An in situ photoelectrochemical determination of hydrogen sulfide through generation of CdS nanoclusters onto TiO2 nanotubes

A novel and facile photoelectrochemical method has been developed to detect H2S in water samples with high sensitivity and selectivity. The protocol is based on the photocurrent generated by CdS nanoclusters which are deposited onto TiO2 nanotubes exposing in CdSO4 solution with the gradual addition of Na2S, with low-cost, environment-friendly, theoretical and technical simplicity. The developed method shows a very broad linear range from 10(-8) M to 10(-3) M and a low detection limit of 0.31 nM (9.92 ppt), far lower than the ceiling value in drinking water provided by WHO. Furthermore, the present method has been applied for determination of H2S in water samples. The concentrations of H2S in water samples determined by the present method are in a good agreement with those monitored by traditional spectrophotometry.