Table 4.

A comparative study of ZnO NPs synthesis by different methods with this work.

Synthesized method		Particle size (nm)	Atomic (%)		Band gap (eV)	Reference
			Zn	O
Sol-gel		84.98	55.38	44.62	–	30
Ball Milling		13.07	45.15	54.85	3.39	31
Hydrothermal		32.49	–	–	3:29	32
Green Synthesis		26.04	51.38	48.21	3.69	33
Spray-Pyrolysis		14.5	–	–	3.11	34
Chemical precipitation	MEA (15 ml)	34.26	38.09	61.91	3.33	This work
	MEA (7.2 ml)	36.14	37.16	62.84	3.33
	MEA (3.6 ml)	38.18	22.12	47.29	3.33