One-step separation of tin from e-waste by a chemical vapor transport process (CVT): Preparation of nano-SnO2

•Tin in e-waste was efficiently separated and recycled by a novel two-stage CVT process.•The conversion of sn-SnO(g)-SnO2 during staged oxidation was revealed.•The inhibition mechanism of O2 content on SnO disproportionation was revealed.•Tetragonal nano-SnO2 with a crystallinity of 99.9% was obtained from e-waste.