts (leaves, flowers, roots and stems), microorganisms and other organic wastes. This method was successfully used to synthesize modified ZnO nanoparticles with ZrV2O7. Tembelekan leaves (Lantana camara L.) contain various secondary metabolites, such as alkaloids, saponins, flavonoids, and polyphenols which in the synthesis process of nanoparticles. Alkaloid compounds act as a source of weak base and hydrolyzing agents, while saponins, flavonoids, and polyphenols as capping agent. UV-Vis DRS, FTIR, XRD, dan SEM-EDS characterizations were performed to determine the structural and optical properties of the obtained nanomaterials. The bandgap energy of ZnO nanoparticles, ZrV2O7 nanoparticles, and ZnO/ZrV2O7 nanocomposites were 3,16 eV, 2,36 eV, and 2,66 eV, respectively. Photocatalytic activity of ZnO/ZrV2O7 nanocomposites on the degradation of malachite green at the optimum mass of 8 mg showed better results than ZnO nanoparticles and ZrV2O7 nanoparticles. The degradation percentages obtained for ZnO nanoparticles, ZrV2O7 nanoparticles, and ZnO/ZrV2O7 nanocomposites were 53,16%, 77,93% and 92,00%, respectively. In addition, the kinetics of the photodegradation reaction of the ZnO/ZrV2O7 nanocomposite against malachite green followed the pseudo first-order with a reaction rate constant (k) of 2.056 x 10-2 min-1."

"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."

"ABSTRAKPada studi ini, nanokomposit perak/mangan (II, III) oksida (Ag/Mn3O4) digunakan sebagai fotokatalis untuk mendegradasi limbah organik di bawah paparan cahaya. Sebelumnya, nanokomposit Ag/Mn3O4 telah berhasil dibuat dengan dua tahap, yaitu sintesis nanopartikel Mn3O4 melalui metode konvensional sol-gel dan kemudian sintesis perak dengan penambahan Mn3O4 melalui teknik hidrotermal. Fotokatalis Ag/Mn3O4 dibuat dengan tiga variasi molar dan dua variasi surfaktan seperti cetyltrimethylammonium bromide (CTAB) dan sodium dodecyl sulfate (SDS). Nanopartikel dan nanokomposit tersebut dikarakterisasi dengan menggunakan X-ray Diffraction (XRD), X-ray fluorescence (XRF), energy dispersive X-ray spectroscopy (EDX), N2 adsorption-desorption, ultraviolet-visible diffuse reflectance spectrophotometer (UV-Vis DRS), dan Raman spectroscopy. Hasil pengukuran UV-Vis DRS memperlihatkan semua fotokatalis berada pada rentang cahaya tampak, dan pada pengukuran N2 adsorption-desorption memperlihatkan penambahan surfaktan mengakibatkan peningkatan pada surface area dan pore volume dari nanokomposit Ag/Mn3O4. Keberadaan Ag dan surfaktan juga memengaruhi spektrum Raman. Fotokatalis-fotokatalis yang dibuat mempunyai stabilitas yang baik dan mampu mendegradasi model pewarna organik Congo red. Efektivitas proses photocatalytic meningkat pada fotokatalis Ag/Mn3O4 yang disintesis dengan bantuan surfaktan. Peran spesies yang aktif berkontribusi dalam proses degradasi pewarna organik yang diamati melalui scavenger test menunjukkan urutan sebagai berikut: holes, elektron, superoxide radicals, hydroxil radicals.

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ABSTRACT

In this work, silver/manganese (II, III) oxide (Ag/Mn3O4) nanocomposites were used to degrade organic pollutant under light irradiation. Prior, Ag/Mn3O4 nanoparticles have successfully synthesized in two steps, typically synthesis of Mn3O4 nanoparticle by conventional sol-gel process and then synthesis of Ag featuring Mn3O4 by hydrothermal technique. Ag/Mn3O4 photocatalysts were synthesized using three various molar ratios and two various surfactants such as cetyltrimethylammonium bromide (CTAB) and sodium dodecyl sulfate (SDS). The nanoparticles and nanocomposites were characterized by X-ray diffraction (XRD), X-ray fluorescence (XRF), energy dispersive X-ray spectroscopy (EDX), N2 adsorption-desorption, ultraviolet-visible diffuse reflectance spectrophotometer (UV-Vis DRS), and Raman spectroscopy. The UV-Vis DRS results showed all photocatalysts energy gap are in the visible range, and N2 adsorption-desorption analysis showed the addition of surfactants was enlarged the surface area and pore volume of Ag/Mn3O4 nanocomposites. The presence of Ag and surfactants also influenced the Raman spectra. The as-synthesized photocatalysts have excellent stability and were able to degrade Congo red dye. The effectiveness of photocatalytic process was enhanced in the Ag/Mn3O4 photocatalysts with surfactant-assisted synthesis method. The role of active species contributing to the degradation process that was studied by scavenger test results in the following order: holes, electrons, superoxide radicals, hydroxyl radicals."

