Visible light-driven photocatalytic reduction of CO 2 into value-added chemical fuel is considered as an up-and-coming pathway for CO 2 conversion utilizing green solar energy. Herein, we report heterostructures of NH 2 -MIL-101(Fe)/g-C 3 N 4 (g-C 3 N 4 = polymeric graphite-like carbon nitride) as prominent photocatalysts for the reduction of CO 2 via a solvent-free reaction. Among these heterogeneous photocatalysts, NH 2 -MIL-101(Fe)/g-C 3 N 4 -30 wt % referred to as MCN-3 shows superior catalytic activity for photocatalytic reduction of CO 2 to CO with a CO yield of 132.8 μmol g −1 , which is more than 3.6 times higher than that for pristine NH 2 -MIL-101(Fe) and 6.9 times higher than that for sole g-C 3 N 4 . In virtue of the elaborate designed photocatalysts and the gas−solid interfacial route, the heterostructure of NH 2 -MIL-101(Fe)/g-C 3 N 4 with efficient interfacial electron transfer between NH 2 -MIL-101(Fe) and g-C 3 N 4 results in the boosted photocatalytic reduction of CO 2 upon visible light irradiation.

The amino group of UiO-66-NH2 was demonstrated to play an important role in selective fluorescence turn-on sensing of lysine and arginine.

Photocatalytic reduction of CO 2 has drawn much attention as a promising way that can effectively alleviate the issue of global warming and energy crisis. In this work, we fabricated a series of CdS/NH 2 -UiO-66 composites with varied CdS amounts and tested their capacity for photocatalytic reduction of CO 2 . The reactions were performed in a solvent-free system and displayed excellent selectivity for CO production without liquid phase products. When the content of CdS in the composite is up to 40 %, the hybrid catalyst produces 105.41 μmol/g within 6 h, exhibiting remarkable photocatalytic performance, which is much higher than that catalyzed by mechanically mixed CdS and NH 2 -UiO-66. The brilliant catalytic performance of the composite catalyst is attributed to the formation of heterostructure between the well-dispersed CdS and NH 2 -UiO-66, which promotes the enhancement of electron transfer during photocatalysis. Figure 7. Proposed mechanism of photocatalytic reduction of CO 2 by the CdS/NH 2 -UiO-66 composite photocatalyst under visible light irradiation.