In this study, 2-aminobenzoic acid (ABA) has been used as complexing ligand for simultaneousdetermination of metal ions by adsorptive cathodic stripping voltammetry (AdCSV), for the firsttime. Thus, a selective and sensitive procedure was presented for simultaneous determination oflead, cadmium and nickel using ABA and differential pulse-adsorptive cathodic strippingvoltammetry (DP-AdCSV). The method was based on adsorptive accumulation of the complexes ofPb(II), Cd(II) and Ni(II) ions with ABA onto hanging mercury drop electrode (HMDE), followedby reduction of adsorbed species by differential pulse cathodic stripping voltammetry. The effect ofexperimental parameters such as pH, ABA concentration, accumulation time and potentialand scanrate on the electrode response was examined. Under the optimized conditions, linear calibrationcurves were established for the concentration of Pb(II), Cd(II) and Ni(II) in the ranges of 5-150, 5-120 and 5-150 ng mL-1, respectively. Detection limits of 1.78, 2.26 and 1.78 ng mL-1 were obtainedfor Pb(II), Cd(II) and Ni(II), respectively. An application of the proposed method was reported fordetermination of these elements in tap water and industrial waste water of as real samples. Manuscript profile

In this work, the photoelectrocatalytic (PEC) degradation of 2,5-dichlorophenol can be used for its removal from aqueous solution. To study this activity, a TiO2 thin film modified titanium sheet (TiO2/Ti) was fabricated by anodizing Ti plates using a two electrode system under the constant bias voltage of 20 V for 20 min in a solution of 0.2% (v/v) HF followed by calcination at 500 oC for 2 h. Then, the electrochemical properties of 2,5-dichlorophenol were compared on the surface of the TiO2/Ti and unmodified Ti electrodes. Consequently, the TiO2/Ti was applied for PEC degradation of 2,5-dichlorophenol. It was found that 2,5-dichlorophenol could be degraded more efficiently by this photoelectrocatalysis process than the sum of degradation obtained by photocatalytic (PC) and electrochemical (EC) oxidation so that the amount of 2,5-dichlorophenol degraded by PEC, PC and EC oxidation were equal to 51%, 39% and 5% respectively under the 0.4 V voltage in 60 min. The effect of various parameters was studied and the highest degradation percentage of 2,5-dichlorophenol was obtained at pH 6.0, the initial 2,5-dichlorophenol concentration of 7.0 mg L-1 and applied potential of 1.2 V. Manuscript profile

In this work, for the first time, a new and effective bulk modified carbon paste electrode (CPE) was prepared by TiO2 nanoparticles and chitosan and then Ni2+ ions were incorporated to this electrode by immersion of the modified electrode in nickel chloride solution. The values of electron transfer coefficient, charge-transfer rate constant and electrode surface coverage for Ni(II)/Ni(III) redox couple of the TiO2/chitosan modified carbon paste electrode (Ni-TiO2/CHIT/CPE) were found to be 0.66, 3.28 × 10-1 s-1 and 5.14 × 10-8 mol cm-2, respectively. The prepared Ni-TiO2/CHIT/CPE material was characterized by scanning electron microscopy and X‐ray diffractometry. The electrochemical behaviour of the Ni-TiO2/CHIT/CPE towards oxidation of formaldehyde was evaluated and proved. The effects of various factors on the efficiency of electrocatalytic oxidation of formaldehyde were optimized. Under the optimized condition, a calibration curve was obtained in the linear dynamic range of 2.80 × 10-4 to 2.50 × 10-2 mol L-1 with detection limit of 7.14 × 10-5 mol L-1 (3σ/slope) for formaldehyde determination. Also, the method was successfully applied for formaldehyde measurement in the real sample. Manuscript profile