Table 1.

The advantages and disadvantages of various preparation methods of COS.

Preparation Methods of COS	Advantages	Disadvantages
Chemical degradation	Simple to handle	Difficult to separate and purify the products
Physical degradation	Easy purification and little contamination	Low productivity
Enzymatic degradation	Easy accessibility, no additional product modifications	High cost but low availability
Electrochemical degradation	Easy to operate and contamination-free	Short electrode life and easy to fail