Effect of poling in solar/visible light photocatalysis for binary dye degradation using 0.937(Bi0.5Na0.5)TiO3–0.063BaTiO3

Solar light and visible light active 0.937((Bi_0.5Na_0.5)TiO₃)–0.063(BaTiO₃) (BNT-BT) was examined to investigate the effect of poling in photocatalysis for dye degradation efficacy. To verify the phase, vibrational modes, morphology, chemical composition and band gap of sample, X-ray diffraction (XRD), Raman spectroscopy and field emission scanning electron microscopy (FE-SEM), X-ray photoelectron spectroscopy (XPS) and DRS (diffuse reflectance spectroscopy) were utilized, respectively. In MB (Methylene Blue), RhB (Rhodamine B) and binary dye solution (MB + RhB; 50:50 volume) (10 mg/L) photocatalysis experiments were performed. Using poled sample, the degradation of MB dye was increased significantly to 72 % compared to unpoled sample (48 %). RhB dye degradation increased to 42 %, from 11 % in the poled sample. The poled BNT-BT sample showed enhanced dye degradation in the binary dye solution. The poled sample degraded 73 % MB and 62 % RhB individually, compared to 59 % MB, 23 % RhB in the unpoled sample. Under solar light, poled samples degraded binary dye efficiently (76 % MB, 78 % RhB individually) in 90 min. Next, poled samples were tested at initial binary dye concentrations of 10, 15, and 20 mg/L. Maximum rate constants observed at 10 mg/L (MB: 0.016, RhB: 0.0094 min⁻¹) and minimum at 20 mg/L (MB: 0.006, RhB: 0.0016 min⁻¹).