Synthesis of nickel sulfide and nickel–iron sulfide nanoparticles from nickel dithiocarbamate complexes and their photocatalytic activities

Abstract

Abstract[Ni(dtc)2] (dtc = N‐(pyrrole‐2‐ylmethyl)‐N‐thiophenemethyldithiocarbamate (1), N‐methylferrocenyl‐N‐(2‐phenylethyl)dithiocarbamate (2), N‐furfuryl‐N‐methylferrocenyldithiocarbamate (3), and (N‐[pyrrole‐2‐ylmethyl]‐N‐thiophenemethyldithiocarbamato‐S,S′)(thiocyanato‐N)(triphenylphosphine)nickel(II) (4) complexes were prepared and characterized by elemental analysis, infrared, ultraviolet–visible, and nuclear magnetic resonance (1H and 13C) spectroscopies. The data were consistent with the formation of square planar nickel(II) complexes, which was confirmed by single‐crystal X‐ray diffraction studies on 2 and 4. Fe···Fe interactions exhibited by complex 2 led to supramolecular aggregation. The structure of 4 reveals intermolecular and intramolecular C‐H···Ni anagostic interactions. The anion‐sensing properties of 2 were studied with halide ions by cyclic voltammetry. It was observed that 2 acts as sensor for bromide. Complexes 1, 2, and 3, were utilized to prepare nickel sulfide, nickel–iron sulfide‐1, and nickel–iron sulfide‐2, respectively. The composition, structure, morphology, and optical properties of nickel sulfide and nickel–iron sulfides were examined using powder X‐ray diffraction, transmission electron microscopy, energy‐dispersive X‐ray spectroscopy, ultraviolet–visible, fluorescence, and infrared spectroscopy. Powder X‐ray diffraction patterns of nickel sulfide, nickel–iron sulfide‐1, and nickel–iron sulfide‐2 indicate the formation of orthorhombic Ni9S8, cubic NiFeS2, and cubic Ni2FeS4, respectively. The photocatalytic activities of as‐prepared nickel sulfide and nickel–iron sulfide‐1 nanoparticles were investigated for photodegradation of methylene blue and rhodamine‐B under ultraviolet irradiation. Nickel–iron sulfide‐1 nanoparticles show slightly higher photodegradation efficiency compared with the nickel sulfide nanoparticles.