In Situ Fabrication of Porous MOF/COF Hybrid Photocatalysts for Visible-Light-Driven Hydrogen Evolution

Abstract

Construction of porous metal–organic framework (MOF)/covalent organic framework (COF) hybrid photocatalysts for enriched structures and unprecedented properties is still a great challenge but highly desirable. Herein, a new series of Cu3(HHTP)2-MOF/Tp-Pa-1-COF hybrids with different MOF content are successfully fabricated. The as-prepared MOF/COF hybrids exhibit intimate interaction based on the coordination of Cu ions with the carbonyl oxygen and enamine nitrogen groups in Tp-Pa-1. The integrated conductive Cu3(HHTP)2 is able to act as an excellent electron extractor instead of noble metal cocatalysts to significantly promote the charge transfer and inhibit the recombination of photogenerated electron–hole pairs. As a results, the optimized photocatalyst with Cu3(HHTP)2:Tp-Pa-1 ratio of 1:15 achieves the highest hydrogen evolution rate of 1.76 mmol·h–1·g–1 under visible-light irradiation, which is about 93 times higher than that of the pure Tp-Pa-1 and even slightly higher than that of the Tp-Pa-1 with Pt (3 wt %) as a cocatalyst.

Boosting photocatalytic hydrogen evolution of covalent organic frameworks by introducing 2D conductive metal–organic frameworks as noble metal-free co-catalysts

“…43 Therefore, the performance of the Tp-Pa-2/Cu 3 (HHTP) 2 (3 : 1) composite is slightly improved in the second cycle which can be attributed to the increased Cu + content, which might be beneficial to inhibiting the recombination of photogenerated carriers and accelerate the kinetics of hydrogen evolution. 21…”

“…43 Therefore, the performance of the Tp-Pa-2/Cu 3 IJHHTP) 2 (3 : 1) composite is slightly improved in the second cycle which can be attributed to the increased Cu + content, which might be beneficial to inhibiting the recombination of photogenerated carriers and accelerate the kinetics of hydrogen evolution. 21 To further explore the reasons for the improvement on the photocatalytic activity of the composites compared to that of the pure materials, PL emission spectra and time-resolved PL decay were measured to investigate the charge-carrier separation and transfer in the composite materials. It can be easily observed in Fig.…”

“…9,10 More recently, COF-based photocatalysts have achieved obvious success, exhibiting excellent visible-light-driven hydrogen evolution. [11][12][13][14][15][16][17][18][19][20][21] For example, Lan et al 11 reported that Tp-Pa-1-COF/UiO-66-NH 2 hybrid materials exhibited an excellent H 2 production rate of 23.41 mmol h −1 g −1 in the presence of Pt as a co-catalyst under visible-light irradiation. Cooper et al 22 introduced a rigid and planar dibenzo[b,d]thiophene sulfone (DBTS) moiety into a COF and successfully prepared a more effective π-π stacking FS-COF, which showed a steady photochemical hydrogen evolution rate of 10.1 mmol h −1 g −1 with a sacrificial electron donor and Pt co-catalyst.…”

Metalated covalent organic frameworks: from synthetic strategies to diverse applications

“…The more relevant literature on metalated COF-based photocatalysts for the HER is summarized in Table 6 to facilitate comparison of their properties and to provide information for designing new materials. 204,250,351,352,364,376,580,581,583,585,586,591,592 3.4.2. Photocatalytic CO 2 reduction.…”

Porous organic polymers for drug delivery: hierarchical pore structures, variable morphologies, and biological properties

“…POPs have low mass as they are mainly composed of light elements (C, H, O, and N). 24 Based on the differences in their synthetic methods and structures, POPs can be divided into covalent organic frameworks (COFs), 25,26 hypercrosslinked polymers (HCPs), 27,28 polymers of intrinsic microporosity (PIMs), 29,30 porous aromatic frameworks (PAFs), 31,32 and conjugated microporous polymers (CMPs). 33,34 HCPs, PIMs, PAFs, and CMPs are amorphous, whereas COFs are highly crystalline.…”