Table 2.

Methods and conditions of etching

MAX Phase	Etching solution and condition	Resulting product	Characteristic	Reference
Ti3AlC2 powder	50%HF, room temperature, 2 h	Ti3C2	High toxicity	[23]
Ti3AlC2 powder	30%HF, room temperature, 5 h 10%HF, room temperature, 18 h 5%HF, room temperature, 24 h	Ti3C2Tx	Low toxicity	[31]
Ti3AlC2 powder	1 M NH4HF2, 60℃,8 h	Ti3C2	Non-toxic, monolayer MXene	[30, 35]
Ti3AlC2 powder	LiF + 6 M HCl, 35℃,24 h	Ti3C2Tx	Non-toxic, monolayer MXene	[24]
Ti3AlC2 powder	LiF + 9 M HCl, room temperature,24 h	Ti3C2Tx	Non-toxic, monolayer MXene	[31]
Ti3AlC2 powder	ZnCl2, 550℃	Ti2CCl2 Ti3C2Cl2	Non-toxic, Need not MAX Phase	[36]
Zr3Al3C5 powder (not MAXphase)	50%HF, room temperature	Zr3C2	Non-toxic, Need not MAX Phase	[37]