The photocatalytic nonoxidative coupling of methane (NOCM) represents an appealing approach for addressing global warming and producing sustainable chemical commodities. However, the effectiveness of this process is hindered by the challenge of adsorbing and activating methane due to its high inertness. In this study, we synthesized Au/ZnO nanocomposites featuring different exposed facets of Au as co-catalysts and investigated their influence on the photocatalytic activity of NOCM. Our results indicate that Au octahedra with exposed (111) facets achieved the highest ethane yield of 21.0 μmol cm⁻² h⁻¹ under ambient temperature and pressure conditions, exceeding the yields of Au cubes with exposed (100) facets and Au rhombic dodecahedra with exposed (110) facets by 2.3 and 3.0 times, respectively. Through experimental and theoretical analyses, we found that the facet of Au co-catalysts had a negligible effect on the separation efficiency of photoinduced carriers and the activation ability of methane. However, the Au(111) facets exhibited the strongest adsorption capacity of methane compared to Au(100) and Au(110) facets, which was related to the greater electron richness of Au(111) facets, leading to stronger interaction with methane and enhanced photocatalytic performance. This study highlights the importance of facet engineering of co-catalysts to enhance the photocatalytic performance in methane conversion.

中文翻译：

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了解甲烷光催化非氧化偶联中的金面效应

甲烷光催化非氧化偶联（NOCM）代表了解决全球变暖和生产可持续化学商品的一种有吸引力的方法。然而，由于甲烷的高惰性，吸附和活化甲烷的挑战阻碍了该过程的有效性。在这项研究中，我们合成了具有不同暴露面的Au作为助催化剂的Au/ZnO纳米复合材料，并研究了它们对NOCM光催化活性的影响。我们的结果表明，在环境温度和压力条件下，具有暴露（111）面的Au八面体实现了最高的乙烷产率21.0 μmol cm ^-2 h ^-1，超过了具有暴露（100）面的Au立方体和具有暴露的Au菱形十二面体的产率。暴露的 (110) 面分别为 2.3 和 3.0 倍。通过实验和理论分析，我们发现Au助催化剂的面对光生载流子的分离效率和甲烷的活化能力的影响可以忽略不计。然而，与Au(100)和Au(110)晶面相比，Au(111)晶面对甲烷的吸附能力最强，这与Au(111)晶面的电子丰富度较高有关，导致与甲烷和甲烷的相互作用更强。增强光催化性能。这项研究强调了助催化剂的面工程对于增强甲烷转化中的光催化性能的重要性。