Application of Novel Zn‐Ferrite Modified Glassy Carbon Paste Electrode as a Sensor for Determination of Cd(II) in Waste Water

Abstract

This paper describes the preparation of a new sensor based on Zn‐ferrite modified glassy carbon paste electrode and its electrochemical application for the determination of trace Cd(II) ions in waste waters using differential pulse anodic stripping voltammetry (DPASV). Different Zn/Ni ferrite nanoparticles were synthesized and characterized using scanning electron microscopy (SEM) and X‐ray powder diffraction (XRPD). The prepared ferrite nanoparticles were used for the preparation of Zn‐ferrite‐modified glassy carbon paste electrode (ZnMGCPE) for determination of Cd(II) at nanomolar levels in waste water at pH 5. The different parameters such as conditions of preparation, Zn2+/Ni2+/Fe2+ ratio and electrochemical parameters, percentage of modifier, accumulation time, pH and accumulation potential were investigated. Besides, interference measurements were also evaluated under optimized parameters. The best voltammetric response was observed for ZnFe2O4 modifier, when the percentage of modifier was 3 %, accumulation time 9 min, pH of supporting electrolyte 5 and accumulation potential −1.05 V. Thus prepared electrode displays excellent response to Cd(II) with a detection limit of 0.38 ppb, and selective detection toward Cd(II) was achieved.

Synthesis of MnCo2O4 nanoparticles as modifiers for simultaneous determination of Pb(II) and Cd(II)

“…Such behavior could be attributed to hydrogen adsorption onto surface of working electrode which was observed before [10,56]. Examination of accumulation time was investigated in the range 50–650 seconds at constant potential -1.4 V. As can be seen from the Fig 10B the current peaks for both Pb(II) and Cd(II) increase to 600 s and then become constant as is described previously [57]. Hence the optimal deposition conditions for simultaneous determination of Pb(II) and Cd(II) on GCE- MnCo 2 O 4 NPs were: accumulation potential of –1.4 V vs. Ag/AgCl, accumulation time of 600 s at pH 2 (H 2 SO 4 /HCl buffer).…”

“…In Fig 11, it can be seen that there is a slight displacement of the peak potentials, in case of Cd(II) only. This displacement can be attributed to overlapping of diffusion layers resulting from the stripping of metal (M 0 ) from the surface of the electrode and the transition of metal ions (M 2+ ) into the solution [57]. Linear ranges of the proposed method were from 0.05 to 40 μmol/dm 3 for Pb(II) whereas oxidation current depends linearly on cadmium concentration in the ranges 0.05–1.6 and 1.6–40μmol/dm 3 .…”

Post‐Transition Metal Electrodes for Sensing Heavy Metal Ions by Stripping Voltammetry

“…Stankovic et al compared different types of ZnFe 2 O 4 and concluded that ZnFe 2 O 4 was the best option for the highest selectivity and responses of different HMIs. [74] They obtained the calibration plot for Cd(II), which was linear in the range of 0.01 to 0.5 µm with a detection limit of 0.38 ppb. Ns et al also investigated the performance of ZnFe 2 O 4 modified electrode for the measurements of Cd(II) and Pb(II) simultaneously.…”

“…For example, the use of tellurium-based electrode was recently reported for the sensing of HMIs. [196] Finally, sustainability and eco-friendliness should be important factors to consider for the [74] ZnO nanofibers [73] Cd(II): 0.38 Pb(II): 0.397 Hg Hanging mercury drop electrode [83] Cd(II): 0.010 Pb(II): 0.010 Ga Hanging Galinstan drop electrode [51,100] Cd(II): 9.0 Pb(II): 2.0…”

Voltammetric determination of vitamin B6 in the presence of vitamin C based on zinc ferrite nano-particles modified screen-printed graphite electrode

“…The cations occupy two different positions in a spinel structure: tetrahedral (Zn) and octahedral (Fe) sites along the face-centered cubic lattice formed by O 2 - cations. The use of bimetallic oxides as electrode materials could enhance both electrical conductivity by two orders of magnitude and electrochemical activity versus materials prepared with unitary metal oxides [ 54 , 55 ].…”