لخّصلي

The properties of activated carbon are determined by several factors during the preparation phase. Here is a summary of these factors:

1. 
   

   Raw materials: The choice of organic materials used as precursors for activated carbon greatly influences its properties. The raw materials should have a high carbon content, low inorganic matter or ash content, high density, sufficient volatile content, stability, low degradation during storage, and economic feasibility.

   
   


2. 
   

   Surface area and pore size distribution: The temperature and activating agent used during the preparation process are crucial parameters that affect the physicochemical properties of activated carbon. Higher temperatures promote the decomposition of carbonaceous species and increase crystallinity. However, excessive crystallinity can lead to a reduction in surface area.

   
   


3. 
   

   Degree of graphitization: High-temperature annealing promotes graphitization, which enhances the conductivity of the carbon matrix. However, excessive graphitization can deplete the heteroatom content and reduce carrier concentration.

   
   


4. 
   

   Heteroatom content: The presence of heteroatoms in activated carbon facilitates the adsorption of ions on its surface. However, excessive doping of heteroatoms can negatively affect the conductivity within the carbon network.

   
   


5. 
   

   Surface concentration of heteroatoms: Surfactant species can improve the wettability of the carbon matrix. To achieve the desired wettability, an adequate amount of heteroatoms is required.

   
   


6. 
   

   Type of functional groups: Functionalities introduced by heteroatoms can enhance reactivity and conductivity in the carbon matrix. For example, pyridinic N acts as a Lewis base, while graphitic N promotes conductivity.

   
   


7. 
   

   Activation time: The duration of the activation process significantly impacts the carbonation and final properties of activated carbon. Longer activation times increase the BET surface area but decrease the percentage yield of activated carbon due to the volatilization of organic matter during carbonization.

   
   


8. 
   

   Activation temperature: Along with activation time, the activation temperature plays a crucial role in determining the BET surface area and yield of carbonized products. Higher activation temperatures lead to an improvement in the BET surface area by creating new pores and enlarging existing ones through the release of volatile substances. However, increasing the activation temperature also reduces the yield of activated carbon due to the loss of volatile matter.

   
   

By carefully controlling these parameters, high-performance activated carbon with desired properties can be produced.