Heterostructures have delivered phenomenal photoelectrochemical performance owing to their excellent physicochemical properties. We report on the utilization of controlled Au@ZnO nano-heteroarchitectures for efficient water splitting. The ZnO nanowires of an average length and a diameter of ∼5–6 μm and 120 nm, respectively, synthesized by the hydrothermal method were subjected to the controlled decoration of Au nanoparticles of diameter ∼20 nm. The cubic crystalline Au nanoparticles were decorated on the hexagonal wurtzite ZnO nanowires under a controlled reaction time. A 12 h reaction time has resulted in the uniform decoration of Au nanoparticles along the surface of ZnO nanowires, and a further increase in the reaction time ensured their agglomeration in the array of ZnO nanowires. XPS analysis revealed the existence of pure metallic Au on ZnO nanowires without altering the stoichiometry. The Au@ZnO nano-heteroarchitecture with a 12 h reaction time delivered a maximum photocurrent density of 1.04 A cm⁻², which is a 52-fold increase than that of pristine ZnO nanowires. The ABPE value is 0.59%, which is approximately five-fold higher than that of the pristine ZnO nanowires. This reveals that the controlled decoration of Au nanoparticles along the surface of ZnO nanowires has altered the Fermi energy position significantly and facilitated the injection of hot electrons from the SP state into the conduction band of ZnO, effectively.

中文翻译：

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金负载量对增强Au @ ZnO纳米异质结构光电化学活性的影响

异质结构由于其出色的物理化学特性而具有惊人的光电化学性能。我们报告了受控的Au @ ZnO纳米异质结构用于有效的水分解的利用。通过水热法合成的平均长度分别为5-6μm的ZnO纳米线和120nm的直径的纳米线受到直径20nm的金纳米粒子的可控装饰。在控制的反应时间下在立方纤锌矿型ZnO纳米线上装饰了立方晶金Au纳米颗粒。12 h的反应时间导致Au纳米颗粒沿着ZnO纳米线的表面均匀装饰，并且反应时间的进一步增加确保了它们在ZnO纳米线阵列中的团聚。XPS分析表明，在不改变化学计量的情况下，ZnO纳米线上存在纯金属金。反应时间为12 h的Au @ ZnO纳米异质结构的最大光电流密度为1.04 A cm^-2，是原始ZnO纳米线的52倍。ABPE值为0.59％，约为原始ZnO纳米线的五倍。这表明，沿着ZnO纳米线表面的Au纳米粒子的受控装饰显着改变了费米能级，并有效地促进了热电子从SP态注入到ZnO导带中。