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"Green synthesis nanopartikel Nd2O3, Ag2O dan nanopartikel Nd2O3-Ag2O dilakukan karena mudah, murah dan ramah lingkungan. Dalam penelitian ini, ekstrak daun afrika (Vernonia Amygdalina Del.) kemudian diberi nama EDA digunakan untuk mensintesis nanopartikel Nd2O3-Ag2O. Metabolit sekunder pada EDA berperan sebagai sumber basa dan capping agent, yang ditentukan melalui uji fitokimia. Pola difraksi dan kristalinitas ketiga nanopartikel tersebut dikonfirmasi menggunakan X-Ray Diffraction, sedangkan morfologi ditentukan menggunakan Scanning Electron Microscopy-Energy Dispersive X-ray Analysis dan Transmitted Electron Microscopy. Fourier Transform-Infra Red digunakan untuk menunjukkan interaksi antara EDA dengan nanopartikel. Bilangan gelombang Nd-O pada nanopartikel Nd2O3 muncul di daerah 426 cm-1, Ag-O pada nanopartikel Ag2O di daerah 825 cm-1. Sedangkan bilangan gelombang Ag-O (855 cm-1), Nd-O (424 dan 667 cm-1) terdapat pada nanopartikel Nd2O3-Ag2O. Ukuran distribusi dari ketiganya berada di antara 1-100 nm yang dikonfirmasi menggunakan Particle Size Analyzer. Band gap nanopartikel Nd2O3-Ag2O yaitu sebesar 3,29 eV. Aktivitas fotokatalitik nanopartikel Nd2O3-Ag2O disimulasikan terhadap degradasi Metilen Biru (MB). Hasil degradasi sebesar 93, 71%.

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Green synthesis of Nd2O3, Ag2O and Nd2O3-Ag2O nanoparticles has been investigated lately due to its properties of inexpensive, easy to use, and eco-friendly material. At current research, Vernonia amygdalina Del. leaf extract was used to synthesize Nd2O3, Ag2O and Nd2O3-Ag2O nanoparticles. The secondary metabolite of Vernonia amygdalina Del. leaf extract plays a role as a base source and a capping agents, which can be determined by phytochemical test. The diffraction pattern and crystallinity of Nd2O3, Ag2O and Nd2O3-Ag2O nanoparticles were confirmed by using X-ray Diffraction, while the morphology can be determined using Scanning Electron Microscopy-Energy Dispersive X-ray Analysis and Transmitted Electron Microscopy. Fourier Transform-Infra Red (FT-IR) spectra was used to show the interaction between Vernonia amygdalina Del. leaf extract and nanoparticles. FT-IR characterization showed the wave number of Nd2O3 at 426 cm-1, Ag2O at 825 cm-1, and Nd2O3-Ag2O nanoparticles at 424 and 855 cm-1. The size distribution of Nd2O3, Ag2O and Nd2O3-Ag2O nanoparticles at 1-100 nm were confirmed by Particle Size Analyzer. UV-Vis DRS characterization proved the energy band gap of Nd2O3-Ag2O nanoparticles at 3,29 eV. The photocatalytic activity of Nd2O3-Ag2O nanoparticles was observed by determining the degradation of methylene blue, which was identified at 93.71%."

