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Abstrak :
Pada studi ini, tiga persentase massa dari perak ditambahkan ke nanokomposit oksida nikel dan oksida cerium dengan tiga rasio molar berbeda dari kedua oksida. Nanokomposit telah disintesis menggunakan metode ultrasonic-assisted. Lima teknik karakterisasi digunakan untuk mengevaluasi bahan, X-ray diffraction (XRD), X-ray fluorescence (XRF), UV-Vis diffuse reflectance, Raman Spectroscopy, dan Adsorpsi/Desorpsi Nitrogen. Dua sumber radiasi, cahaya tampak UV digunakan untuk mendegradasi metilen biru sebagai objek polutan untuk aktivitas fotokatalitik. Katalis nanokomposit dengan persentase massa Ag sebanyak 20 wt.% menunjukkan aktivitas fotokatalitik tertinggi. Dalam proses degradasi metilen biru dengan katalis nanokomposit elektron scavenger merupakan spesies aktif utama pada proses degradasi ......In this study, three different weight percentages of silver were added to the nickel oxide and cerium oxide nanocomposites with three different molar ratios of the two oxides. These nanocomposites were synthesized using ultrasonic-assisted techniques. Five characterization techniques were carried out to evaluate the materials, X-ray diffraction (XRD), X-ray fluorescence (XRF), UV-Vis diffuse reflectance, Raman Spectroscopy, and Nitrogen Adsorption/Desorption. Two radiation sources, visible and ultraviolet, were used to degrade methylene blue as a pollutant object for photocatalytic activities. The nanocomposite catalyst with twenty weight percentages of silver showed the highest photocatalytic activity. In the degradation process of methylene blue with these nanocomposite catalyst that electrons becomes the main active species in the process.

Abstrak :
Prototipe sistem portabel dan berbiaya rendah untuk mendeteksi glukosa berbasis potensiostat LMP91000EVM telah dibuat. Karakterisasi elektroda karbon cetak layar tanpa modifikasi (110) dan termodifikasi nikel oksida (110NI) dengan potensiostat komersial untuk melihat pengaruh nikel oksida dalam mendeteksi glukosa. Melalui metode spektroskopi impedansi elektrokimia, diperoleh nilai Rct sebesar 1276,79 Ω untuk sensor 110NI dan 429,06 Ω untuk sensor 110, sehingga sensor 110NI memiliki laju transfer elektron yang lebih lambat. Sementara itu, melalui metode voltametri siklik, diperoleh luas permukaan elektroda aktif sebesar 7,1×10-2 cm2 untuk sensor 110NI dan 6,9×10-2 cm2 untuk sensor 110, sehingga sensor 110NI lebih sensitif dalam mendeteksi glukosa. Saat konsentrasi glukosa divariasikan, nilai LOD dan LOQ sensor 110NI lebih kecil yaitu 1,807 mM dan 6,024 mM daripada sensor 110 yaitu 2,629 mM dan 8,762 mM, sehingga sensor 110NI lebih sensitif. Saat laju pemindaian divariasikan, nilai gradien sensor 110NI lebih kecil yaitu -8,14×10-4 mA s/mV daripada sensor 110 yaitu -9,62×10-4 mA s/mV, sehingga sensor 110NI tidak lebih sensitif. Selanjutnya, membandingkan prototipe sistem yang penguatan TIA divariasikan dan potensiostat komersial. Hasilnya, voltammogram siklik setiap siklus pada potensiostat komersial lebih stabil. Semakin kecil penguatan TIA pada prototipe sistem, semakin stabil, hal ini karena noise yang ikut dikuatkan semakin kecil. ......A portable and low-cost system prototype for glucose detector based on LMP91000EVM potentiostat has been created. Characterization of screen-printed carbon electrodes without modification (110) and modified nickel oxide (110NI) was carried out with a commercial potentiostat to see the effect of nickel oxide in detecting glucose. Through the electrochemical impedance spectroscopy method, the Rct value of 1276,79 Ω is obtained for the 110NI sensor and 429,06 Ω for the 110 sensor, so that the 110NI sensor has a slower electron transfer rate. Meanwhile, through the cyclic voltammetry method, the surface active electrode area is 7,1×10-2 cm2 for the 110NI sensor and 6,9×10-2 cm2 for the 110 sensor, so that the 110NI sensor is more sensitive in detecting glucose. When the glucose concentration is varied, the LOD and LOQ values of the 110NI sensor are smaller, specifically 1,807 mM and 6,024 mM than the 110 sensor, specifically 2,629 mM and 8,762 mM, so the 110NI sensor is more sensitive. When the scan rate is varied, the gradient value of the 110NI sensor is smaller, specifically -8,14×10-4 mA s/mV than the 110 sensor, specifically -9,62×10-4 mA s/mV, so the 110NI sensor is not more sensitive. Next, comparing a prototype system that TIA gain is varied and a commercial potentiostat. As a result, the cyclic voltammogram per cycle on commercial potentiostat is more stable. The smaller the TIA gain on the system prototype, the more stable it is, this is because the noise that is amplified is getting smaller.