A facial method to synthesize Ni(OH)2 nanosheets for improving the adsorption properties of Congo red in aqueous solution

A new and facial (low temperature and low cost) method for a direct synthesis of the stable and crystalline phase pure Ni(OH)2 nanosheets was developed using cationic surfactant cetyltrimethylammonium bromide (CTAB). X-ray diffraction (XRD) analysis, Fourier transformed infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and high-resolution TEM (HRTEM) were used to examine the morphology and the microstructure of the obtained compound. The morphological study clearly revealed that obtained compounds appear in a flake-like nanosheet form with a typical length in the range of several hundreds of nanometers and a width in the range of several tens of nanometers. A possible formation mechanism is preliminary proposed for the formation of the nanostructure. The adsorption properties of Ni(OH)2 nanosheets were tested by the adsorption of azo dye Congo red (CR). The results show an excellent removal capacity for organic pollutant CR from the wastewater, making them a promising candidate for wastewater treatment.