<![CDATA[ABSTRAK: Penelitian ini bertujuan untuk mengkaji pengaruh variasi waktu kontak terhadap persentase fotodegradasi metilen biru menggunakan sampel ZnO dan ZnO/Kulit Jeruk (KJ) serta mengkaji model kinetika adsorpsi yang sesuai untuk menggambarkan proses adsorpsi yang terjadi. Material ZnO dan ZnO/KJ disintesis menggunakan metode impregnasi basah dan aktivitas fotokatalitik diamati dibawah Sinar UV LED (365 nm) dengan variasi waktu kontak 0 - 120 menit. Sampel ZnO dan ZnO/KJ dikarakterisasi dengan FTIR, SEM, XRD, DR-UV, dan BET. Kinetika adsorpsi dianalisa menggunakan model orde satu semu dan orde dua semu. Hasil penelitian menunjukkan bahwa presentase degradasi meningkat seiring dengan peningkatan waktu penyinaran. Nilai presentase degradasi terbaik untuk penghilangan metilen biru adalah material ZnO/KJ dengan presentase degradasi terbaik sebesar 67 % pada mode gelap dan 94 % pada mode terang. Sedangkan ZnO hanya mampu mendegradai metilen biru sebesar 46 % pada mode gelap dan 74 % pada mode terang. Berdasarkan data laju adsorpsi menunjukkan bahwa proses adsorpsi ZnO dan ZnO/KJ mengikuti model orde dua semu sehingga dapat disimpulkan bahwa proses adsorpsi yang terjadi melibatkan proses adsorpsi kimia. . ABSTRACT : This study aims to examine the effect of contact time variations on photodegradation percentage of methylene blue using ZnO and ZnO/KJ (orange peel) catalysts as well as to examine the adsorption kinetic models that suitable to describe the adsorption process occured. The ZnO/KJ catalysts was synthesized using the wet impregnation method and the photocatalytic activity was observed under UV LED light (365 nm) with a contact time variation of 0 - 120 minutes. The ZnO and ZnO/KJ catalysts were characterized by FTIR, SEM, XRD, DR-UV, and BET. The adsorption kinetics were obtained using pseudo-first-order and pseudo-second-order models. The results showed that the degradation percentage increased with increasing irradiation time. The highest degradation percentage values of methylene blue using ZnO/KJ catalyst are of 67% in dark mode and of 94% in light mode, respectively. Meanwhile, the ZnO was only able to degrade methylene blue by 46% in dark mode and 74% in light mode. Based on the adsorption rate data, the adsorption process of ZnO and ZnO/KJ follows a pseudo-second order model, so it can be concluded that the adsorption process occured involves a chemisorption process]]>
