Synthesis, characterization and adsorption capability of CdO microstructure for Congo red from aqueous solution

Cadmium oxide rhombus-shaped nanostructure was synthesized using hydrothermal process followed by heating treatment. Clearly, X-ray diffraction pattern demonstrated the formation of CdO crystalline phase. Scanning electron microscopy (SEM) showed that the obtained rhombus-like structure is composed of nanoparticles with the average size of 29 nm. In addition, we evaluated adsorption of organic dye i.e. Congo red from water using the prepared CdO rhombus like microstructure. UV-visible absorption spectroscopy was used to record the adsorption behavior. It was found that the removal process is performed via electrostatic absorption mechanism. The maximum adsorption capacity of CdO rhombus structures (0.01 g) for Congo Red (CR) in the concentration range (5-50 mg L -1 ) studied, as calculated from the Langmuir isotherm model at 25 ?C and neutral pH, was found to be 41.20 mg g ?1 .