摘要
通过溶胶-凝胶法合成了双钙钛矿型氧化物Sr_2Ni_(0.4)Co_(1.6)O_6、通过改性Hummers还原方法制备出薄层石墨烯,并制备单一物质和两者复合材料的双功能氧电极,用于测试其氧催化性能。采用XRD、EDS、SEM、FTIR对样品进行表征。结果显示:Sr_2Ni_(0.4)Co_(1.6)O_6均匀地分布于薄层石墨烯片层表面。电化学性能测试结果表明:单一Sr_2Ni_(0.4)Co_(1.6)O_6和薄层石墨烯的氧还原反应(ORR)最大电流密度分别为0.1830、0.1516A/cm~2 (–0.6Vvs.Hg/Hg O),氧析出反应(OER)最大电流密度分别为0.2677、0.1174 A/cm~2 (1 V vs. Hg/HgO)。当薄层石墨烯添加量占复合催化剂质量的10%时,复合催化剂的氧催化性能最佳,ORR最大电流密度为0.2901 A/cm~2(–0.6Vvs.Hg/Hg O),OER最大电流密度为0.3905 A/cm~2 (1 V vs. Hg/HgO),明显高于单一催化剂。
A double perovskite oxide Sr_2Ni_(0.4)Co_(1.6)O_6 and thin layer graphene were prepared by sol-gel method and modified Hummers reduction method, respectively. Then, graphene/Sr_2Ni_(0.4)Co_(1.6)O_6 composites were synthesized as bifunctional oxygen electrode for testing its oxygen catalytic performance. The samples were characterized by XRD, EDS, SEM and FTIR. The results indicated that Sr_2Ni_(0.4)Co_(1.6)O_6 was homogeneously dispersed on the surface of the graphene layers. Electrochemical performance tests showed that for single Sr_2Ni_(0.4)Co_(1.6)O_6 and thin layer graphene, the corresponding maximum current density of oxygen reduction reaction(ORR) was 0.1830 A/cm~2 and 0.1516 A/cm~2(–0.6 V vs. Hg/HgO), and that of oxygen evolution reaction(OER) was 0.2677 A/cm~2 and 0.1174 A/cm~2(1 V vs. Hg/HgO). When the addition amount of thin layer graphene was 10% of the mass of the composite catalyst, the composite catalyst had the best oxygen catalytic performance, the maximum current density of ORR and OER was0.2901 A/cm~2(–0.6 V vs. Hg/HgO) and 0.3905 A/cm~2(1 V vs. Hg/HgO), respectively, higher than that of the single catalyst.
引文
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