Self-assembled CuS porous grade sub-nanoflowers as efficient nano-adsorbents for adsorption/self-deposition characteristics research

In recent decades, growing population and industrial development have led to releasing huge amounts of highly toxic chemical pollutants into the environment globally. Several approaches to handling the removal of contaminants from wastewater for environmental remediation, including biological, chemical, physical, and advanced oxidation processes have been employed. Among them, using nano-adsorbents as a tool for effectively removing organic contaminants represents a promising strategy in sewage purification field. More importantly, the nano-adsorbents with auto-deposition property can greatly improve the efficiency of sewage treatment. Therefore, the developing of environment friendly nano-adsorbents is thus an important issue to remove organic contaminants in water via simply adsorbing. Here in this work, porous flower-like copper sulfide (CuS) grade sub-nanomaterials are successfully fabricated by simply mixing two inorganic salts. Furthermore, the as-prepared nano-adsorbents with auto-deposition property can create a super adsorption capability for organic contaminants in wastewater. We further study the adsorption/auto-deposition characteristics of porous flower-like CuS grade sub-nanomaterials systematically by using various organic dyes (methyl blue, crystal violet, lemon yellow, sunset yellow and amaranth) as target molecules. For instance, in a typical procedure, 0.8-mg methyl blue can be removed 100% via adding 10-mg porous flower-like CuS grade sub-nanomaterials sample in 30 min. Therefore, the adsorption efficiency can be enhanced by 55% and 26% in comparison with the adsorption efficiency of CuS micro pompons and micron particles, respectively. Additionally, the porous flower-like CuS grade sub-nanomaterials can self-deposite on the bottom of the solution within 3 h after adsorption has finished, and the deposition efficiency can be improved by 95% and 3.17 times in comparison with the deposition efficiency of CuS micro pompons and micron particles, respectively. Comparing with micron particles, the unique self-depositing characteristics of porous flower-like grade sub-nanomaterials are attributed to larger specific surface area, greater porosity and stronger electrostatic adsorption capacity. Remarkably, this work provides an effective method of effectively removing various organic dyes from wastewater.