The influence of the sacrificial agent nature on transformations of the Zn(OH)2/Cd0.3Zn0.7S photocatalyst during hydrogen production under visible light

摘要

Photocatalysts based on zinc hydroxide and a solid solution of CdS and ZnS were prepared via the precipitation method and used for photocatalytic hydrogen production from aqueous solutions of inorganic (Na _(2) S/Na _(2) SO _(3) ) and organic (ethanol) sacrificial agents. The photocatalysts were tested in cyclic experiments for hydrogen evolution and studied using X-ray diffraction (XRD), UV-Vis diffuse reflectance spectroscopy, high-resolution transmission electron microscopy (HRTEM), energy-dispersive X-ray spectroscopy (EDX), and X-ray photoelectron spectroscopy (XPS) techniques. Different transformations of the β-Zn(OH) _(2) co-catalyst were observed in the presence of inorganic and organic sacrificial agents; namely, ZnS was formed in Na _(2) S/Na _(2) SO _(3) solution, whereas the formation of ε-Zn(OH) _(2) was detected in solution with ethanol. The composite Zn(OH) _(2) /Cd _(1? x ) Zn _( x ) S photocatalysts have great potential in various photocatalysis processes ( e.g. , hydrogen production, CO _(2) reduction, and the oxidation of organic contaminants) under visible light.