Surfactant-Free Microwave-Assisted Synthesis of Fe-Doped ZnO Nanostars as Photocatalyst for Degradation of Tropaeolin O in Water under Visible Light

Table 1

Factors and levels in the optimization of the photocatalytic degradation of Tropaeolin O through Taguchi analysis.

Level	Factor
	Catalyst loading (mg)	Temperature (°C)	Light distance (cm)	Initial pH	Irradiation time (h)
1	7.5	30	0	5	1.5
2	15.0	40	5	7	2.0
3	22.5	50	10	9	2.5
4	30.0	60	15	11	3.0