To improve the synthesis of carbon nanotubes CNTs with increased yield and purity, while maintaining cost-effectiveness and environmental friendliness, we can consider the following approaches:1. Utilize a modified Chemical Vapor Deposition CVD method: The CVD process is widely used for synthesizing CNTs, but it can be optimized further. By using a catalyst with a higher activity and selectivity, such as bimetallic or trimetallic nanoparticles, the yield and purity of CNTs can be increased. Additionally, using a more efficient carbon source, such as bio-derived precursors, can reduce costs and environmental impact.2. Implement a Microwave-Assisted CVD method: Microwave-Assisted CVD can provide a more uniform heating process, leading to better control over the growth of CNTs. This method can potentially increase the yield and purity of CNTs while reducing energy consumption and overall costs.3. Explore Electrochemical Synthesis: Electrochemical synthesis is a green and cost-effective method for producing CNTs. By optimizing the electrolyte composition, electrode materials, and applied voltage, the yield and purity of CNTs can be improved.4. Employ Template-Assisted Synthesis: In this method, CNTs are grown within the pores of a template material, such as anodized aluminum oxide AAO or mesoporous silica. By controlling the pore size and structure of the template, the diameter and alignment of CNTs can be precisely controlled, resulting in higher purity and yield.5. Investigate Green Solvent-Assisted Synthesis: Using green solvents, such as water or ionic liquids, can reduce the environmental impact of CNT synthesis. By optimizing the solvent composition and reaction conditions, the yield and purity of CNTs can be improved.6. Optimize Purification Techniques: Developing more efficient purification techniques, such as selective oxidation, liquid-phase extraction, or density-gradient ultracentrifugation, can help remove impurities and increase the purity of CNTs.7. Scale-up and Automation: Scaling up the production process and automating the synthesis and purification steps can help reduce costs and increase the yield of CNTs.By exploring and optimizing these methods, the synthesis of carbon nanotubes can be improved to increase their yield and purity while maintaining cost-effectiveness and environmental friendliness.