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Diabetes melitus adalah penyakit yang ditandai dengan kondisi hiperglikemik dan akumulasi stress oksidatif mikrovaskular. Tanaman daun afrika (Vernonia amygdalina) diketahui memiliki efek antidiabetes dan antioksidan, sehingga berpotensi sebagai terapi alternatif dari diabetes melitus. Penelitian ini menguji aktivitas antioksidan dan antidiabetes ekstrak air dan ekstrak etanol tanaman daun afrika dengan metode inhibisi DPPH dan enzim α-glukosidase serta menginvestigasi metabolit sekunder yang terkandung pada tiap ekstrak. Tanaman daun afrika diekstraksi dengan menggunakan pelarut etanol, air, dan campuran air:etanol (1:1). Tiap ekstrak dilakukan skrining fitokimia, kromatografi lapis tipis, dan LC-MS. Selanjutnya, dilakukan uji inhibisi  ekstrak tanaman daun afrika terhadap radikal bebas DPPH dan enzim α-glukosidase. Aktivitas inhibisi dinyatakan dengan nilai IC50. Perbedaan komposisi air dan etanol mempengaruhi aktivitas antioksidan dan kandungan metabolit sekunder, tetapi tidak mempengaruhi aktivitas antidiabetes dari ekstrak daun afrika. Ekstrak campuran air:etanol (1:1) mempunyai aktivitas antioksidan dan antidiabetes yang lebih tinggi daripada ekstrak air dan ekstrak etanol daun afrika. Skrining fitokimia menunjukkan adanya kandungan alkaloid, tanin, saponin, dan terpenoid. IC50 dari ekstrak campuran air:etanol (1:1) terhadap DPPH adalah 418,5 µg/mL, sedangkan nilai IC50 terhadap enzim α-glukosidase adalah 585,8 µg/mL. Ekstrak campuran air:etanol (1:1) tanaman daun afrika dapat dikembangkan lebih lanjut sebagai antioksidan dan antidiabetes.

 

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Diabetes mellitus is a disease characterized by hyperglycemic conditions that can cause various complications through the accumulation of microvascular oxidative stress. Bitter leaf plants (Vernonia amygdalina) are known to have antidiabetic and antioxidant effects, so they have the potential as an alternative therapy for diabetes mellitus. This research is conducted to analyze the antioxidant and antidiabetic activity of water and ethanolic extract of Vernonia amygdalina measured by using DPPH and α-glucosidase inhibition and investigated its secondary metabolites contained. The extraction of Vernonia amygdalina was conducted using ethanol, water, and a mixture of water:ethanolic (1:1). Each extract was analyzed by phytochemical screening, and LC-MS. The extract of Vernonia amygdalina were then tested for its inhibition acitivity toward DPPH  and α-glucosidase enzyme. The inhibition activity of each tests was calculated in IC50 value. The composition of water and ethanol solvents affects the antioxidant activity and its secondary metabolites, but not the antidiabetic acitivity in Vernonia amygdalina extract. The mixed water extract:ethanolic (1:1) had higher antioxidant and antidiabetic activity than the water extract and the ethanol extract of Vernonia amygdalina leaves. Phytochemical screening showed the presence of alkaloids, tannins, saponins, and terpenoids. The IC50 value of the water:ethanol (1:1) mixture extract against DPPH was 418.5 µg/mL and the IC50 value for α-glukosidase enzyme was 585.8 µg/mL. The mixture of water:ethanolic (1:1) extract of Vernonia amygdalina could be observed and improved further as an antioxidant and antidiabetec agents.

 

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"Pada penelitian ini, nanopartikel ZnO, nanopartikel CuCr2O4, dan nanokomposit ZnO/CuCr2O4 telah berhasil disintesis dengan metode green synthesis menggunakan ekstrak daun putri malu (Mimosa pudica L) dalam sistem dua fasa. Ekstra n-heksana daun putri malu memilki kandungan metabolit sekunder berupa alkaloid, saponin, dan steroid yang berperan sebagai basa lemah dan capping agent. Nanopartikel ZnO, nanopartikel CuCr2O4, dan nanokomposit ZnO/CuCr2O4 dikarakterisasi menggunakan Spektroskopi FTIR, UV-Vis DRS, XRD, dan FE-SEM EDX. Energi band gap nanopartikel ZnO, nanopartikel CuCr2O4, dan nanokomposit ZnO/CuCr2O4 yang diperoleh menggunakan UV-Vis DRS sebesar 3,13 eV; 1,57 eV; dan 2,75 eV. Hasil uji aktivitas fotokatalitik nanokomposit ZnO/CuCr2O4 terhadap larutan malasit hijau di bawah iradiasi sinar tampak selama 120 menit memiliki persen degradasi yang lebih baik dibandingkan dengan nanopartikel ZnO dan nanopartikel CuCr2O4. Persen degradasi dari nanopartikel ZnO, nanopartikel CuCr2O4, dan nanokomposit ZnO/CuCr2O4 yang diperoleh berturut-turut sebesar 51,08%, 84,47%, dan 96,73%.

