Facile prepared high purity Cerium vanadate for simultaneous electrochemical detection of p-nitrophenol and 2,4,6-trichlorophenol

Abstract

The incomplete inner subshell (i.e., 4f) makes rare-earth elements (REE) different from other elements in the periodic table. Incorporating an atomic number across the lanthanide group merely adds an extra electron to the inner 4f rather than the outer shell. To prove this, we tested Nd and Ce doped vanadates as facile and convenient way for simultaneous detection of para-nitrophenol and 2,4,6-trichlophenol via the electrochemical way over modified glassy carbon (GC) electrode (GC/CeVO₄; NdVO₄). For the materials preparation convenient single-step hydrothermal procedure was developed and resulting material (CeVO₄) demonstrate high grade of crystallinity with average size through the crystalline plain (200) equal to 57.4 nm and absence of any additional phases. GC/CeVO₄ electrode was applied for the pioneering study of simultaneous determination of p-nitrophenol (pNP) and 2,4,6-trichlorophenol (TCP) via the SWV method in Britton-Robinson buffer solution at pH5. The developed method of evaluation demonstrate the span of p-nitrophenol calibration graph in range from 0.2 μM to 100 μM with the detection limit 0.058 μM in the presence of 100 μM of 2,4,6-trichlorophenol. The TCP calibration graph comprise concentrations in range from 0.2 μM to 60 μM with the detection limit 0.111 μM in the presence of 100 μM of pNP. Simultaneous determination of pNP and TCP may be performed in range from 0.2 μM up to 60 μM with the limits of detection equal to 0.091 μM for pNP and 0.151 μM for TCP. GC/CeVO₄ electrode demonstrate 9.2 % deviation of pNP signal and 11.3 % of TCP signal deviation within 8 cycles of measurement. Interference study was held with K⁺, Mg²⁺, Sr²⁺, ascorbic acid, citric acid, urea, phenol, resorcinol each taken in 10-fold excess, while the electrode demonstrated retention of signal level not less than 75 % of initial. Application of electrode to tap water investigation had shown the 15 % deviation of pNP signal while the TCP signal stays intact. The abovementioned makes GC/CeVO₄ electrode promising for the evaluation of aromatics in wastewaters.