Induce (101) plane exposure boosting photocatalytic CO2 reduction in aerobic environment for NH2-MIL-125

NH 2 -MIL-125 with abundant porosity and specific interactions with CO 2 molecules, has been demonstrate great potential in the field of photocatalytic CO 2 reduction. However, conventional NH 2 -MIL-125 and their composites much lower CO 2 photoreduction efficiency in aerobic environments because of the O 2 competition. To circumvent the issue, this study modifies NH 2 -MIL-125 through crystal facet engineering to enhance its selective CO 2 adsorption and photocatalytic efficiency in the environment of impurity CO 2 . The results indicate that NH 2 -MIL-125 featuring (101) crystal planes can sustain elevated catalytic activity in low-concentration CO 2 environments. In a pure CO 2 atmosphere, NM-5 achieves a CO production rate of 159.66 μmol·g −1 after 4 h, 1.85 times greater than the unmodified NH 2 -MIL-125. Under conditions simulating flue gas (5 % CO 2 ) and ultra-low CO 2 concentrations (0.15 % CO 2 ), NM-5 maintains CO production rates of 3.18 μmol·g −1 and 0.95 μmol·g −1 , respectively, representing 1.63 and 1.73 times the production rates of NM. Furthermore, theoretical calculations indicate that CO 2 exhibits a higher adsorption energy (−1.34 eV) compared to N 2 and O 2 (−0.67 eV and −0.15 eV) on the (101) crystal plane, which reveals the preferential adsorption of CO 2 on the (101) crystal planes. This study involves a novel strategy for optimizing MOFs crystal planes and provides significant insights into achieving efficient photocatalytic CO 2 reduction under aerobic conditions.