Table 1.

Summary of the advantages and disadvantages of different synthesis methods

Synthesis method	Advantages	Disadvantages
Laser ablation	Simple experimental setup Can produce particles with different size by changing experimental parameters	Low yield
Arc discharge	Can be obtained from the by-products from purification of carbon nanotubes	Arc-discharged soot contains impurities that are to remove Expensive equipment
Electrochemical approach	Low cost High output Easy manipulation	Doping with heteroatoms is difficult
Chemical oxidation	Requires inexpensive equipment Large-scale production	Tedious steps Toxic reagents Requires strong acid/base
Hydrothermal	Low cost Easy to manipulate parameters such as temperature, time, and pressure of vessel	Long synthesis duration
Pyrolysis of precursors	Simple procedure Short synthesis duration	Difficult to achieve high temperatures for aqueous reaction using domestic microwave oven Simple pyrolysis is difficult to be scaled up due to uneven heating Broad size distribution
Reverse micelles	Can be carry out in room temperature	Complicated steps involved
Supported template	Uniform particle sizes	Complicated steps involved Requires additional passivation steps Difficult to purify