Facile electron delivery from graphene template to ultrathin metal-organic layers for boosting CO2 photoreduction

Jia-Wei Wang,Li-Zhen Qiao,Zhi-Ming Zhang,Hai-Hua Huang,Meng Liu,Zhen-Hui Kang,Tong-Bu Lu,Yi Li,Shuang Yao,Hao-Dong Nie

doi:10.1038/s41467-021-21084-9

Abstract

Metal-organic layers with ordered structure and molecular tunability are of great potential as heterogeneous catalysts due to their readily accessible active sites. Herein, we demonstrate a facile template strategy to prepare metal-organic layers with a uniform thickness of three metal coordination layers (ca. 1.5 nm) with graphene oxide as both template and electron mediator. The resulting hybrid catalyst exhibits an excellent performance for CO2 photoreduction with a total CO yield of 3133 mmol g–1MOL (CO selectivity of 95%), ca. 34 times higher than that of bulky Co-based metal-organic framework. Systematic studies reveal that well-exposed active sites in metal-organic layers, and facile electron transfer between heterogeneous and homogeneous components mediated by graphene oxide, greatly contribute to its high activity. This work highlights a facile way for constructing ultrathin metal-organic layers and demonstrates charge transfer pathway between conductive template and catalyst for boosting photocatalysis.

Highlights

Nanosizing metal-organic frameworks (MOFs) into ultrathin metal-organic layers (MOLs) can efficiently accelerate mass transport/electron transfer and create abundant readily accessible active sites to ensure high activity in various catalytic reactions[19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34]
Single-crystal X-ray diffraction analyses reveal that Co-MOF crystallizes in a monoclinic crystal system with a space group of C2/c (Supplementary Table 1)
Isotope labeling experiment with 13CO2 shows that 13CO is the main product in this photocatalytic system (Fig. 3c), manifesting that the CO product really derives from CO2 rather than the decomposition of TEOA, RuPS, graphene oxide (GO), or Co-MOLs. All these results demonstrate the excellent stability of Co-MOL@GO in the photocatalytic CO2-to-CO conversion

Summary

Introduction

Nanosizing MOFs into ultrathin metal-organic layers (MOLs) can efficiently accelerate mass transport/electron transfer and create abundant readily accessible active sites to ensure high activity in various catalytic reactions[19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34]. The MOLs can be stabilized by templates or surfactants to reduce the surface energy. These additional auxiliary components usually block the catalytic active sites to hinder efficient mass/charge transfer, severely reducing the catalytic activity. 1.5 nm) by using graphene oxide (GO) as both template and electron mediator In this composite, the conductive support can reduce the surface energy of the ultrathin nanosheets to isolate and stabilize the three-layer MOLs, and can efficiently accelerate electron transfer during the CO2-to-CO conversion, achieving a record high CO yield of 3133 mmol g–1MOL, ca. The conductive support can reduce the surface energy of the ultrathin nanosheets to isolate and stabilize the three-layer MOLs, and can efficiently accelerate electron transfer during the CO2-to-CO conversion, achieving a record high CO yield of 3133 mmol g–1MOL, ca. 34 times higher than that of bulky Co-MOF, much superior to those of all the state-of-the-art MOF and MOL catalysts

Methods

Results

Conclusion