γ-Nax Co2 O4 oxide thermoelectric material was synthesized by polyethylene glycol 400 (PEG400)modified citrate sol-gel method.And the effects of PEG400 on the formation ofγ-Nax Co2 O4 crystals were studied.Through XRD and FESEM analysis, the influence of PEG400 content on phase composition and morphology of theγ-Nax Co2 O4 product was discussed and the process-ing parameters were optimized.Results show that the addition of PEG400 generates significant influence on the phase composition and morphology of the sample.Single phaseγ-Nax Co2 O4 crystals can be formed with 1% PEG400 content (volume fraction), Na+/Co2+ molar ratio of 0.85-0.9,and calcination temperature of 800 ℃.The obtained crystals with certain orientation were near parallel plate-like particles and the particle distribution takes on a three dimensional network structure,indicating thatγ-Nax Co2 O4 forms a more stable gel structure after the addition of PEG400.%采用聚乙二醇400（PEG400）改进的柠檬酸盐溶胶-凝胶法制备氧化物热电材料γ-Nax Co2 O4，通过 XRD 和 FESEM 分析，研究了 PEG400添加量对γ-Nax Co2 O4产物的相组成和形貌的影响，优化了 PEG400改进柠檬酸盐溶胶-凝胶法制备γ-Nax Co2 O4的工艺参数。结果显示，PEG400的添加对样品的相组成和形貌均产生了明显影响。当 PEG400添加量（体积分数）为1％，n（Na＋）／n（Co2＋）为0．85～0．9，煅烧温度为800℃时，得到了单相γ-Nax Co2 O4晶体。当 PEG400添加量（体积分数）为1％时，γ-Nax Co2 O4晶体为近似平行排列的片状颗粒，具有一定的取向性，颗粒分布呈现出一种三维网状结构，表明添加PEG400后，γ-Nax Co2 O4形成了更稳固的凝胶结构。
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