The doping of transition metal into MgAl layered double hydroxide to create surface defects has been considered as an effective strategy to tailor band gap and promote electron transfer in CO₂ photoreduction. Nevertheless, the report about comprehensive effect of doped elements in the whole reaction process, especially in CO₂ surface reduction, is still lacking. Herein, the detailed mechanism of doped elements for activity improvement in light absorption, charge transport and surface reaction was revealed by the experiment and DFT calculation. The optimal doped element was screened from 5 kinds of metal elements (Co, Ni, Cu, Fe, and Cr) by the photocatalytic test with TEOA and [Ru(bpy)₃]Cl₂ as sacrificial agent and photosensitizer. Cr doped LDH was the optimal choice with the highest TOF value for CO production and the CO evolution rate of 3.91 μmol•g⁻¹•h⁻¹. The doping of Cr could reduce the band gap, introduce the intermediate band, generate more surface defects and obtain the lower energy of CO release, which accounted for the high activity comprehensively.

将过渡金属掺杂到 MgAl 层状双氢氧化物中以产生表面缺陷已被认为是调整带隙和促进 CO ₂光还原中电子转移的有效策略。尽管如此，关于掺杂元素在整个反应过程中，特别是在CO ₂表面还原中的综合作用的报道仍然缺乏。在此，通过实验和 DFT 计算揭示了掺杂元素提高光吸收、电荷传输和表面反应活性的详细机制。_{通过TEOA和[Ru(bpy) 3} ]Cl ₂的光催化试验从5种金属元素(Co、Ni、Cu、Fe和Cr)中筛选出最佳掺杂元素作为牺牲剂和光敏剂。Cr掺杂的LDH是CO产生的TOF值最高的最佳选择，CO的释放速率为3.91 μmol•g ^-1 •h ^-1。Cr的掺杂可以减小带隙，引入中间带，产生更多的表面缺陷，获得较低的CO释放能量，综合考虑了较高的活性。