A photoelectrochemical sensor for lead ion through electrodeposition of PbS nanoparticles onto TiO2 nanotubes

•We develop a novel photoelectrochemical sensor for Pb2+ ion.•This method shows high selectivity, broad linear range, and low detection limit.•The approach has successfully applied for Pd2+ detection in tap water samples.

A selective and sensitive photoelectrochemical sensor for lead ion (Pb2+), which is based on the generated photocurrents of lead sulfide (PbS) nanoparticles under visible light irradiation, has been developed with theoretical and technical simplicity. The PbS nanoparticles are in-situ electrodeposited onto TiO2 nanotube arrays with the gradual addition of Pb2+. The present sensor shows high selectivity against other metal ions, broad linear range from 10−8 M to 10−5 M, and low detection limit of 0.39 nM (∼0.08 ppb), which is much lower than the standard of Pb2+ in drinking water formulated by World Health Organization (WHO). Thus, the strategy has been applied to successful detection of Pb2+ in tap and lake water samples. The results for determination of Pb2+ in lake water samples obtained by the present method and atomic adsorption spectroscopy (AAS) are consistent. However, the detection of Pb2+ in tap water samples has just been realized by the present method, but AAS cannot, because of its low detection limit.

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