Visible Light Active 0.95KNbO3-0.05Ba(Nb1/2Sc1/2)O3 Ferroelectric for Enhanced Photocatalytic Activity

This study reports a visible light active Ba/Sc co-doped potassium niobate (KNbO3) ferroelectric material for enhanced photocatalytic applications. Through 5% Ba and Sc co-doping in KNbO3 (i.e., 0.95KNbO(3)-0.05Ba(Nb1/2Sc1/2)O-3), the electronic band gap (E-g) is narrowed down to the visible range of the solar spectrum. The prepared samples are systematically examined by using X-ray diffraction and Raman spectroscopy, which confirms the successful incorporation of Ba and Sc ions into the KNbO3 lattice. Scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) analysis reveal particle morphology and chemical homogeneity of prepared samples. The UV-vis spectroscopy and ferroelectric PE-loop demonstrate enhanced optical absorption compared to host KNbO3 while retaining ferroelectric behavior. The photoelectrochemical (PEC) measurements under visible light irradiation demonstrate a notable enhancement in the photocurrent for 0.95KNbO(3)-0.05Ba(Nb1/2Sc1/2)O-3 (hereafter denoted by 5KBSNO) compared to undoped KNbO3. Additionally, the 5KBSNO sample displays enhanced RhB dye degradation efficiency, reaching approximate to 50% compared to parent KNbO3 (approximate to 30%) under light irradiation. First-principles density functional theory (DFT) calculations are employed to understand the mechanism responsible for the reduced band gap. This study presents a promising material for developing advanced ferroelectric photocatalysts with tailored band structures for efficient solar energy harvesting for energy conversion and contamination remediation applications.