PtAu/graphene nanocomposites (Pt:Au=1:1) were synthesized at room temperature. First,0.249 mL H2PtCl6 (7.53 mg Pt mL-1 H2O) and 0.420 mL HAuCl4 (4.46 mg Au mL-1 H2O) were added into 200 mL of deionized H2O under vigorous stirring. A 150 mg of PDDA solution (35wt. % in H2O solution) was added to capture the PtCl6 2- and AuCl4- ions within the long chains of PDDA via the electrostatic interaction.1 Then, a strong reducer NaBH4 (22.5 mg dissolved in 3.5 mL H2O) was added all at once and the reaction lasted for 5 min under vigorous stirring.During this process, the color of the solution changed from light yellow to brown, and PtAu alloy NPs were obtained. After that, 15 mg as-prepared graphene nanosheets were added into the PtAu solution above. Then, 100 mg KNO3 was used to promote PtAu NPs to load on graphene nanosheets.2
请问一下帅哥,这样得到的合金纳米粒子表面是不是带正电荷啊?