"Material fotokatalis MgxZn(1-x)O-Zeolite telah berhasil dilakukan dengan metode kimiawi basah melalui teknik presipitasi dengan variasi konsentrasi Mg (2%, 3%, 6%, dan 7.5%). Seng oksida didapat dari serbuk ZnSO4.7H2O, ion Mg2+ dari MgSO4.7H2O, dan zeolit alam dari clinoptilolite. serangkaian pengujian dilakukan untuk mengkarakterisasi sampel. Uji yang dilakukan adalah uji difraksi sinar-X (XRD), Energy Dispersive X-Ray (EDX), dan spektroskopi UV-Vis. Pengujian aktivitas fotokatalisis sampel dilakukan dengan media degradasi metil jingga. Hasil karakterisasi menunjukkan struktur kristal ZnO tetap berbentuk wurtzite hexagonal. Penambahan doping Mg berpengaruh terhadap penurunan ukuran kristalit sekaligus penurunan kisi yang berdampak pada peningkatan energi celah pita dengan rentang 3.31 ? 3.44 eV pada fotokatalis dengan kadar 2% hingga 7.5%. Peningkatan energi celah pita disebabkan pembentukan Fermi level didalam pita konduksi sehingga pita konduksi terangkat dan jarak untuk eksitasi elektron semakin lebar. Fotokatalis ZnO dengan kadar Mg 2% memiliki efisiensi aktivitas fotokatalisis yang paling baik dari semua sampel, begitu pun dengan laju degradasinya.

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Photocatalyst material MgxZn(1-x)O-Zeolite has been successfully synthesized through the precipitation method with variation of dopant Mg content (2%, 3%, 6%, and 7.5%). Zinc oxide was obtained from ZnSO4.7H2O powder, while Mg2+ ion was obtained from MgSO4.7H2O, and natural zeolite from clinoptilolite. The samples were characterized by X-Ray Diffraction (XRD), Energy Dispersive X-Ray (EDX), and UV-Vis Spectroscopy. The photocatalytic activity was tested for methyl orange degradation under UV irradiation. X-ray diffraction showed the prepared ZnO particles were in wurtzite structure. The addition of Mg doping had an effect on crystallite size reduction as well as reduction of lattice parameter. The band gap energy of MgxZn(1-x)O-Zeolite changed within a range of 3.31 ? 3.44 eV with increasing of Mg content from 2% to 7.5%. This enhancement of band gap energy due to the formation of Fermi level inside the conduction band so that the conduction band was lifted and broaden the distance for photoinduced electron to do the excitation. ZnO photocatalyst with 2% Mg content showed the highest efficiency in photocatalytic activity and also the greatest degradation rate of all samples."

"ABSTRAKNanokomposit Fe-doped ZnO/Aluminosilicate-Base, yaitu Fe-doped ZnO/Montmorillonite dan Fe-doped ZnO/Zeolite telah disintesis menggunakan metode kopresipitasi dengan memvariasikan persentase berat wt. montmorillonite dan zeolite sebanyak 10, 20, 30, dan 40 wt. . Pemberian dopan Fe ke dalam ZnO dilakukan untuk menghambat rekombinasi pasangan electron-hole. Variasi wt. material aluminosilicate-base sebagai pendukung dilakukan untuk mendukung aktivitas photocatalytic dan mendapatkan kandungan maksimum dalam mendegradasi mendegradasi limbah organik methylene blue MB . Sifat struktur, luas permukaan, komposisi, dan sift optik sampel dikarakterisasi menggunakan beberapa pengukuran. Hasil spektroskopi difraksi X-ray XRD menunjukkan fase hexagonal wurtzite dari ZnO pada semua sampel. Luas permukaan spesifik sampel yang dihitung menggunakan spektroskopi Brunauer-Emmett-Teller BET meningkat seiring bertambahnya wt. material aluminosilicate-base. Keberadaan dopan Fe dan elemen Si dan Al dari material pendukung aluminosilicate-base telah dibuktikan melalui spektroskopi fluorosensi X-ray XRF dan spektroskopi inframerah transformasi fourier FTIR . Spektra reflektansi sampel yang direkam dengan spektroskopi reflektansi difusi ultraviolet-visible UV-vis DRS menunjukkan perubahan energi bandgap setelah diolah ke dalam persamaan Kubelka-Munk. Hasil photocatalytic menunjukkan bahwa menambahkan kandungan material aluminosilicate-base hingga 30 wt. dapat meningkatkan aktivitas photocatalytic nanokomposit Fe-doped ZnO/Aluminosilicate-Base dalam mendegradasi MB. Spesies teraktif dalam aktivitas photocatalytic adalah elektron. Degradasi MB terbaik dihasilkan dengan dosis 0.7 g/L dan konsentrasi MB awal 20 mg/L.