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In this research, ZnO nanoparticles, CuCr2O4 nanoparticles, and ZnO/CuCr2O4 nanocomposites have been successfully synthesized by the green synthesis method using the extract of Putri malu leaves (Mimosa pudica L) in a two-phase system. The n- hexane extract from the Putri malu leaves contains secondary metabolites in the form of alkaloids, saponins, and steroids which act as weak bases and capping agents. ZnO nanoparticles, CuCr2O4 nanoparticles, and ZnO/CuCr2O4 nanocomposites were characterized using FTIR Spectroscopy, UV-Vis DRS, XRD, and FE-SEM EDX. The band gap energy of ZnO nanoparticles, CuCr2O4 nanoparticles, and ZnO/CuCr2O4 nanocomposites obtained using UV-Vis DRS was 3.13 eV; 1.57 eV; and 2.75 eV. The results of the photocatalytic activity test of ZnO/CuCr2O4 nanocomposite against malachite green solution under visible light irradiation for 120 minutes had a significant degradation percentage compared to ZnO nanoparticles and CuCr2O4 nanoparticles. Percent degradation of ZnO nanoparticles, CuCr2O4 nanoparticles, and ZnO/CuCr2O4 nanocomposites obtained were 51.08%, 84.47%, and 96.73%, respectively."

"Sintesis hijau adalah suatu metode sintesis yang memanfaatkan metabolit sekunder menggunakan bagian-bagian tanaman seperti daun, bunga, akar, dan batang. Daun bambu ampel (Bambusa vulgaris) memiliki kandungan metabolit sekunder yaitu alkaloid, flavonoid, dan saponin. Dilakukan karakterisasi menggunakan instrumen Spektrofotometer UV-Vis, UV-Vis DRS, Spektroskopi FTIR, XRD, dan SEM-EDX untuk mengetahui struktur, sifat optik, dan morfologi dari nanopartikel ZnO, nanopartikel SnNb2O6, dan nanokomposit ZnO/SnNb2O6. Nanopartikel ZnO dengan nilai energi celah pita 3,08 eV berhasil dikompositkan dengan SnNb2O6 yang memiliki nilai energi celah pita 2,85 eV menghasilkan nanokomposit ZnO/SnNb2O6 dengan nilai energi celah pita 2,73 eV. Aktivitas fotokatalitik nanokomposit ZnO/SnNb2O6 terhadap degradasi malasit hijau pada massa optimum 8 mg menunjukkan hasil yang lebih baik dibandingkan nanopartikel ZnO, maupun nanopartikel SnNb2O6. Hasil fotodegradasi untuk nanopartikel ZnO, nanopartikel SnNb2O6, dan nanokomposit ZnO/SnNb2O6 masing-masing sebesar 61,36%; 78,7%; dan 92,94%. Reaksi fotodegradasi yang dilakukan terhadap malasit hijau menggunakan nanokomposit ZnO/SnNb2O6 mengikuti kinetika laju orde satu semu dengan konstanta laju reaksi sebesar 1,98 x 10-2 M.

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Green synthesis is a synthesis method that utilizes secondary metabolites using plant parts such as leaves, flowers, roots and stems. ZnO and SnNb2O6 were successfully synthesized using common bamboo leaf extract (Bambusa vulgaris) using the green synthesis method. Common bamboo leaves contain secondary metabolites, namely alkaloids, flavonoids, and saponins. Characterization was carried out using a UV-Vis Spectrophotometer, UV-Vis DRS, FTIR Spectroscopy, XRD, and SEM-EDX spectroscopy to determine the structure, optical properties, and morphology of ZnO nanoparticles, SnNb2O6 nanoparticles, and ZnO/SnNb2O6 nanocomposites. ZnO nanoparticles (Eg = 3.08 eV) were successfully combined with SnNb2O6 (Eg = 2.85 eV) to produce a ZnO/SnNb2O6 nanocomposite (Eg = 2.73 eV). The photodegradation results for ZnO nanoparticles, SnNb2O6 nanoparticles, and ZnO/SnNb2O6 nanocomposites were 61.36%, 78.17%, and 92.94%, respectively. The photodegradation reaction carried out on malachite green using ZnO/SnNb2O6 nanocomposites follows pseudo-first order kinetics with a reaction rate constant of 1.98 x 10-2 M."

