Fabrication of efficient photocatalysts with great visible light utilization ability, rapid carriers’ separation, and suitable redox potential is essential for improving photocatalytic CO₂ reduction. Herein, flower-like microspheres Bi₂Sn₂O₇/NiAl-layered double hydroxide (BSO/LDH) heterojunctions were prepared by hydrothermal process for CO₂ reduction. The Bi₂Sn₂O₇ nanoparticles were dispersed on NiAl-LDH nanosheets, with tight contact interface, which facilitated charges transfer and exposing more catalytic active sites. Results of photochemical deposition of metal/metal oxide demonstrated that interfacial charges transfer of the BSO/LDH followed Z-scheme mechanism, endowing more desired redox potential and more efficient carriers separation. The 30%-BSO/LDH showed the highest CO and CH₄ yields of 37.91 and 1.18 μmol g⁻¹ h⁻¹ under visible light irradiation, 3.4 and 2.0 times higher than those from the NiAl-LDH, respectively. The main intermediates during CO₂ reduction were carboxylate (COOH*) and aldehyde group (CHO*), and CO₂ reduction pathways and mechanism were proposed accordingly. This study provided referential strategy for designing efficient heterojunction photocatalysts for CO₂ conversion.

制备具有良好的可见光利用能力、快速的载流子分离和合适的氧化还原电位的高效光催化剂对于改善光催化CO ₂还原至关重要。在此，通过水热法制备了花状微球Bi ₂ Sn ₂ O ₇ /NiAl层状双氢氧化物（BSO/LDH）异质结，用于CO ₂还原。Bi ₂ Sn ₂ O ₇纳米粒子分散在NiAl-LDH纳米片上，具有紧密的接触界面，有利于电荷转移并暴露更多的催化活性位点。金属/金属氧化物的光化学沉积结果表明，BSO/LDH的界面电荷转移遵循Z-方案机制，赋予了更理想的氧化还原电位和更有效的载流子分离。在可见光照射下， 30%-BSO/LDH 的 CO 和 CH ₄产率最高，分别为 37.91 和 1.18 μmol g ^-1  h ^-1，分别是 NiAl-LDH 的 3.4 倍和 2.0 倍。_{CO 2}还原过程中的主要中间体是羧酸盐（COOH*）和醛基（CHO*），以及CO ₂相应地提出了减排途径和机制。该研究为设计用于CO ₂转化的高效异质结光催化剂提供了参考策略。