出 处:《Chinese Journal of Catalysis》2025年第3期333-340,共8页催化学报(英文)
基 金:江西省自然科学基金(20224BAB203018,20224ACB213010,20232BAB213050,20232ACB203022);江西省“双千计划”(jxsq2023102143,jxsq2023102142,jxsq2023201086,jxsq2023102141,jxsq2019102053);国家自然科学基金(22462010,22366018,5236005);清江优秀青年人才计划,JXUST(JXUSTQJBJ2020005).
摘 要:The rapid recombination of photogenerated carriers poses a significant limitation on the use of CdS quantum dots(QDs)in photocatalysis.Herein,the construction of a novel S-scheme heterojunction between cubic-phase CdS QDs and hollow nanotube In_(2)O_(3)is successfully achieved using an electrostatic self-assembly method.Under visible light irradiation,all CdS-In_(2)O_(3)composites exhibit higher hydrogen evolution efficiency compared to pure CdS QDs.Notably,the photocatalytic H_(2)evolution rate of the optimal CdS-7%In_(2)O_(3)composite is determined to be 2258.59μmol g^(−1)h^(−1),approximately 12.3 times higher than that of pure CdS.The cyclic test indicates that the CdS-In_(2)O_(3)composite maintains considerable activity even after 5 cycles,indicating its excellent stability.In situ X-ray photoelectron spectroscopy and density functional theory calculations confirm that carrier migration in CdS-In_(2)O_(3)composites adheres to a typical S-scheme heterojunction mechanism.Additionally,a series of characterizations demonstrate that the formation of S-scheme heterojunctions between In_(2)O_(3)and CdS inhibits charge recombination and accelerates the separation and migration of photogenerated carriers in the CdS QDs,thus achieving enhanced photocatalytic performance.This work elucidates the pivotal role of S-scheme heterojunctions in photocatalytic H_(2)production and offers novel insights into the construction of effective composite photocatalysts.CdS由于具有合适的带隙和易于调节的表面结构,被广泛应用于光催化制氢领域.CdS具有比H_(2)/H_(2)O电位更负的导带(CB),有利于H_(2)的析出.此外,CdS量子点(QDs)的量子尺寸效应有助于提高光催化性能,带隙的可调性使它们能够吸收更宽范.围的可见光.然而,CdS表现出严重的光生载流子复合现象,并且易发生空穴氧化光腐蚀,这极大地限制了其在光催化领域的应用.为了解决这些问题,已经提出了许多有效的策略,包括形貌调控、元素掺杂和异质结构建.在这些策略中,用另一种合适的半导体构建S型异质结是一种很有前途的方法.S型异质结的构建使氧化和还原反应能够在不同的位置发生,从而促进光生电荷的空间分离.因此,合理构建S型异质结构是提高CdS光催化活性的可行途径.本文通过静电自组装法成功地构建了CdS QDs和In_(2)O_(3)空心纳米管之间的S型异质结,并探究了其在光催化产氢中的应用.在该体系中,独特的空心纳米管结构赋予了复合光催化剂更大的比表面积和丰富的H_(2)析出位点,而S型异质结的形成有效地促进了CdS-In_(2)O_(3)复合材料内光生载流子的分离和转移.Zeta电位测试结果表明,CdS QDs带负电,而3-氨丙基三乙氧基硅烷修饰的In_(2)O_(3)带正电,这为CdS-In_(2)O_(3)复合材料的静电自组装提供依据.此外,通过紫外-可见漫反射光谱、Tauc曲线和莫特-肖特基图谱等研究了CdS和In_(2)O_(3)的能级结构,发现两种材料的能级位置交错排列,有利于形成S型异质结.通过原位光照X射线光电子能谱(XPS)和密度泛函理论计算研究了载流子的转移机制,验证了CdS-In_(2)O_(3)复合材料的S型异质结机制.功函数计算结果表明,In_(2)O_(3)具有比CdS更高的费米能级(E_f),有利于电子从In_(2)O_(3)转移到Cd,这与原位XPS分析结果一致.因此,与纯CdS相比,CdS-In_(2)O_(3)复合材料的光催化产氢性能显著提升.值得注意的是,
关 键 词:CdS IN2O3 Quantum dot Photocatalytic H_(2)evolution S-scheme heterojunction
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