Photocatalytic reduction of CO₂ into value-added products is a promising strategy for mitigating environmental and energy problems simultaneously. Herein, we developed Au sheets with subtle grain boundaries on ultrathin Ni(OH)₂ nanosheets as efficient photocatalysts for CO₂ reduction. According to mechanistic studies, grain boundaries on the Au sheets served as electron trapping sites which enabled the optimization of electron-hole separation. Moreover, grain boundaries perturbed electron distribution, which assisted in stabilizing CO₂^δ− and HCOO* intermediates. As a result, the unique hybrid structure achieved a high rate of 75.2 µmol g⁻¹ h⁻¹ for CO₂ photoreduction. This work demonstrates the importance of defect engineering in designing active photocatalysts and also provides insight into development of related photo-energy conversion schemes.

光催化将CO ₂还原为增值产品是一种同时缓解环境和能源问题的有前途的策略。在本文中，我们开发了在超薄Ni（OH）₂纳米片上具有微妙晶界的Au片作为有效的CO ₂还原光催化剂。根据机理研究，金片上的晶界用作电子俘获位点，从而使电子-空穴分离最优化。此外，晶界扰动的电子分布，这在稳定CO辅助₂ ^{δ -}和HCOO *中间体。结果，独特的混合结构获得了很高的CO转化率，为75.2 µmol g ^-1 h ^-1_2光还原。这项工作证明了缺陷工程学在设计活性光催化剂方面的重要性，并为开发相关的光能转化方案提供了见识。