As one of the promising avenues for resource utilization of CO₂, photo-assisted Zn–CO₂ batteries can not only consume CO₂ to alleviate environmental problems, but also generate high-value chemicals and at the same time realize the generation of electrical energy. This technology can be described as “shoot two birds with one stone”. However, the round trip efficiency of Zn–CO₂ batteries has been a major obstacle for depth development. Herein, we report photo-assisted Zn–CO₂ batteries over a Cu₂O/CuCoCr-LDH (layered double hydroxide) photocathode with ultrathin p–n type heterojunction nanosheets fabricated by in situ reduction of the CuCoCr-LDH precursor which allowed the achievement of the photoelectric catalytic conversion of CO₂ to CO (maximum product yield of 1167.6 μmol g⁻¹ h⁻¹ and an outstanding selectivity of 90.14% under −1.0 V RHE). Compared with the photo-free Zn–CO₂ counterpart, the discharge voltage for the photo-assisted Zn–CO₂ battery increased to 1.22 V from 0.59 V and the round trip efficiency increased to 58.94% from 23.79%. This performance improvement can be attributed to the ultrathin p–n type heterojunction nanosheets on the photocathode for the effective separation of photogenerated electrons and holes, not only for the discharge process of CO₂ reduction, but also for the charge process of water oxidation. This work confirmed that the ultrathin p–n type heterojunction nanosheets played a significant role for photogenerated carriers in Zn–CO₂ batteries and provided a prospective and innovative approach for developing metal–CO₂ electrochemical devices.

中文翻译：

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用于光辅助水相 Zn-CO2 电池的超薄 p-n 型 Cu2O/CuCoCr 层状双氢氧化物异质结纳米片

作为CO ₂资源化利用的有前景的途径之一，光辅助Zn-CO ₂电池不仅可以消耗CO ₂来缓解环境问题，还可以产生高价值的化学品，同时实现电能的产生。 . 这项技术可谓“一石二鸟”。然而，Zn-CO ₂电池的往返效率一直是深度开发的主要障碍。在此，我们报告了在 Cu ₂ O/CuCoCr-LDH（层状双氢氧化物）光电阴极上的光辅助 Zn-CO ₂电池，该阴极具有由原位制造的超薄 p-n 型异质结纳米片。CuCoCr-LDH 前驱体的还原，从而实现了 CO ₂到 CO的光电催化转化（最大产物产率为 1167.6 μmol g ^-1 h ^-1并且在 -1.0 V RHE 下具有 90.14% 的出色选择性）。与无光Zn-CO ₂对应物相比，光辅助Zn-CO ₂电池的放电电压从0.59 V增加到1.22 V，往返效率从23.79%增加到58.94%。这种性能提升可归因于光电阴极上的超薄 p-n 型异质结纳米片有效分离光生电子和空穴，不仅适用于 CO ₂的放电过程还原，也用于水氧化的充电过程。这项工作证实了超薄 p-n 型异质结纳米片对 Zn-CO ₂电池中的光生载流子发挥了重要作用，并为开发金属-CO ₂电化学装置提供了一种前瞻性和创新的方法。