Recent Progress of Graphene-Based Photoelectrode Materials for Dye-Sensitized Solar Cells

Figure 4

SEM images of lyophilized GO solution and three typical GO hydrogels: (a) GO solution, (b) GO/PVP hydrogel with 1 mg mL⁻¹ PVP, (c) GO/PDDA hydrogel with 0.1 mg mL⁻¹ PDDA, and (d) GO/Ca²⁺ hydrogel with 9 mM Ca²⁺. , and scale [111].

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