Green and Cost-Effective Synthesis of Tin Oxide Nanoparticles: A Review on the Synthesis Methodologies, Mechanism of Formation, and Their Potential Applications

Table 2 Biomolecules or other green sources used for the synthesis of SnO₂ NPs with their shape, size, and brief experimental condition

Biomolecules	Precursors	Synthesis conditions	Shape	Size	Applications	Ref
Ascorbic acid (Asc)	SnCl₂·2H₂O	Reaction: 80 °C , 8 h Calcination: 300 °C , 2 h	Spherical	30 nm	Bodyweight effect on neonatal mice	[75]
Arginine	SnCl₂·2H₂O	Irradiation: thirty 10 s 300 W shots on microwave oven Drying: 70 °C	Spherical	4–5 nm	Efficient photocatalyst in the degradation of methylene blue dye	[81]
Aspartic acid and glutamic acid	SnCl₂·2H₂O	Irradiation: thirty 10 s 300 W shots on microwave oven Drying: 70 °C	Spherical	1.6–2.6 nm	Excellent photocatalyst against Rose Bengal and Eosin Y	[82]
Glycine	SnCl₂·2H₂O, glycine	Reaction: 100 °C , 4 h Drying: 60 °C, Calcination: 200–600 °C , 2 h	Spherical	6–33 nm	–	[83]
L-lysine	SnCl₂·2H₂O	Reaction: 100 °C , 3 h Drying: 60 °C Calcination: 200 -500 °C , 2 h	Spherical	4–17 nm	Exceptional photocatalyst against triphenylmethane dyes An excellent catalyst for the reduction of 4-nitrophenol to 4-aminophenol	[84]
Tyrosine	SnCl₂·2H₂O	Reaction: 100 °C , 4 h Drying: 60 °C Calcination: 500 °C , 2 h	Tetragonal	15–20 nm	Photocatalytic activity against Violet 4 BSN dye	[85]
Sugarcane juice	SnCl₂·2H₂O	Irradiation: thirty 10-s shots on microwave oven Calcination: 200 °C	Spherical	2.5–4.5 nm (TEM)	An excellent catalyst for the reduction of p-nitrophenol Efficient photocatalyst for degradation of methylene blue and Rose Bengal	[86]