Continuous microwave flow synthesis and characterization of nanosized tin oxide

• Continuous microwave flow synthesis technique was used to prepare nanosized SnO2.
• Bandgap of SnO2 decreased with increase in microwave power.
• Degree of crystallinity of SnO2 improved with increase in microwave power.

We report here the effect of microwave power on the physicochemical and photocatalytic properties of nano-crystalline tin oxide (SnO2) synthesized by using a continuous microwave flow synthesis (CMFS) process. The obtained nanoparticles (Nps) were characterized by using TEM, XRD, FTIR, BET, UV–vis and PL spectra. TEM characterizations revealed that the SnO2 Nps were agglomerated spheroids. A red shift in energy bandgap (Eg) and a reduction in the photoluminescence (PL) peak intensity were observed on increasing the microwave power. Photocatalytic study confirmed that the synthesized SnO2 Nps were efficient in degrading methylene blue (MB) dye. SnO2 NPs with decreased Eg have potential to be used in solar cell windows, opto-electronic (UV) devices, UV photo-detector and gas sensing applications.