Microwave Assisted Synthesis of ZnO Nanoparticles: Effect of Precursor Reagents, Temperature, Irradiation Time, and Additives on Nano-ZnO Morphology Development

Table 1

Experimental conditions employed during microwave assisted synthesis of ZnO.

Synthesis code	Experimental conditions (irradiation time^a, temperature, and microwave power)	Zn precursor, 15 mL; 1.6 mol L^−1	Base, 4 mL 3.2 mol L^−1	Yield, %	Average crystallite size, nm	Average particle size^h,; µm
MW-1	20 min, 80°C, 600 W	Zn(NO3)2 6H2O	NaOH	N.A	N.A	N.A
MW-2	20 min, 100°C, 600 W	Zn(NO3)2 6H2O	NaOH	N.A	N.A	0.413 (W^i); 0.088 (L^j)
MW-3	20 min, 120°C, 600 W	Zn(NO3)2 6H2O	NaOH	93.51	8.05	1.116 (W); 3.099 (L)
MW-4	20 min, 140°C, 600 W	Zn(NO3)2 6H2O	NaOH	89.71	8.25	1.927 (W); 6.512 (L)
MW-5^b	20 min, 140°C, 600 W	Zn(NO3)2 6H2O	NaOH	99.31	6.41	1.534 (W); 3.577 (L)
MW-6^c	20 min, 140°C, 600 W	Zn(NO3)2 6H2O	NaOH	87.02	6.41	0.128 (W); 0.192 (L)
MW-7^d	20 min, 140°C, 600 W	Zn(NO3)2 6H2O	NaOH	92.30	6.31	0.123 (W); 0.059 (L)
MW-8^e	20 min, 140°C, 600 W	Zn(NO3)2 6H2O	NaOH	82.72	7.53	0.394 (W); 0.311 (L)
MW-9^f	20 min, 140°C, 600 W	Zn(NO3)2 6H2O	NaOH	89,73	8.22	1.308 (W); 4.092 (L)
MW-10	0 min, 140°C, 600 W	Zn(NO3)2 6H2O	NaOH	N.A	8.25	N.A
MW-11	5 min, 140°C, 600 W	Zn(NO3)2 6H2O	NaOH	91.17	8.22	1.467 (W); 3.256 (L)
MW-12	10 min, 140°C, 600 W	Zn(NO3)2 6H2O	NaOH	92.23	8.23	1.006 (W); 2.493 (L)
MW-13	20 min, 140°C, 300 W	Zn(NO3)2 6H2O	NaOH	81.40	8.26	1.487 (W); 3.924 (L)
MW-14	20 min, 140°C, 1200 W	Zn(NO3)2 6H2O	NaOH	90.35	8.40	1.351 (W); 3.154 (L)
MW-15	20 min, 140°C, 600 W	Zn(NO3)2 6H2O	KOH	87.00	7.77	0.870 (W); 2.375 (L)
MW-16	20 min, 140°C, 600 W	Zn(NO3)2 6H2O	KOH^g	N.A	7.81	0.220 (W); 1.063 (L)
MW-17	20 min, 140°C, 600 W	Zn(NO3)2 6H2O	NH4OH	N.A	7.54	1.689 (W); 4.673 (L)
MW-18	20 min, 100°C, 600 W	Zn(CH3COO)2 2H2O	NaOH	N.A	8.05	3.716 (W); 3.662 (L)
MW-19	20 min, 120°C, 600 W	Zn(CH3COO)2 2H2O	NaOH	N.A	7.97	3.128 (W); 3.951 (L)
MW-20	20 min, 140°C, 600 W	Zn(CH3COO)2 2H2O	NaOH	N.A	8.15	1.656 (W); 1.735 (L)
MW-21	20 min, 140°C, 600 W	ZnCl2	NaOH	N.A	N.A	N.A

 ^aAn initial 10 min period required to reach the target temperature must be considered in all cases.
^bSolid product was isolated by centrifugation. The product was not washed.
^cChange in the addition order.
^d0.24 g of sodium di-2-ethylhexyl-sulfosuccinate dissolved in water were added before base addition.
^e0.50 g of sodium di-2-ethylhexyl-sulfosuccinate dissolved in water were added before base addition.
^f1 g of ethylene glycol dissolved in water was added before base addition.
^g13 mL of base were added instead of 4 mL.
^hCalculated from SEM images employing ImageJ Software.
ⁱAverage width of the rod-like particles.
^jAverage length of the rod-like particles.
N.A: not available.