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

NH2-MIL-125 with abundant porosity and specific interactions with CO2 molecules, has been demonstrate great potential in the field of photocatalytic CO2 reduction. However, conventional NH2-MIL-125 and their composites much lower CO2 photoreduction efficiency in aerobic environments because of the O2 competition. To circumvent the issue, this study modifies NH2-MIL-125 through crystal facet engineering to enhance its selective CO2 adsorption and photocatalytic efficiency in the environment of impurity CO2. The results indicate that NH2- MIL-125 featuring (101) crystal planes can sustain elevated catalytic activity in low-concentration CO2 environments. In a pure CO2 atmosphere, NM-5 achieves a CO production rate of 159.66 mu mol center dot g-1 after 4 h, 1.85 times greater than the unmodified NH2-MIL-125. Under conditions simulating flue gas (5 % CO2) and ultra-low CO2 concentrations (0.15 % CO2), NM-5 maintains CO production rates of 3.18 mu mol center dot g-1 and 0.95 mu mol center dot g-1, respectively, representing 1.63 and 1.73 times the production rates of NM. Furthermore, theoretical calculations indicate that CO2 exhibits a higher adsorption energy (-1.34 eV) compared to N2 and O2 (-0.67 eV and-0.15 eV) on the (101) crystal plane, which reveals the preferential adsorption of CO2 on the (101) crystal planes. This study involves a novel strategy for optimizing MOFs crystal planes and provides significant insights into achieving efficient photocatalytic CO2 reduction under aerobic conditions.