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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."

"Pada penelitian ini, nanopartikel ZnO, nanopartikel NiCr2O4, serta nanokomposit ZnO/NiCr2O4 berhasil untuk disintesis menggunakan metode green synthesis dengan ekstrak daun randu (Ceiba pentandra). Ekstrak daun randu mengandung senyawa metabolit sekunder yaitu alkaloid, saponin, dan polifenol, dibuktikan dengan karakterisasi FTIR dan spektroskopi UV-Vis. Alkaloid berperan sebagai sumber basa lemah, sedangkan saponin dan polifenol berperan sebagai capping agent dalam proses sintesis nanopartikel dan nanokomposit. Berdasarkan hasil dari karakterisasi menggunakan Spektrofotometer UV-Vis DRS, didapatkan nilai band gap dari nanopartikel ZnO, nanopartikel NiCr2O4, dan nanokomposit ZnO/NiCr2O4 berturut-turut adalah sebesar 3,0 eV, 1,95 eV, dan 2,63 eV. Hasil dari uji aktivitas fotokatalitik dari nanokomposit ZnO/NiCr2O4 terhadap larutan rifampisin selama 120 menit di bawah iradiasi sinar tampak menunjukkan nanokomposit ZnO/NiCr2O4 memiliki persentase fotodegradasi yang paling baik daripada nanopartikel ZnO dan nanopartikel NiCr2O4. Persentase fotodegradasi yang didapatkan dari nanopartikel ZnO, nanopartikel NiCr2O4, dan nanokomposit ZnO/NiCr2O4 berturut-turut adalah sebesar 12,25%, 42,37%, dan 97,37%. Kinetika reaksi untuk fotodegradasi nanokomposit ZnO/NiCr2O4 terhadap rifampisin mengikuti pseudo orde satu dengan tetapan laju sebesar 9,35 x 10-3 min-1.

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In this research, ZnO nanoparticles, NiCr2O4 nanoparticles, and ZnO/NiCr2O4 nanocomposites have been successfully synthesized by means of green synthesis method using Randu (Ceiba pentandra) leaf extract. Randu leaf extract contains secondary metabolites, including saponins, and polyphenols, as evidenced by FTIR and UV-Vis spectroscopy. The alkaloids acted as a source of weak bases, while saponins and polyphenols acted as capping agents in the synthesis of nanoparticles and nanocomposite process. Based on DRS UV-Vis measurement results, the band gap values of ZnO nanoparticles, NiCr2O4 nanoparticles, and ZnO/NiCr2O4 nanocomposites were 3.0 eV, 1.95 eV, and 2.63 eV, respectively. Meanwhile, the results of the photocatalytic activity test of the ZnO/NiCr2O4 nanocomposites in rifampicin solution photodegradation for 120 minutes under visible light irradiation, showed that ZnO/NiCr2O4 nanocomposites had the best percentage of photodegradation than ZnO nanoparticles and NiCr2O4 nanoparticles. The degradation percentages of ZnO nanoparticles, NiCr2O4 nanoparticles, and ZnO/NiCr2O4 nanocomposites were 12.25%, 42.37%, and 97.37%, respectively. Reaction kinetics for photodegradation of ZnO/NiCr2O4 nanocomposites to rifampicin followed pseudo-first order model with the rate constant 9,35 x 10-3 min-1."

