Pengaruh Doping Logam Transisi (Ag, Cu, Fe) Terhadap Kinerja Fotokatalitik g-C3N4 Dalam Degradasi Metilen Biru

Fauzi, Rhodatul Jannah Juni (2026) Pengaruh Doping Logam Transisi (Ag, Cu, Fe) Terhadap Kinerja Fotokatalitik g-C3N4 Dalam Degradasi Metilen Biru. Other thesis, Institut Teknologi Sepuluh Nopember.

Text 5004221120_Undergraduate_Thesis.pdf Restricted to Repository staff only Download (18MB) | Request a copy

Abstract

Graphitic carbon nitride (g-C3N4) merupakan fotokatalis semikonduktor potensial untuk degradasi zat warna seperti metilen biru karena stabilitas kimia yang baik dan kemampuannya bekerja pada cahaya tampak. Namun, kinerjanya masih dibatasi oleh tingginya laju rekombinasi pasangan muatan sehingga diperlukan modifikasi melalui doping logam, yang berperan sebagai pusat penjebak elektron untuk menekan rekombinasi tersebut. Penelitian ini mengkaji pengaruh doping logam transisi (Ag, Cu, dan Fe) terhadap kinerja fotokatalis g-C3N4 dalam degradasi metilen biru. Katalis disintesis melalui metode doping in situ kemudian dikarakterisasi menggunakan XRD, FTIR, UV-DRS dan EIS. Uji fotokatalitik dilakukan dengan menyinari larutan metilen biru 30 ppm menggunakan lampu lampu UV-LED (365 nm) selama 2 jam 30 menit. Hasil karakterisasi menunjukkan bahwa doping logam tidak mengubah struktur dasar g-C3N4, namun memengaruhi sifat optik material melalui pembentukan tingkat energi baru yang meningkatkan penyerapan cahaya tampak dan mendukung pemisahan pasangan muatan. g-C3N4 terdoping Fe dengan kadar dopan 2% memberikan aktivitas tertinggi dengan efisiensi degradasi sebesar 61,32% dengan konstanta laju reaksi (k) sebesar 0,00617 min-1. Diikuti g-C3N4 terdoping Ag (37,7%; k=0,00297 min-1) dan g-C3N4 terdoping Cu(17,42%; k=0,00126 min-1). Keunggulan Fe dikaitkan dengan konfigurasi orbital d yang tidak penuh (3d6), sehingga memungkinkan terjadinya siklus transisi redoks Fe2+/Fe3+ secara dinamis yang efektif sebagai pusat penjebak electron yang mampu menekan rekombinasi pasangan elektron-lubang. Uji scavenger menunjukkan bahwa lubang (h+) merupakan spesies aktif dominan, diikuti oleh radikal superoksida (•O2-) dan elektron (e-) dalam mekanisme fotodegradasi metilen biru.
===================================================================================================================================
Graphitic carbon nitride (g-C3N4) is a promising semiconductor photocatalyst for the degradation of dyes such as methylene blue due to its good chemical stability and ability to operate under visible light. However, its performance remains limited by the high charge carrier recombination, necessitating modification through metal doping, which acts as an electron-trapping center to suppress this recombination. This study aims to examine the effect of transition metal doping (Ag, Cu, and Fe) on the performance of g-C3N4 photocatalysts in methylene blue degradation. The catalysts were synthesized via an in situ doping method and characterized using XRD, FTIR, UV-DRS and EIS. Photocatalytic tests were carried out by irradiating a 30 ppm methylene blue solution using a UV-LED lamp (365 nm) for 2 hours and 30 minutes. Characterization results showed that metal doping did not alter the basic structure of g-C3N4 but influenced its optical properties through the formation of new energy levels that broaden visible-light absorption and facilitate charge carrier separation. Fe-Doped g-C3N4 (2% dopant) exhibited the highest activity, with a degradation efficiency of 61.32%, followed by Ag-Doped g-C3N4 (37.7%) and Cu-Doped g-C3N4(17.42%). The superior performance of Fe was attributed to its partially filled d-orbital configuration (3d6), which enables a dynamic Fe2+/Fe3+ redox cycle, effectively functioning as an electron-trapping center capable of suppressing electron-lubang pair recombination. Scavenger tests indicated that lubangs (h+) were the dominant active species, followed by superoxide radicals (•O2-) and electrons (e-), in the mechanism of methylene blue photodegradation.

Item Type:	Thesis (Other)
Uncontrolled Keywords:	Doping Logam, Fotokatalis, g-C3N4, Logam Transisi, Metilen Biru Metal Doping, g-C3N4, Photocatalyst, Transition Metals, Methylene Blue
Subjects:	Q Science Q Science > QD Chemistry Q Science > QD Chemistry > QD716 Photocatalysis.
Divisions:	Faculty of Science and Data Analytics (SCIENTICS) > Chemistry > 47201-(S1) Undergraduate Thesis
Depositing User:	Rhodatul Jannah Juni Fauzi
Date Deposited:	06 Aug 2026 01:58
Last Modified:	06 Aug 2026 01:58
URI:	http://repository.its.ac.id/id/eprint/144119

Actions (login required)

View Item