Enhanced photocatalytic activity of La-substituted BiFeO3 nanostructures on the degradation of phenol red

•La modified BiFeO3 nanostructures have been prepared through hydrothermal method.•Bi1−xLaxFeO3, have nanorod morphology with diameter between 1.5–3 nm.•The photodegradation of phenol red were studied upon visible light irradiation.•Bi1−xLaxFeO3 (x=0.10) show superior photocatalytic activity than other nanostructures.

In this work, we demonstrate enhanced photocatalytic degradation of phenol red (PR) by hydrothermally grown La-substituted bismuth ferrite [Bi1−xLaxFeO3 (x=0.00, 0.05, 0.10 and 0.15)] nanostructures. The photocatalytic activity of Bi1−xLaxFeO3 increases upto 90.1% as x increases from 0.0 to 0.10 and then decreases to 82.6% for x=0.15. Initial characterization of nanostructures shows a substitution induced structural transformation from rhombohedral to orthorhombic for higher concentration of La from X-ray diffraction analysis, a decrease of band gap with the increase of La concentration from the diffused reflectance spectra and a rod like morphology having length between 12–30 nm and diameter about 1.5–3 nm from HR-TEM could be correlated to the photocatalytic degradation behavior of nanostructures. Further, degradation kinetic rates of all samples are described through Langmuir–Hinshelwood model.