Visible light photocatalytic reduction of 4-Nitrophenol using CdS in the presence of Na2SO3

The photocatalytic properties of CdS semiconductors were investigated for the photoreduction of 4-Nitrophenol with Na2SO3 under blue light irradiation. The materials were synthesized by co-precipitation method in ethylenediamine–water solution and their structural and optical properties were characterized by X-ray diffraction, UV–vis spectroscopy and nitrogen physisorption. The CdS semiconductor prepared at higher EN contents (90 vol.%) presented the highest photocatalytic activity for the reduction of 4-Nitrophenol to 4-Aminophenol. Their photo-efficiency enhancement is attributed to the quantum confinement effect caused by the small particle size (∼15 nm).