Photocatalytic Degradation of Rhodamine B by Two-Layer Aurivillius Compound SrBi2Ta2O9

Senyawa Aurivillius lapis dua SrBi2Ta2O9 dilaporkan berpotensi sebagai material fotokatalis sehingga dapat digunakan untuk mendegradasi limbah zat warna. Pada penelitian ini telah disintesis senyawa SrBi2Ta2O9 dengan metode reaksi keadaan padatan dan selanjutnya dilakukan uji kemampuan dalam mendegradasi zat warna rhodamine B. Difraktogram menunjukkan bahwa, telah terbentuk senyawa SrBi2Ta2O9 dengan grup ruang A21am dan tidak ditemukan adanya pengotor. Gambar scanning electron microscopy (SEM) menunjukkan bahwa partikel SrBi2Ta2O9 berbentuk plate-like dan teraglomerasi. Spektrum diffuse reflectance spectroscopy menunjukkan bahwa SrBi2Ta2O9 mempunyai energi celah pita sebesar 3,15 eV (~393,60 nm). Hasil uji degradasi larutan rhodamine B menunjukkan bahwa kemampuan SrBi2Ta2O9 dalam mendegradasi adalah 8,6% selama 80 menit. Kemampuan degradasi yang rendah dikarenakan ukuran partikel SrBi2Ta2O9 relatif besar dan dalam keadaan teraglomerasi.   Kata kunci: aglomerasi, fotokatalis, rhodamine B, SrBi2Ta2O9, ukuran partikel.The two-layer Aurivillius compound SrBi2Ta2O9 has been known as a potential photocatalyst as results can be applied to degrade dye waste. In this research, the SrBi2Ta2O9 compound was synthesized using a solid-state reaction and then measured to degrade rhodamine B dye. The diffractogram showed that the SrBi2Ta2O9 compound has formed with space group A21am and there are no impurities. Scanning electron microscopy (SEM) image showed that the shape of SrBi2Ta2O9 particles is plate-like and in agglomeration condition. DRS spectrum showed that the bandgap energy of SrBi2Ta2O9 is 3.15 eV (~ 393.60 nm). The rhodamine B solution's degradation test results showed that the sample could degrade 8.6% rhodamine B for 80 minutes. The low degradability is due to the particles. SrBi2Ta2O9 has a bigger size and also were found agglomeration.   Keywords: agglomeration, particle size, photocatalyst, rhodamine B, SrBi2Ta2O9