Investigation of the influence for S-ions incorporated into the Ag₂ZnSnSe₄ photoelectrodes on their light-enhanced activities in aqueous salt-water solution

Background: Large-scale application in solar salt-water splitting is an important way to reduce the influence of environmental problem without any decrease in the usage of energy. To develop the photoelectrochemical (PEC) salt-water splitting is thus a promising way for further industrial application. Methods: The Ag₂ZnSnSe₄ (AZTSe) and their S-ions incorporating samples were produced by the post selenization/sulfurization of Ag/Sn/Zn sandwich metal precursors with the suitable amount of sulfur + selenium powder mixtures at 410 ℃ for 90 min under nitrogen atmosphere. The PEC tests using samples as photoelectrode were then carried out. Significant findings: The maximum light-enhanced activity of pristine AZTSe and their S-ions incorporated samples was 3.65 and 2.37 mA/cm² as the applied voltage of 1.23 V vs. RHE (relative hydrogen electrode) in a 0.5 M sodium chloride electrolyte, respectively. Electrochemical impedance and intensity-modulated photocurrent spectra of samples represented that the S-ions incorporated into AZTSe sample could reduce the photo-corrosion reaction on sample surface because of the decrease in the number of light-induced holes occupied on sample surface. Our report proposed the systemic evaluation on the influence of S-ions incorporated into AZTSe sample for light-enhanced salt-water splitting.