Penelitian pemanfaatan fabrikasi plastik biodegradable telah dikembangkan karena bersifat ramah lingkungan dan terbarukan. Tujuan penelitian ini untuk membuat plastik biodegradable dengan filler berupa (kitosan dari limbah kulit udang dan tepung ampas ubi kayu dari limbah ampas ubi kayu) dengan penambahan sorbitol sebagai matrix, serta menganalisa menggunakan uji kuat tarik dengan standar ASTM D-638M, FTIR dan biodegradasi. Hasil penelitian ini didapatkan 4 sampel plastik biodegradable dengan variasi perbandingan komposisi massa filler (kitosan:tepung ampas ubi kayu) masing-masing sampel yaitu A (1,30: 0,70) gr, B (1,35: 0,65) gr, C (1,40: 0,60) gr dan D (1,45: 0,55) gr. Dari hasil uji sifat mekanik didapatkan nilai kuat tarik masing-masing sampel yaitu A (1,01±0,11) MPa, B (1,32±0,08) MPa, C (1,66±0,03) MPa dan D (1,97±0,06) MPa. Sedangkan nilai persen elongasi dari masing-masing sampel yaitu A (23,58 ± 1,39) %, B (16,67 ± 0,20) %, C (11,01 ± 1,32) % dan D (8,11 ± 0,72) %.  Sedangkan nilai persen elongasi dari masing-masing sampel yaitu A (22.89%), B (15.90%), C (10.56%) dan D (7.85%). Penambahan komposisi massa kitosan terbukti mampu meningkatkan nilai kuat tarik dan modulus young plastik biodegradable, namun untuk nilai persen elongasinya menurun. Uji FTIR menunjukkan bahwa di dalam plastik biodegradable terdapat gugus fungsi C-H, O-H, C≡C, C=N, C=C dan C-O yang merupakan gugus organik. Tingginya intensitas ikatan C≡C pada sampel dengan komposisi massa kitosan paling banyak menyebabkan ikatan lebih sukar merenggang/diputus, karena memiliki energi ikatan rata-rata yang tinggi, sehingga menambah nilai kuat tarik dan memperlambat proses biodegradasi.

Graphene and its related materials have attracted much interest in various applications regarding its exceptional physical, chemical, and mechanical properties. Reduction of graphene oxide (GO) from natural resources is recognized as one of the promising methods for low-cost and large-scale production of graphenebased materials. However, the reduction of GO is generally involves the application of toxic and poisonous substances. To counter this challenge, the green reduction which employ non-hazardous substances was introduced by numerous researchers. In this research, the green reduction of graphene oxide from coconut shell was investigated using rose water at room temperature, 70, 80, 90, and 100 o C. The prepared GO and green reduced GO (rGO) were characterized by X-Ray diffraction (XRD), Scanning Electron Microscope -Energy Dispersive X-Ray (SEM-EDX), Fourier transform infrared (FTIR), and I-V measurement. The low-cost and easy-handle green reduction of GO was obtained by immersing in rose water at room temperature which exhibit carbon to oxygen ratio, C/O of 2.97. Moreover, the effect of oxygenated-functional group to the electrical properties was also strongly discussed.

<p style="text-align: justify;">Dye Sensitized Solar Cell (DSSC) with Fluorine deped Tin Oxide (FTO) substrat and nanosize-TiO2 layer sensitized by “dye” ,mangosteen pericarp extract, was succesfully fabricated. Gel-Electrolyte as electron regenerator was synthesized by adding Polyethylene Glycol (PEG) 1000 to electrolyte solution while nanosize-TiO2 was synthesized by co-precipitation method from TiCl3 solution. The crystal size of TiO2 characterized by X-Ray Diffraction is 10.5 nm in size. The solar absorbance of “dye” mangosteen pericarp was measured using UV-Vis Spectrophotometer and it showed that the dye can absorb photon at Near Ultraviolet (NUV) to yellow visible light. Nanosize-TiO2 based DSSC with gel-electrolyte successfully reached short circuit current up to 30.9 μA, open circuit voltage 398.3 mV and performed the long term stability. ©2017 JNSMR UIN Walisongo. All rights reserved</p>

ZnO nanoparticles are semiconductor materials that can be used in Dye Sensitized Solar Cells (DSSC). ZnO nanoparticles can be synthesized using pumpkin peel extract (Cucurbita moschata) which functions as a reducing agent, stabilizer, and capping agent. Zn(CH3COO)2.2H2O precursor was used with a concentration of 0.15 M at various pH 7, 8, and 9 reacted with pumpkin peel extract. The functional groups of pumpkin peel extract were characterized using Fourier Transform Infrared Spectroscopy (FTIR), the samples were analyzed by TEM and XRD. The resulting ZnO nanoparticles were used as semiconductors in Dye Sensitized Solar Cell (DSSC) using dyes from mangosteen peel.The FTIR results showed the presence of functional groups O-H hydroxy, CH2, secondary amides (R-CO-NR2, C-H and phosphate (PO43-). XRD results showed that ZnO produced wurzhite crystals with a hexagonal system and the smallest crystal size was 18.99 nm. TEM results showed that ZnO synthesized at a concentration of 0.15 M and pH 8 had a spherical particle shape with a size of 24.90 nm, while the DSSC test results had an efficiency of 9.06 x 10-4%.

Tujuan penelitian ini adalah menganalisa kerusakan struktur pada lapisan tipis graphene oxide setelah direduksi pada temperatur reduksi yang bervariasi. Lapisan tipis graphene oxide yang disintesis menggunakan metode Hummers direduksi secara termal pada variasi temperatur 350 0 C dan 850 0 C selama 2 jam dalam pemanas vakum (~10-3 Torr). Kuantitas defect sampel dikarakterisasi menggunakan Raman Spectroscopy sedangkan mikrostrukturnya dikarakterisasi menggunakan SEM (Scanning Electron Microscope). Persentase (kuantitas) defect pada graphene oxide dinyatakan dengan ID/IG. Nilai ID/IG graphene oxide, graphene oxide tereduksi pada temperatur 350 0 C dan 850 0 C secara berurutan adalah 0.958, 0.823 dan 1.102. Nilai ID/IG tersebut menunjukkan bahwa kuantitas defect graphene oxide berkurang setelah direduksi pada suhu 350 0 C tetapi bertambah saat direduksi pada suhu 850 0 C. Hasil gambar SEM menunjukkan bahwa lapisan tipis graphene oxide menkerut setalah direduksi pada temperatur 350 0 C dan berubah menjadi material seperti graphite berpori (porous stacked-layer graphite) setelah direduksi pada temperatur 850 0 C. Kata-kata kunci: graphene oxide tereduksi, reduksi termal, kerusakan struktur.