Photoreduction of 4-Nitrophenol to 4-Aminophenol Using CdS Nanorods

In this study CdS nanorods (NR), of 46.6 nm average length and diameter ≥3.30 nm (TEM), derived from cadmium(II) dibenzylcarbamodithioate have been used as a visible light driven photocatalyst for the transformation of environmentally detrimental 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) of pharmaceutical significance. As prepared CdS-NR were characterized by powder X-ray diffraction (PXRD), transmission electron microscopy (TEM), selected area electron diffraction technique (SAED), fourier transmission infrared spectroscopy (FTIR), energy dispersive X-ray spectroscopy (EDS), steady-state and time resolved photoluminesce (PL) and UV-visible spectroscopy (band gap of 2.4 eV). PXRD results revealed that CdS-NR exhibit pure hexagonal character. The photoluminescence and time-resolved PL have confirmed the low electron–hole recombination rate in CdS-NR than the bulk CdS. The transformation of 4-NP to 4-AP on CdS-NR follows pseudo-first order kinetics with a rate constant 0.202 min−1 and turnover frequency (TOF) 6.06 h−1.