Abstract A simple aqueous solution process was used for the synthesis of Cu-loaded ZnO nanorod structures in which highly crystalline and hexagonal wurtzite ZnO, cubic CuO and Cu2O phases coexist. Absorption/emission characteristics identify band gap narrowing, which facilitates visible light absorption, as a consequence of hybridization of O 2p bands with Cu 3 d bands of the ZnO-CuxO heterostructure system. With use of the specific band energy position of the individual components (i.e., ZnO, Cu2O, and CuO), photogenerated electrons and holes could be made to migrate separately and thereby the carrier recombination could be delayed, making them amply available for photocatalytic reactions. The available electrons plausibly produce superoxide radical anion (O2·−), while holes generate hydroxyl radicals (·OH), which are reactive agents for dye degradation. Furthermore, the formation of a depletion region via Cu-induced charge separation within the ZnO-CuxO heterostructure and thermal-energy-mediated abstraction of the electric field barriers and subsequent migration of the positively charged defects from the subsurface region toward the interface lead to efficient photocatalytic performance.

中文翻译：

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用于高效染料降解的 ZnO-Cu O 异质结构光催化剂

摘要 采用一种简单的水溶液工艺合成了高度结晶的六方纤锌矿ZnO、立方CuO和Cu2O相共存的Cu负载ZnO纳米棒结构。由于 O 2p 带与 ZnO-CuxO 异质结构系统的 Cu 3 d 带杂交，吸收/发射特性确定带隙变窄，这有利于可见光吸收。利用各个组分（即 ZnO、Cu2O 和 CuO）的特定带能位置，可以使光生电子和空穴分别迁移，从而延迟载流子复合，使其可充分用于光催化反应。可用电子可能产生超氧自由基阴离子（O2·−），而空穴产生羟基自由基（·OH），它们是染料降解的活性剂。此外，通过在 ZnO-CuxO 异质结构内通过 Cu 诱导的电荷分离和热能介导的电场势垒提取以及随后带正电的缺陷从表面下区域向界面迁移，形成耗尽区导致高效光催化性能。