Simulation Study Of Adsorption Of Water Contaminants On Doped Carbon Nanomaterials

Carbon nanomaterials have many advantages such as small size,high carrier mobility,good conductivity,strong adsorption and desorption ability,and they are potential adsorption materials in wastewater treatment.The advantage of large specific surface area makes CNTs and graphene stand out.However,the intrinsic CNTs and intrinsic graphene have chemical stability,so they are not suitable for applying in adsorbents or sensors.To apply the excellent characteristics of CNTs and graphene in wastewater treatment effectively,it is necessary to make proper modifications on CNTs and graphene.The researches on the application of doped CNTs and doped graphene in wastewater treatment are not sufficient now,and the effect of different doping elements on the adsorption of water pollutants by CNTs and graphene is not yet clear.First principles based on density functional theory are used to study the effect of doping modification on the adsorption between carbon nanomaterials and various particles in water pollutants.Compared with intrinsic graphene,the adsorption distance between defective graphene and Cu²⁺/Zn²⁺ions is significantly reduced,and the adsorption energy,charge transfer and charge density are significantly increased,which indicates that stable chemical adsorption is formed between defective graphene and Cu²⁺/Zn²⁺ions.Intrinsic graphene can adsorb SO₄^2-ions but it cannot stably co-adsorb SO₄^2-and Cu²⁺/Ca²⁺/Zn²⁺/Mg²⁺ions.Al doped graphene can co-adsorb SO₄^2-and Cu²⁺/Ca²⁺/Zn²⁺/Mg²⁺ion effectively,among which its adsorption on SO₄^2-and Cu²⁺ions is the most stable.B doped graphene can form stable chemical adsorption with F^-ions,but it can only form physical adsorption with HF molecules.While Al doped graphene can adsorb both F^-ions and HF molecule stably,and it is highly sensitive to F^-ions.Both doping Mn atoms and intrducing defects on CNTs can improve the adsorption between CNTs and NH₃ molecules.Mn doped defective CNTs can adsorb NH₃ molecule stably.The above studies indicate that doped carbon nanotubes and doped graphene are expected to be used in the treatment of water pollutants.The research provides a solid theoretical basis for designing new-type adsorbents and sensors.Figure 24;Table 10;Reference 109...