Photocatalytic reduction of 4-nitrophenol to 4-aminophenol over CdS/MgAl layered double hydroxide catalysts under UV irradiation

CdS-hydrotalcite-type compounds were synthesized in one step by the co-precipitation method. Structural, textural, spectroscopic and morphological properties were evaluated by X-ray diffraction (XRD), BET analysis, Fourier transform infrared spectroscopy (FTIR) and SEM/EDS analysis. XRD patterns showed that the CdS/MgAl materials have a wurtzite type hexagonal structure characteristic of CdS and the MgAl material presented an adjustment to a hexagonal lattice with rhombohedral symmetry, the surface area showed that CdS material presents the lowest surface area of 4 m(2)/g, FTIR exhibited the presence of the vibrations of CO3 (2-) ions in the sheet and by elemental mapping, the dispersion of the metallic particles and sulfur in the lamellar structure is confirmed. The photocatalytic evaluation under UV irradiation of the synthesized solids was evaluated in the reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) using Na2SO3 as sacrificial agent showing that CdS-hydrotalcite-type compounds are very promising catalyst for photoreduction reactions.