Photocatalytic reduction of CO₂ into solar fuels is regarded as one of the most promising approaches to address the issues of global warming and the energy crisis. The promotion of spatial charge separation and transfer through crystal facet engineering could be conducive to improved photocatalytic activity. In this study, one-dimensional (1D) WO₃ nanowires with a {110} dominant facet (WO₃-110) and two-dimensional (2D) WO₃ nanosheets with a {001} dominant facet (WO₃-001) coupled with CuO nanoparticles are fabricated by a facile method and used for CO₂ photoreduction. Its composition and structural characterizations suggest that the WO₃–CuO hybrid features good contact between the WO₃ and CuO nanostructures. Under light irradiation, the WO₃ and WO₃–CuO nanostructures are able to photoreduce CO₂ into CH₄. Notably, the prepared WO₃–CuO nanohybrids with different exposed facets show improved CO₂ reduction capability compared to pure WO₃ and CuO. The heterojunction interface between the WO₃ photocatalyst and the CuO cocatalyst through p–n contact can facilitate electron–hole pair separation and accordingly results in enhanced photocatalytic performance. With the assistance of the CuO cocatalyst, the {110} facet WO₃–CuO hybrid displays superior photoreduction capability compared to the {001} facet WO₃–CuO, which is attributed to the difference in the crystal facets in the heterostructure. The {110} facet WO₃ nanowires have a more negative conduction band edge, contributing to the higher reduction capacity of this sample. On the other hand, it is shown that faster charge carrier transfer efficiency would enable more photoinduced electrons to participate in CO₂ photoreduction, especially with the involvement of the nanoparticulate CuO cocatalyst. This work provides guidance for designing a hetero-photocatalyst–cocatalyst system through crystal facet engineering.

中文翻译：

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一维/ 2维WO3纳米结构与纳米颗粒CuO助催化剂的结合，可增强太阳能驱动的CO2光还原：晶面的影响

将CO ₂光催化还原为太阳能燃料被认为是解决全球变暖和能源危机问题的最有前途的方法之一。通过晶体刻面工程促进空间电荷的分离和转移可能有助于改善光催化活性。在这项研究中，具有{110}主刻面（WO ₃ -110）的一维（1D）WO ₃纳米线和具有{001}主刻面（WO ₃ -001）的二维（2D）WO ₃纳米片用方便的方法制备CuO纳米颗粒并用于CO _2光还原。其组成和结构特征表明WO ₃–CuO杂化物具有WO ₃和CuO纳米结构之间的良好接触。在光照射下，WO ₃和WO ₃ -CuO纳米结构能够将CO _2光还原为CH ₄。值得注意的是，与纯WO ₃和CuO相比，制备的具有不同暴露面的WO ₃ -CuO纳米杂化物显示出更高的CO ₂还原能力。通过p–n接触，WO ₃光催化剂和CuO助催化剂之间的异质结界面可以促进电子-空穴对的分离，从而提高光催化性能。在CuO助催化剂的协助下，{110}面WO ₃与{001}晶面WO ₃ -CuO相比，–CuO杂化物显示出优异的光还原能力，这归因于异质结构中晶面的差异。{110}刻面WO ₃纳米线的负导带边缘更大，从而有助于该样品的更高还原能力。另一方面，表明更快的电荷载流子转移效率将使得更多的光诱导电子能够参与CO _2的光还原，特别是在纳米颗粒CuO助催化剂的参与下。这项工作为通过晶面工程设计杂化光催化剂-助催化剂系统提供了指导。