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ABSTRACTFe doped ZnO Aluminosilicate Base nanocomposites, consist of Fe doped ZnO Montmorillonite and Fe doped ZnO Zeolite had been synthesized with co precipitation method by varying the weight percentage wt. of montmorillonite and zeolite by 10, 20, 30, and 40 wt. . The dopant Fe was incorporated into ZnO to inhibit the recombination of photogenerated electron hole. Varying the wt. of aluminosilicate base materials was conducted to support the photocatalytic activity and get the maximum content in degrading the methylene blue MB dye. The structural properties, specific surface area, composition, and opcital properties of the samples were characterized by some measurements. The X ray diffraction XRD result showed hexagonal wurtzite structure of ZnO. The specific surface area calculated by Brunauer Emmett Teller BET spectroscopy increased with the content of aluminosilicate base materials. The existance of Fe, Si and Al were confirmed using X ray Fluoroscence XRF and Fourier Transfrm Infrared FTIR spectroscopies. The UV vis Diffuse Reflectance UV vis spectroscopy spectra indicated change in the bandgap value. The photocatalytic result showed that increasing the content of aluminosilicate base materials until 30 wt. could increase the photocatalytic activity of the nanocomposites. The main active species in the photocatalytic activity was electron. The best MB degradation conducted with the dosage of 0.7 g L and 20 mg L of initial dye concentration."

"Nanopartikel ZnO didop Cr disintesis menggunakan metode kopresipitasi untuk empat variasi konsentrasi Cr. Karakteristik nanopartikel dipelajari menggunakan Energy Dispersive X-Ray (EDX), X-Ray Difraction (XRD), Electron Spin Resonance (ESR), Field Emision - Scanning Electron Microscope (FESEM), Fourier Transform-Infrared (FTIR), and spektroskopi Ultra Violet- Visible (UV- Vis). Uji aktivitas nanopartikel diukur melalui degradasi Methyl Orange (MO) dan Methylene Blue (MB) pada daerah sinar Ultraviolet (UV). Hasil menunjukkan keberadaan Cr dan cetyltrimethylammonium bromide (CTAB) dalam sistem ZnO nanopartikel. Nanopartikel yang dihasilkan berfase tunggal dengan struktur heksagonal wurtzite dan mempunyai bentuk spherical-like. Peningkatan konsentrasi dopan Cr dan kehadiran surfaktan kationik CTAB menyebabkan berkurangnya celah energi dan lebih lanjut lagi meningkatkan aktivitas fotokatalitik. Kehadiran surfaktan kationik CTAB menyebabkan nanopartikel ZnO didop Cr lebih efektif dalam mendegradasi zat pewarna anionik MO dibanding kationik MB.

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Cr doped ZnO nanoparticles were synthesized by coprecipitation methods with four variation Cr concentrations. The nanoparticles were characterized by using Energy Dispersive X-Ray (EDX), X-Ray Difraction (XRD), Electron Spin Resonance (ESR), Field Emision - Scanning Electron Microscope (FESEM), Fourier Transform-Infrared (FTIR), and UltraViolet-Visible (UV-Vis) Spectroscopy. The photocatalytic activity of nanoparticles were evaluated by measuring degradation of Methyl Orange (MO) and Methylene Blue (MB) in Ultraviolet (UV) region. The results confirmed the presence of Cr dopant and cationic surfactant cetyltrimethylammonium bromide (CTAB) in the ZnO nanoparticles system. The resulting nanoparticles have single-phases with hexagonal wurzite structures and spherical-like shapes. Increasing the Cr dopant concentrations and the presence of cationic surfactant CTAB cause a reduction in energy gap and more futher improve the photocatalytic activity. The presence of cationic surfactant CTAB causes the Cr doped ZnO nanoparticles were more effective in degrading MO anionic dyes than MB cationic dyes."