Ruthenium containing perovskites as electrode materials for 4-nitrophenol detection

In this paper, the relationship of structure, type of oxygen defects, valence states of Cr and Ru, and electrochemical properties of La0.7Sr0.3Cr1-XRuXO3 (0 < x < 0.1) perovskite-type oxides were studied. The samples were synthesized by a conventional solid-state reaction method and characterized by powder X-ray diffraction, X-ray fluorescence spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, and electron paramagnetic resonance spectroscopy. The electrochemical performance of these samples was evaluated towards the detection of 4-nitrophenol and strongly depends on the concentration of ruthenium incorporated in the crystal lattice. A new La0.7Sr0.3Cr0.925Ru0.075O3 electrocatalyst with a wide linear concentration range (25–5000 mM) and a detection limit of 8 mM was obtained. These results provide an opportunity for its application in the analysis of real water samples.