Photocatalytic Evaluation of the ZrO2:Zn5(OH)6(CO3)2 Composite for the H2 Production via Water Splitting

The present work studies the effect of zirconium dioxide addition in hydrozincite (Zn-5(OH6)(CO3)(2)). The composites samples shows an efficient photocatalytic activity for H-2 production under UV light irradiation and employing methanol as a sacrificial reagent. The composites were synthesized in one-pot method, dried to 100 degrees C and characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), UV-Vis diffuse reflectance spectroscopy (UV-Vis DRS), X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM), elemental mapping by SEM and transmission electron microscopy (TEM). The most active composite with 3 mol% of ZrO2 exhibited a H-2 production of 1908 mu mol g(-1) h(-1) and an apparent quantum yield (AQY) of 41%. The photoactivity is attributed to the formation of heterojunctions, it is confirmed by the characterization techniques. The heterojunctions result in a synergic effect, the hydrozincite provides a wide surface area for electron transfer while the zirconium dioxide inhibits the recombination through the photogenerated holes attraction.