"Pada penelitian ini, sintesis nanopartikel ZnO, nanopartikel Ce2Sn2O7, dan nanokomposit ZnO/Ce2Sn2O7 berhasil dilakukan dengan metode green synthesis menggunakan ekstrak daun kirinyuh (Chromolaena odorata L.). Kandungan metabolit sekunder pada daun kirinyuh seperti alkaloid dan saponin dimanfaatkan sebagai basa lemah dan capping agent dalam proses sintesis. Karakterisasi FTIR, XRD, UV-Vis DRS, dan FESEM-EDX dilakukan untuk mengetahui sifat struktural, optik, maupun morfologi dari nanopartikel dan nanokomposit yang dihasilkan. Berdasarkan hasil karakterisasi menggunakan UV-Vis DRS, diperoleh nilai energi band gap dari nanopartikel ZnO, nanopartikel Ce2Sn2O7, dan nanokomposit ZnO/Ce2Sn2O7 masing-masing sebesar 3,00 eV; 2,41 eV; dan 2,52 eV. Selain itu, hasil uji fotokatalitik menunjukkan bahwa nanokomposit ZnO/Ce2Sn2O7 memiliki aktivitas fotokatalitik yang paling baik dibandingkan nanopartikel ZnO dan Ce2Sn2O7 dalam mendegradasi rifampicin di bawah sinar tampak selama 120 menit. Persen fotodegradasi rifampicin oleh ZnO/Ce2Sn2O7, Ce2Sn2O7, dan ZnO berturut-turut sebesar 92,25%; 68,57%; dan 55,38%. Lebih lanjut, reaksi fotodegradasi rifampicin menggunakan ZnO/Ce2Sn2O7 mengikuti kinetika laju pseudo orde satu.

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In this research, synthesis of ZnO nanoparticles, Ce2Sn2O7 nanoparticles, and ZnO/Ce2Sn2O7 nanocomposites were successfully carried out by means of green synthesis method using siam weed (Chromolaena odorata L.) leaf extract. The secondary metabolites in siam weed leaf such as alkaloids and saponins were used as weak bases and capping agents in the synthesis process. FTIR, XRD, UV-Vis DRS, and FESEM-EDX measurements were conducted to elucidate the structural, optical, and morphological properties of nanoparticles and nanocomposites. Based on the results of characterization using UV-Vis DRS, the band gap energy values ​​of ZnO nanoparticles, Ce2Sn2O7 nanoparticles, and ZnO/Ce2Sn2O7 nanocomposites were 3.00 eV, 2.41 eV, and 2.52 eV. In addition, the photocatalytic test results showed that ZnO/Ce2Sn2O7 nanocomposites had the best photocatalytic activity compared to ZnO and Ce2Sn2O7 nanoparticles against rifampicin under visible light for 120 minutes. Rifampicin photodegradation percentage by ZnO/Ce2Sn2O7, Ce2Sn2O7, and ZnO obtained were 92.25%, 68.57%, dan 55.38%, respectively. Additionally, the reaction kinetics of rifampicin photodegradation using ZnO/Ce2Sn2O7 was found to be a pseudo-first-order rate."

"Pada penelitian ini, nanopartikel ZnO, NiWO4, dan ZnO/NiWO4 berhasil disintesis dengan cara metode green synthesis menggunakan ekstrak daun alpukat (Persea americana) dalam sistem satu fasa. Kandungan ekstrak air daun alpukat adalah alkaloid, saponin dan polifenol. Nanopartikel ZnO, NiWO4, dan ZnO/NiWO4 dikarakterisasi menggunakan spektrofotometer Ultraviolet-Visible Diffuse Reflectance Spectroscopy (UV-Vis DRS), X-Ray Diffraction (XRD), Fourier Transform InfraRed (FTIR), Transmission Electron Microscopy (TEM) dan Scanning Electron Microscopy Energy Disperse X-Ray (SEM-EDX). Hasil karakterisasi UV-Vis DRS, nanopartikel ZnO, NiWO4, dan ZnO/NiWO4 memiliki band gap 3,15 eV, 2,35 eV, dan 3,03 eV. Hasil uji aktivitas fotokatilitiknya menggunakan nanokomposit ZnO/NiWO4 terhadap malasit hijau dibawah iradiasi sinar tampak selama 2 jam memiliki persen degradasi tertinggi dibandingkan dengan NiWO4 dan ZnO. Persen degradasi ZnO/NiWO4, NiWO4, ZnO adalah 96,20%, 79,22%, 48,30%.

