Judul: Sintesis Fotokatalis Komposit TiO2/ZnO/CuO untuk Fotodegradasi Pewarna Biru Bromotimol
Abstrak: Fotodegradasi merupakan proses peruraian suatu senyawa dengan bantuan energi foton. Biru bromotimol (BTB) merupakan salah satu pewarna sintetik yang termasuk dalam kelompok zat warna triarilmetana. Fotokatalis komposit TiO2/ZnO/CuO disintesis menggunakan metode sol-gel. Fotokatalis komposit TiO2/ZnO/CuO dikarakterisasi dengan spektroskopi FTIR dan menunjukkan adanya senyawa TiO2, ZnO, dan CuO. Aktivitas fotokatalitik dari komposit TiO2/ZnO/CuO memiliki efektivitas degradasi pada sinar tampak terukur sebesar 63% dengan waktu 60 menit pada suhu 25 oC. Aktivitas fotokatalitik dari komposit TiO2/ZnO/CuO juga memiliki efektivitas degradasi pada sinar UV terukur sebesar 74% dengan waktu 60 menit pada suhu 25 oC. Aktifitas fotokatalik komposit TiO2/ZnO/CuO lebih efektif pada zat warna yang memiliki konsentrasi kecil dibandingkan zat warna dengan konsentrasi besar baik pada sinar tampak maupun sinar UV. Hasil pengamatan menunjukkan adanya peningkatan persentase degradasi setelah fotodegradasi berlangsung. Hal ini diduga karena panjang gelombang komposit tumpang tindih dengan panjang gelombang larutan., Photodegradation is the process of decomposing a compound with the help of photon energy. Bromothymol blue (BTB) is one of the synthetic dyes that belongs to the triarylmethane dye group. TiO2/ZnO/CuO composite photocatalyst was synthesized using the sol-gel method. TiO2/ZnO/CuO composite photocatalyst was characterized by FTIR spectroscopy and showed the presence of TiO2, ZnO, and CuO compounds. The photocatalytic activity of the TiO2/ZnO/CuO composite was measured at visible light with degradation effectiveness of 63% at 60 minutes and 25 oC degrees. Photocatalytic activity of the TiO2/ZnO/CuO composite was also measured at UV degradation with an effectiveness of 74% at 60 minutes and 25 oC degrees. The photocatalytic activity of the TiO2/ZnO/CuO composite was more effective on dyes with small concentrations than dyes with large concentrations in both visible and UV light. The observations showed an increase in the percentage of degradation after photodegradation took place. This occurs due to interference from composite material whose wavelength may overlap with the wavelength of the solution.
Keyword: Bromothymol Blue, Photodegradation, Photocatalyst, TiO2/ZnO/CuO

Judul: Degradasi Zat Warna Metil Jingga menggunakan Fotokatalis Komposit TiO2/ZnO/CuO
Abstrak: Komposit TiO2/ZnO/CuO disintesis menggunakan metode sol-gel. Penelitian ini bertujuan menyintesis, mengkarakterisasi, dan mengukur kinerja komposit TiO2/ZnO/CuO sebagai fotokatalis degradasi zat warna metil jingga. Hasil penelitian sintesis komposit menggunakan metode sol-gel dapat terbentuk. Aktivitas fotokatalis dari komposit TiO2/ZnO/CuO dilakukan dengan variasi konsentrasi 10, 30 dan 50 mg/L dan dengan variasi waktu, yaitu 10, 20, 40, 50 dan 60 menit untuk mendegradasi zat warna metil jingga dibawah sinar UV dan sinar tampak. Hasil penelitian memiliki efektivitas sebesar 53% dibawah sinar UV dengan perbandingan komposit 1:1:0,3 dan 1:1:3 pada waktu ke-40 menit konsentrasi metil jingga 10 mg/L dan sebesar 48% dibawah sinar tampak dengan perbandingan komposit 1:1:0,3 pada konsentrasi metil jingga 10 mg/L diwaktu ke-20 menit. Karakterisasi menggunakan FTIR menunjukkan adanya serapan khas dari gugus fungsi TiO2, ZnO dan CuO serta ikatan dari komposit TiO2/CuO/ZnO., The TiO2/ZnO/CuO composite was synthesized using the sol-gel method. This study aims to synthesize, characterize, and measure the performance of TiO2/ZnO/CuO composites as photocatalysts for the degradation of methyl orange dye. The results of composite synthesis research using the sol-gel method can be formed. The photocatalyst activity of the TiO2/ZnO/CuO composite was carried out with various concentrations of 10, 30 and 50 mg/L and with variations of time, namely 10, 20, 40, 50 and 60 minutes to degrade the methyl orange dye under UV and visible light. The results showed an effectiveness of 53% under UV light with a composite ratio of 1:1:0,3 and 1:1:3 at the 40th minute with a methyl orange concentration of 10 mg/L and 48% under visible light with a composite ratio of 1:1:0,3 at methyl orange concentration of 10 mg/L in the 20th minute. Characterization using FTIR showed that there was a typical absorption of the TiO2, ZnO, and CuO functional groups and bonds from the TiO2/CuO/ZnO composite.
Keyword: Composite, Concentration, Degradation, Methyl orange, Time

Judul: Lejeuneaceae Subfamily Ptychanthoideae (Hepaticae) in  West Java
Abstrak: Subfamily Ptychanthoideae of the family Lejeuneaceae (Hepaticae) in West Java is still poorly known. Publications on this subfamily are out of dated and written in the 19th or early of 20th century. The last taxonomic treatment of Ptychanthoideae of West Java was in 1933, many species names have changed since then. Studies on Ptychanthoideae of West Java are urgently needed. Studies on the Ptychanthoideae were based on the specimens collected from West Java. A total number of 361 of specimens deposited in the Herbarium Bogoriense (BO), Herbarium Biotrop (BIOT), Gottingen Herbarium (GOET) and Bangi Herbarium (UKMB) were examined, those are old and several recent specimens collected in West Java. Recent collections were made from Telaga Warna, Ciater, Gunung Halimun Salak National Park, Cibodas Botanical Garden, Bodogol Education Center and Conservation (Gunung Gede Pangrango National Park), University of Indonesia Campus Depok, including several collections from Banten Province. Twenty four species of Lejeuneaceae subfamily Ptychanthoideae are known from West Java, belonging to 8 genera namely Acrolejeunea (Spruce) Schiffn. (2 species), Archilejeunea (Spruce) Schiffn. (1 species), Lopholejeunea (Spruce) Schiffn. (10 species), Mastigolejeunea (Spruce) Schiffn. (3 species), Ptychanthus Nees (1 species), Schiffneriolejeunea Verd. (1 species), Spruceanthus Verd. (2 species) and Thysananthus Lindenb. (4 species). Two new records of Ptychanthoideae: Mastigolejeunea indica Steph. and Thysananthus minor Verdoorn are reported for Java. A determination key to the species is presented including their descriptions and illustrations.
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