Table 1. Comparison of the microwave assisted methods with other physical methods and summary of their morphological size.

Method of synthesis AgNPs	Size of the AgNPs	Morphology of the AgNPs	References
Microwave annealing	< 50 nm	Spherical shape	[40]
Thermal annealing	5–45 nm; 7–20 nm	Spherical shape	[41, 42]
Ion irradiation	5–25 nm; <10 nm	Almost spherical shape	[43,44]
UV irradiation	<50 nm	Spherical or ellipsoidal or triangular	[45]
γ-irradiation	<20nm; <30nm	Mostly spherical <10nm	[46,47]