Inorganic photocatalytic materials exhibiting a highly efficient response to ultraviolet-visible light spectrum have become a subject of widespread global interest. They offer a substantial prospect for generating green energy and mitigating water pollution. Zinc oxide (ZnO), among various semiconductors, proves advantageous for water-splitting applications due to its elevated reactivity, chemical stability, and nontoxic nature. However, its efficacy as a photocatalyst is hindered by limited light absorption capacity and swift charge carrier recombination. To improve charge separation and enhance responsiveness to ultraviolet-visible light photocatalysis, the formation of a heterojunction with another suitable semiconductor is beneficial. Thus, we employed hydrothermal route for the synthesis of the samples, which is a high-pressure method. The formations of ZnO/NiO heterostructures were revealed by scanning electron microscopy, X-ray diffraction analysis, energy-dispersive X-ray spectroscopy, and Fourier transform infrared spectroscopy. The nanocomposites were discovered to have a substantially higher photocatalytic activity for the generation of H₂. The H₂ production rates show that ZnO (i.e., 168.91 molg^-1 h^-1) exhibits good H₂ production rates as compared to NiO (i.e., 135.74 molg^-1 h^-1). The best production rates were observed for ZN-30 (i.e., 247.56 molg^-1 h^-1) which is 1.46 times greater than ZnO and 1.82 times greater than NiO. This enhanced photocatalytic activity for ZN-30 is because of the good electron-hole pair separation due to the formation of depletion layer, suppression of fast charge recombination, and overcoming resistance corrosion.

中文翻译：

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具有增强光催化产氢功能的 ZnO/NiO 纳米复合材料

对紫外-可见光谱表现出高效响应的无机光催化材料已成为全球广泛关注的主题。它们为产生绿色能源和减轻水污染提供了广阔的前景。在各种半导体中，氧化锌 (ZnO) 因其较高的反应活性、化学稳定性和无毒性质而被证明在水分解应用中具有优势。然而，其作为光催化剂的功效受到有限的光吸收能力和快速载流子复合的阻碍。为了改善电荷分离并增强对紫外-可见光光催化的响应性，与另一种合适的半导体形成异质结是有益的。因此，我们采用水热路线来合成样品，这是一种高压方法。通过扫描电子显微镜、X射线衍射分析、能量色散X射线光谱和傅里叶变换红外光谱揭示了ZnO/NiO异质结构的形成。发现纳米复合材料对于产生H ₂具有显着更高的光催化活性。 H ₂生产率表明，与NiO（即，135.74  molg ^-1  h ^-1 ）相比，ZnO（即，168.91  molg ^-1  h ^-1）表现出良好的H ₂生产率。 ZN-30 的产率最高（即 247.56  molg ^-1  h ^-1），比 ZnO 高 1.46 倍，比 NiO 高 1.82 倍。 ZN-30 增强的光催化活性是由于耗尽层的形成、抑制快速电荷复合以及克服电阻腐蚀而实现的良好的电子-空穴对分离。