Fabrication of g-C3N4/Au/CdZnS Z-scheme photocatalyst to enhance photocatalysis performance

Abstract

In this study, a sandwich-structured C₃N₄/Au/CdZnS photocatalyst with Au nanoparticles sandwiched between C₃N₄ and CdZnS was fabricated. The results showed that there was a 6.3 mmol g⁻¹ increase of hydrogen production for C₃N₄/Au/CdZnS photocatalyst compared to C₃N₄/CdZnS in 4 h. The photoinduced I–t curve, electrochemical impedance spectrum (EIS), photogenerated electron lifetime and photoluminescence spectra showed that the photocatalytic ability of the composite was enhanced by anchoring Au as the electron transfer mediator between C₃N₄ and CdZnS through the Z-scheme charge-carrier transfer mechanism. Au functioned as an electron transition mediator, which could induce a combination between photogenerated electrons and holes in the CdZnS and C₃N₄, respectively. These photogenerated holes of CdZnS can be involved in the S²⁻/SO₃²⁻ oxidation process and the electrons from the C₃N₄ surface might be involved in the water to hydrogen reduction reaction, thus enhancing the photocatalysis performance of C₃N₄/Au/CdZnS photocatalyst.