Li2Si2O5 Nano-brush Coated Carbon Cloth as a Potential Solution for Wastewater Treatment

Li2Si2O5 nano-brush coated carbon cloth was synthesized using a hydrothermal method with lithium hydroxide and tetraethyl orthosilicate as the resource chemicals. Its adsorption capabilities for Mn2+, Cu2+ and Ni2+ ions were demonstrated for wastewater treatments, and their corresponding maximum adsorption capacities were 325.60, 314.76 and 270.15 mg/g at 298 K, respectively. Brush-like and highly uniformly Li2Si2O5 nanorods with an average diameter of ∼60 nm were uniformly synthesized onto the carbon cloth. Adsorption experiments showed that the adsorption behaviors for selected heavy metal ions followed both a pseudo-second-order model and a Langmuir isothermal model, indicating that the adsorption process was a monolayer and chemical adsorption one. The key adsorption mechanisms were identified as surface complexation between heavy metal ions and hydroxyl groups and ion-exchanges between heavy metal ions and lithium ions. These brush-like nanorods have advantages of effective adsorption of heavy metal ions in wastewater due to their widely exposed active sites and effective ion diffusion and transport.