Phase-enabled metal-organic framework homojunction for highly selective CO2 photoreduction

Abstract

Conversion of clean solar energy to chemical fuels is one of the promising and up-and-coming applications of metal–organic frameworks. However, fast recombination of photogenerated charge carriers in these frameworks remains the most significant limitation for their photocatalytic application. Although the construction of homojunctions is a promising solution, it remains very challenging to synthesize them. Herein, we report a well-defined hierarchical homojunction based on metal–organic frameworks via a facile one-pot synthesis route directed by hollow transition metal nanoparticles. The homojunction is enabled by two concentric stacked nanoplates with slightly different crystal phases. The enhanced charge separation in the homojunction was visualized by in-situ surface photovoltage microscopy. Moreover, the as-prepared nanostacks displayed a visible-light-driven carbon dioxide reduction with very high carbon monooxide selectivity, and excellent stability. Our work provides a powerful platform to synthesize capable metal–organic framework complexes and sheds light on the hierarchical structure-function relationships of metal–organic frameworks.

2D/2D Heterostructure of Metal-Free Ultrathin Graphdiyne/Carbon Nitride Nanosheets for Enhanced Photocatalytic Reduction of Carbon Dioxide with Water

“…It is well-known that photocatalytic CO 2 reduction largely depends on the adsorption and desorption properties of intermediates and products. According to the DFT calculation results (Figure b), the path with the *COOH and *CO intermediates presented a lower energy barrier for GD/CN than for CN, indicating that CO 2 reduction was prone to occur on GD/CN …”

“…The peaks at 1340 and 1540 cm –1 can be attributed to the bidentate bicarbonate (b-CO 3 2– ) species, and the peaks at 1396 and 1650 cm –1 can be assigned to monodentate bicarbonate (m-CO 3 2– ) species . The characteristic peaks of HCO 3 – appeared at 1438 and 1691 cm –1 . The strong adsorption of CO 2 by GD/CN facilitated photoconversion.…”

“…27 The characteristic peaks of HCO 3 − appeared at 1438 and 1691 cm −1 . 41 The strong adsorption of CO 2 by GD/CN facilitated photoconversion.…”

“…According to the DFT calculation results (Figure 8b), the path with the *COOH and *CO intermediates presented a lower energy barrier for GD/CN than for CN, indicating that CO 2 reduction was prone to occur on GD/CN. 41…”

Nanostructure@metal-organic frameworks (MOFs) for catalytic carbon dioxide (CO2) conversion in photocatalysis, electrocatalysis, and thermal catalysis

“…Encapsulating of POMs into sulfonic acid functionalized MIL-101-Cr is also reported to promote CO 2 photoreduction activity [77]. Ti-substituted POMs in POMs@HKUST-1 was verified a role of proton and electron reservoir for the activity promotion in photocatalytic CO 2 to CO [78].…”