Electrochemical Detection of Arsenic(lll) Using Iridium-Implanted Boron-Doped Diamond Electrodes

摘要

Indium-modified,boron-doped diamond electrodes fabricated by an ion implantation method have been developed for electrochemical detection of arsenite (As(III)).Ir~+ ions were implanted with an energy of 800 keV and a dose of 10~(15) ion cm~(-2).An annealing treatment at 850 deg C for 45 min in H_2 plasma (80 Torr) was required to rearrange metastable diamond produced by an implantation process.Characterization was investigated by SEM,AFM,Raman,and X-ray photoelectron spectroscopy.Cyclic voltammetry and flow injection analysis with am-perometric detection were used to study the electrochemical reaction.The electrodes exhibited high catalytic activity toward As(III) oxidation with the detection limit (S/N = 3),sensitivity,and linearity of 20 nM (1.5 ppb),93 nA mu M~(-1) cm~(-2),and 0.999,respectively.The precision for 10 replicate determinations of 50 mu M As(III) was 4.56% relative standard deviation.The advantageous properties of the electrodes were its inherent stability with a very low background current.The electrode was applicable for analysis of spiked arsenic in tap water containing a significant amount of various ion elements.The results indicate that the metal-implanted method could be promising for controlling the electrochemical properties of diamond electrodes.