Regulating divalent metal species in aluminum-based layered double hydroxides to selectively promote photocatalytic CO production from CO2

作者：Zhao, Jie^*; Lu, Yun; Wu, Debin; Qin, Yuancheng; Xie, Yu^*; Guo, Yue; Raza, Waseem; Luo, Geng; Mushtaq, Muhammad Asim; Wu, Yangfei; Mu, Xiaowan; Ling, Yun; Ilyas, Tayiba; Ul Hassan, Qadeer; Gao, Chenmei

来源：SEPARATION AND PURIFICATION TECHNOLOGY, 2023, 305: 122508.

DOI：10.1016/j.seppur.2022.122508

• Photocatalysis
• CO2 reduction
• Layered double hydroxides
• Selectivity
• Ions doping

Photocatalysis is a potential technology to reduce CO2 greenhouse gases. Layered double hydroxides (LDHs) are promising photocatalysts due to good catalytic activity, low synthesis cost, and large-scale preparation. However, their CO selectivity in photocatalytic CO2 reduction is still unsatisfactory. Herein, we have systematically studied the effects of different divalent metal species (e.g., Mg2+, Ni2+, and Zn2+) on the CO selectivity in aluminum-based LDHs. The results indicate that ZnAl-LDH can negatively shift the conduction band to obtain a large driving power for CO2 reduction to CO, which much improves the CO selectivity. In addition, the ZnAl-LDH also reduces the charge transfer resistance leading to a higher photo-generated current density, thus achieving a high CO2 reduction performance. Specifically, ZnAl-LDH presents a better CO selectivity of 72.8 % and a higher CO yield of 1.58 mu mol.g(-1).h(-1), than MgAl-LDH (66.2%, 0.96 mu mol.g(-1).h(-1)) and NiAl-LDH (59.8%, 1.01 mu mol.g(-1).h(-1)). This study provides a feasible strategy to improve the selectivity of CO photocatalytic reduction of CO2 by regulating divalent metal species in aluminum-based layered double hydroxides.

• 单位
  南昌航空大学; 南京大学; y