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In this research, ZnO, NiWO4, and ZnO/NiWO4 nanoparticles were successfully synthesized by means of green synthesis method using avocado (Persea americana) leaf extract in a single phase system. The secondary metabolites of avocado leaf water extract are alkaloids, saponins and polyphenols. ZnO, NiWO4, and ZnO/NiWO4 nanoparticles were characterized using a spectrophotometer Ultraviolet-Visible Diffuse Reflectance Spectroscopy (UV-Vis DRS), X-Ray Diffraction (XRD), Fourier Transform InfraRed (FTIR), Transmission Electron Microscopy (TEM) and Scanning Energy Microscopy Electron Disperse X-Ray (SEM-EDX). The results of the photocathylytic activity test using the ZnO/NiWO4 nanocomposite against malachite green under visible light irradiation for 2 hours had the highest degradation percent compared to NiWO4 and ZnO. The degradation percentages of ZnO/NiWO4, NiWO4, ZnO were 96.81%, 79.71%, 51.38%."

"Pada penelitian ini, sintesis nanokomposit ZnO/CeMnO₃ dilakukan dengan metode green synthesis menggunakan ekstrak daun bayam raja (Amaranthus viridis). Metabolit sekunder pada ekstrak digunakan sebagai basa lemah dan capping agent dalam proses sintesis nanokomposit. Untuk mengidentifikasi sifat optik dan struktural nanopartikel serta nanokomposit, dilakukan dikarakterisasi dengan instrumen UV-Vis DRS, FTIR, XRD, Photoluminescence, SEM-EDX, dan HRTEM. Nanokomposit ZnO/CeMnO₃ menunjukkan nilai band gap yang menurun dibanding ZnO, yaitu pada 2,68 eV. Selain itu, karakterisasi HRTEM mengkonfirmasi terbentuknya ZnO/CeMnO₃ heterojunction dengan d spacing ZnO (110) = 0,162 nm dan d spacing CeMnO₃ = 0,31 nm. Ukuran partikel rata-rata ZnO/CeMnO₃ adalah 7,46 nm. Aktivitas fotokatalitik nanokomposit ZnO/CeMnO₃ diuji untuk mendegradasi larutan malasit hijau di bawah sinar tampak selama 120 menit serta dibandingkan dengan aktivitas fotokatalitik nanopartikel ZnO dan CeMnO₃. Persentase fotodegradasi malasit hijau oleh ZnO/CeMnO₃, CeMnO₃, dan ZnO masing-masing bernilai 92,69%; 69,46%; dan 37,5%. Kinetika reaksi fotodegradasi nanokomposit ZnO/CeMnO₃ mengikuti model orde satu semu dengan konstanta laju senilai 1,031 x 10^-2 min^-1. Peningkatan aktivitas fotokatalitik nanokomposit ZnO/CeMnO₃ disebabkan karena adanya penurunan bandgap ZnO dan rendahnya laju fotorekombinasi electron-hole yang masing-masing dibuktikan oleh analisis spektroskopi UV-Vis DRS dan photoluminescence.

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In this study, ZnO/CeMnO₃ nanocomposites were synthesized using green synthesis method using green amaranth leaf extract (Amaranthus viridis). The secondary metabolites present in the extract were utilized as a weak base and capping agent during the synthesis processes. To identify the optical and structural properties of the synthesized nanoparticles and nanocomposites, characterization was performed using UV-DRS, FTIR, XRD, Photoluminescence, SEM-EDX, and HRTEM instruments. The synthesized ZnO/CeMnO₃ nanocomposite showed a decreased band gap value compared to ZnO, at 2,68 eV. Additionally, XRD and HRTEM characterization confirmed the formation of the ZnO/CeMnO₃ composite on a nanometer scale with the average particle size at 7,46 nm. The photocatalytic activity of the ZnO/CeMnO₃ nanocomposite was tested by degrading a malachite green solution under visible light for 120 minutes and compared with the photocatalytic activity of ZnO and CeMnO3 nanoparticles. The percentages of malachite green photodegradation by ZnO/CeMnO₃, CeMnO₃, and ZnO were 92,69%; 69,46%; and 37,5%, respectively. The photodegradation reaction kinetics of the ZnO/CeMnO₃ nanocomposite were also determined to follow a pseudo-first-order model with a rate constant of 1.031 x 10^-2 min^-1. The increase in photocatalytic activity of the ZnO/CeMnO₃ nanocomposite is due to a decrease in the bandgap and a low rate of electron-hole photorecombination which is proven by UV-Vis DRS and photoluminescence analysis respectively."