Table 1.

Modified procedures of various studies taken as reference for our study.

Sl No.	Plant/fungi/bacteria (Concentration),	Filtering process/pre heating	Working temperature and condition	References
1	Brassica oleracea L. var. Italic (8g in 80 ml)	At 70 °C for 20 min	Heated at 70 °C for 20 min + centrifuged at 6000 rpm for 20 min + dried at 80 °C for 6 h + calcinated at 450 °C	[50]
2	Deverra tortuosa (crude extract of 25 ml)	At 60–80 °C	Heated at 60 °C overnight + paste collected and heated at 400 °C for 2 h	[51]
3	Euphorbia petiolata (50g in 500 ml)	At 80 °C for 30 min	Heated at 80 °C for 2 h + centrifuged at 6000 rpm + annealing at 400 °C for 2 h	[52]
4	Punica granatum L. (40g)	At 40 °C at pH 3 and filtered with Whatman filter paper (0.22 m)	Heated at 80 °C + centrifuged at 1000 rpm for 10 min annealing at 400 °C and 500 °C	[53]
5	Mussaenda frondosa (1:10)	At 100 °C for 4 h	Stirring at 450–500 rpm + mix heated at 400 °C for 10–30 min in magnetic stirrer	[54]
6	Eucalyptus globulus Labill (20g in 100 ml)	At 60 °C in oven and cooled to room temperature	Centrifuged at 5000 rpm for 1 h + calcined at 400 °C for 2 h	[55]