Fig. 6From: Facile Synthesis of Hierarchical Tin Oxide Nanoflowers with Ultra-High Methanol Gas Sensing at Low Working TemperatureSEM images of the HTONF annealed at 300 °C (a, b); 400 °C (c, d); 500 °C (e, f); 600 °C (g, h); 700 °C (i, j)Back to article page