Abstract Highly efficient ternary heterojunction of CuO/α-Fe2O3/γ-Al2O3 was effectively fabricated by a facile and cost effective chemical route. The structural, chemical composition, morphology, optical and photocatalytic properties of as-prepared CuO/α-Fe2O3/γ-Al2O3 photo catalyst were compared to pristine and binary samples by various characterization. Existence of all the dominant peaks of CuO, α-Fe2O3 and γ-Al2O3 are noticeable in XRD spectrum of CuO/α-Fe2O3/γ-Al2O3 ternary photo catalyst which confirms the successful formation of the photocatalyst. SEM and HRTEM results revealed the spherical shape CuO nanoparticles with distorted α-Fe2O3 agglomerated plates which led to complete diffusion with γ-Al2O3. The band gap of ternary nanocomposite was found to be 1.9 eV elucidated by UV-DRS. Brunauer-Emmett-Teller (BET) analysis shown that due to the unique ternary nanocomposite structure and synergistic effect among various components, as-fabricated ternary CuO/α-Fe2O3/γ-Al2O3 nanocomposite exhibited the porous structure with large surface area and small pore volume as compared to pristine γ-Al2O3. The photocatalytic activity was examined by monitoring the deterioration of methyl orange under simulated solar light irradiation. CuO/α-Fe2O3/γ-Al2O3 exhibited superior photocatalytic efficacy as compared to CuO/γ-Al2O3 and α-Fe2O3/γ-Al2O3 binary and pure oxides of γ-Al2O3, CuO and α-Fe2O3. The marvelous photocatalytic activity of CuO/α-Fe2O3/γ-Al2O3 ternary nanocomposite samples can be ascribed to their close contact, strong interfacial hybridization and proficient charge transfer capacity. The electrochemical studies such as linear sweep voltammetry (LSV) and cyclic voltammetry (CV) were carried out to explore the charge transfer behavior and to support the high photo activity of ternary nanocomposite CuO/α-Fe2O3/γ-Al2O3. LSV measurements manifested that CuO/α-Fe2O3/γ-Al2O3 exhibited 4.3 folds higher current density than bare γ-Al2O3 which confirmed the faster electron transfer from CuO to γ-Al2O3 via mediated α-Fe2O3 through the interfacial potential gradient in conduction band. Cyclic voltammetry (CV) results shown that pair of anodic and cathodic peaks in CuO/α-Fe2O3/γ-Al2O3 which affirm the efficient increase in photo-induced e-/h+ separation and suppress recombination rate of electron-hole pair. This work demonstrated that CuO/α-Fe2O3/γ-Al2O3 ternary nanocomposite found to be a promising candidate as an efficient adsorbent for organic dye removal from waste water.

中文翻译：

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三元CuO/α-Fe2O3/γ-Al2O3纳米复合材料中的级联电子转移作为一种有效的可见光催化剂

摘要 通过简便且经济高效的化学途径制备了高效的 CuO/α-Fe2O3/γ-Al2O3 三元异质结。通过各种表征将所制备的 CuO/α-Fe2O3/γ-Al2O3 光催化剂的结构、化学成分、形貌、光学和光催化性能与原始和二元样品进行了比较。在 CuO/α-Fe2O3/γ-Al2O3 三元光催化剂的 XRD 谱中，CuO、α-Fe2O3 和 γ-Al2O3 的所有主峰都存在，这证实了光催化剂的成功形成。SEM 和 HRTEM 结果显示球形 CuO 纳米颗粒具有扭曲的 α-Fe2O3 团聚板，导致与 γ-Al2O3 完全扩散。UV-DRS 表明三元纳米复合材料的带隙为 1.9 eV。Brunauer-Emmett-Teller (BET) 分析表明，由于独特的三元纳米复合结构和各组分之间的协同作用，制备的三元 CuO/α-Fe2O3/γ-Al2O3 纳米复合材料具有大比表面积和小孔的多孔结构。体积与原始 γ-Al2O3 相比。通过在模拟太阳光照射下监测甲基橙的劣化来检查光催化活性。与 CuO/γ-Al2O3 和 α-Fe2O3/γ-Al2O3 二元和 γ-Al2O3、CuO 和 α-Fe2O3 的纯氧化物相比，CuO/α-Fe2O3/γ-Al2O3 表现出优异的光催化功效。CuO/α-Fe2O3/γ-Al2O3 三元纳米复合样品的奇妙光催化活性可归因于它们的紧密接触、强界面杂化和良好的电荷转移能力。进行了线性扫描伏安法 (LSV) 和循环伏安法 (CV) 等电化学研究，以探索电荷转移行为并支持三元纳米复合材料 CuO/α-Fe2O3/γ-Al2O3 的高光活性。LSV 测量表明，CuO/α-Fe2O3/γ-Al2O3 显示出比裸 γ-Al2O3 高 4.3 倍的电流密度，这证实了通过介导的 α-Fe2O3 通过导带中的界面电位梯度，从 CuO 到 γ-Al2O3 的电子转移速度更快。循环伏安法 (CV) 结果表明，CuO/α-Fe2O3/γ-Al2O3 中的一对阳极和阴极峰证实了光致 e-/h+ 分离的有效增加并抑制了电子 - 空穴对的复合率。