Towards nonconventional wastewater treatment methods for the degradation of organic pollutants in wastewater, a perovskite-based photoelectrochemical system was developed. Bismuth ferrite doped with lanthanum (La-BiFeO3, La-BFO) perovskite was synthesised through a hydrothermal method with low calcination temperature for the photoelectrochemical degradation of orange II dye and other cocktails of dyes. Photoanodes were prepared by the deposition of the perovskites on a fluorine-doped tin oxide (FTO) substrate. The photoanodes were characterised using XRD, FESEM, FTIR and UV-vis diffuse reflectance. The photoelectrochemical properties of the synthesised photoanodes were investigated with chronoamperometry and electrochemical impedance spectroscopy (including Mott–Schottky analysis). The results show that all La3+-doped BFO photoanodes exhibited a higher absorption edge in the visible light region than the undoped BFO. The photocurrent response of 10% La-BFO (the best performing electrode) exhibited a three times higher current response than the pure BFO. In addition, the electrode exhibited a good degradation efficiency of 84.2% within 120 min with applied bias potential of 2 V at a pH of 7. EIS studies showed a significant enhancement of the interfacial electron transfer of the charge carriers. The enhancements in electrode performances were attributed to the synergistic effect of the applied bias potential and the introduction of La3+ into the BFO matrix. This study therefore shows that the photoelectrocatalytic performance of BFO for water treatment can be improved by the introduction of perovskites-doping ions such as La3+.

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Explorations into the potential application of dualmetallic iron oxides, (FeXO 3 ), [where X is a transition metal] as heterogeneous electro-Fenton (HEF) catalysts have been of interest due to their enhanced catalytic activity. We thus present the synthesis and application of ilmenite (FeTiO 3 ) nanoparticles as a catalyst for HEF degradation of tetracycline (a pharmaceutical pollutant) in water. The ilmenite nanoparticles were characterized with electron microscopy, X-ray diffraction, Fourier transform IR spectroscopy, and BET analysis prior to their immobilization on a graphite felt (GF) cathode for HEF reactions. The effects of pH and catalyst loading on the HEF process were investigated. The extent of degradation was monitored with UV/vis spectroscopy and total organic carbon (TOC) measurements. The HEF system was robust over a wide pH range. Tetracycline in synthetic and real wastewater matrices was degraded, producing 61 and 40% TOC removal in 2 h, respectively. The comparative studies for the catalytic efficiencies of ilmenite (Ti-doped iron oxide) and commonly used HEF iron oxide catalysts, like magnetite, hematite, and goethite showed that synthetic ilmenite is an effective HEF catalyst for the degradation of organic pollutants in water. A slight Ti cocatalysis effect was observed in ilmenite nanoparticles based on the comparative HEF degradation results catalyzed by pristine iron oxide (hematite, Fe 2 O 3 ) and ilmenite (iron−titanium oxide). Our results show that ilmenite can be reused up to six cycles without loss of activity, and therefore it is an effective HEF catalyst for wastewater treatment.