Abstract Hematite α-Fe2O3 nanoparticle synthesis via a facile and eco-friendly hydrothermal method has been hybridized by different loading of graphene obtained by the pyrolysis of biopolymers (alginate, chitosan and carrageenan). The resulting α-Fe2O3-Gr catalyst shows a high catalytic activity of ~98% toward RhB degradation under visible light irradiation. The existence of N and S heteroatoms on the surface of the graphene affects the size of nanoparticles and the specific surface area in the α-Fe2O3-Gr, with a negative effect on catalytic performance. Electron Spin Resonance (ESR) studies showed that the hydroxyl radical OH was the main reactive species responsible for the degradation of RhB. The reusability of α-Fe2O3-Gr was studied and the catalyst kept good stability and high activity over four cycles with no change in the morphology of the catalysts. Interestingly, incorporation of graphene into hematite nanoparticles resulted in superior photocatalytic activity compared to α-Fe2O3 loaded on carbon nanotubes, active carbons and biochar.

中文翻译：

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新型α-Fe2O3/石墨烯在可见光增强光催化降解RhB中的合成及应用

摘要 通过生物聚合物（藻酸盐、壳聚糖和角叉菜胶）热解获得的石墨烯的不同负载量，通过一种简便且环保的水热法合成赤铁矿 α-Fe2O3 纳米颗粒。所得的 α-Fe2O3-Gr 催化剂在可见光照射下对 RhB 降解显示出约 98% 的高催化活性。石墨烯表面存在 N 和 S 杂原子会影响纳米粒子的尺寸和 α-Fe2O3-Gr 中的比表面积，对催化性能产生负面影响。电子自旋共振 (ESR) 研究表明，羟基自由基 OH 是导致 RhB 降解的主要反应物质。研究了 α-Fe2O3-Gr 的可重复使用性，催化剂在 4 个循环后保持良好的稳定性和高活性，催化剂的形貌没有变化。有趣的是，与负载在碳纳米管、活性炭和生物炭上的 α-Fe2O3 相比，将石墨烯掺入赤铁矿纳米颗粒导致了优异的光催化活性。