The paper presents the morphological, structural and compositional properties of the sonochemically prepared ZnO-1.4wt% Graphene (Z-G) nanocomposites as a function of pH value of suspension varying from 8.5 to 14 and thermal annealing at 450°C in nitrogen or air ambient. The SEM analysis of the Z-G hybrids dried at 150°C in air has shown a nano-flower like nanostructure for a pH value of 14. The XRD analysis of dried Z-G hybrids revealed a crystallite size increase from 3.5 nm to 18.4 nm with pH increase, and this result was explained in terms of colloids zeta potential evolution with pH value. The Raman and EDS spectroscopy have shown a split of the G band (1575 cm⁻¹) of graphene into two bands (1575 cm⁻¹ and 1605 cm⁻¹), an increased height of D (1323 cm⁻¹) band, and an additional amount of carbon due to CO₂ absorption from the air, respectively. The carbon incorporation increased with the decrease of pH, and was associated with a hydrozincite phase, Zn₅(CO₃)₂(OH)₆. The formation of dried Z-G nanocomposite was clearly demonstrated only at a pH value equal to 14, where two ZnO Raman active bands at 314.9 cm⁻¹ and 428.2 cm⁻¹ appeared. This result may indicate the sensitivity of the Raman spectroscopy to the nanoflower-like nanostructure of dried Z-G hybrids prepared at pH=14. The thermal treatment of Z-G hybrids in N₂at 450°C has increased the number of ZnO Raman bands as a function of pH value, it has decreased the amount of additional carbon by conversion of hydrozincite to ZnO and preserved the graphene profile. The thermal treatment in air at 450°C has increased the crystalline symmetry and stoichiometry of the ZnO as revealed by high and narrow Raman band from 99 cm⁻¹ specific to Zn optical phonons, but it has severely affected the graphene profile in the Z-G hybrid, due to combustion of graphene in oxygen from the ambient.

中文翻译：

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声化学合成ZnO-石墨烯纳米杂化物及其表征

本文介绍了声化学制备的ZnO-1.4wt％石墨烯（ZG）纳米复合材料的形态，结构和组成特性，其与悬浮液pH值（从8.5到14）以及在氮或空气环境中在450°C下热退火的关系。对在150°C的空气中干燥的ZG杂种的SEM分析显示出pH为14的纳米花状纳米结构。干燥的ZG杂种的XRD分析表明，随着pH的增加，晶粒尺寸从3.5 nm增加到18.4 nm。 ，并根据胶体Zeta电位随pH值的变化来解释这一结果。拉曼光谱和EDS光谱显示石墨烯的G谱带（1575 cm ^-1）分为两个谱带（1575 cm ^-1和1605 cm ^-1），D的高度增加了（1323 cm^-1）谱带，以及由于从空气中吸收CO ₂而产生的额外碳量。碳的掺入随pH的降低而增加，并与水锌矿相Zn ₅（CO ₃）₂（OH）_6有关。仅在等于14的pH值下清楚地证明了干燥ZG纳米复合材料的形成，其中在314.9 cm ^-1和428.2 cm ^-1处出现两个ZnO拉曼活性带。该结果可以表明拉曼光谱对在pH ＝ 14下制备的干燥的ZG杂种的纳米花状纳米结构的敏感性。Z N杂化物在N _2中在450 ° C下的热处理ZnO拉曼能带的数量随pH值的增加而增加，通过水合锌矿转化为ZnO减少了额外的碳含量，并保留了石墨烯的分布。在450 ° C的空气中进行的热处理提高了ZnO的晶体对称性和化学计量，这是由Zn光学声子特有的99 cm ^-1的高和窄拉曼带所揭示的，但它严重影响了ZG杂化体中的石墨烯分布，是由于石墨烯在环境氧气中的燃烧。