*2.1.3 Microwave-hydrothermal synthesis*

Microwave-hydrothermal (MH) synthesis is a modified synthesis method based on the hydrolysis technique. The starting materialis very equivalent to the hydrothermal synthesis starting material, but Na2CO3 is frequently utlized as the mineralizer in conjunction with KOH [2, 3] to gained perovskite BiFeO3 crystals. After transferring the starting material into a Teflon autoclave, it is placed in a microwave oven for the hydrothermal reaction, which is heated at 160-230°C for 30–60 minutes [2, 3, 51, 52]. The particle size produced by MH techniques could be as minimal as 10-50 nm [2] that is smaller than the average particle size produced by hydrothermal process. Furthermore, MH has been utilized to create bismuth ferrite nanotubes with an average size of 50–200 nm and a low bandgap of 2.1 eV [3].
