Enhanced Visible-Light-Driven Hydrogen Production through MOF/MOF Heterojunctions

Abstract

A strategy for enhancing the photocatalytic performance of MOF-based systems (MOF: metal−organic framework) is developed through the construction of MOF/ MOF heterojunctions. The combination of MIL-167 with MIL-125-NH 2 leads to the formation of MIL-167/MIL-125-NH 2 heterojunctions with improved optoelectronic properties and efficient charge separation. MIL-167/MIL-125-NH 2 outperforms its single components MIL-167 and MIL-125-NH 2 , in terms of photocatalytic H 2 production (455 versus 0.8 and 51.2 μmol h −1 g −1 , respectively), under visible-light irradiation, without the use of any cocatalysts. This is attributed to the appropriate band alignment of these MOFs, the enhanced visible-light absorption, and long charge separation within MIL-167/MIL-125-NH 2 . Our findings contribute to the discovery of novel MOF-based photocatalytic systems that can harvest solar energy and exhibit high catalytic activities in the absence of cocatalysts.

Self-Assembly of a 3D Hollow BiOBr@Bi-MOF Heterostructure with Enhanced Photocatalytic Degradation of Dyes

“…Photocatalytic degradation has been considered to be an effective and promising method for removing organic dyes from industrial wastewater, − where the separation of photogenerated charge carriers and the effective absorption of dye molecules are crucial in the degradation processes . Thanks to their strong ability to capture dye molecules, high surface area, flexible skeleton structure, diversified functions, and intriguing tailorable features, metal–organic frameworks (MOFs) seem to be a promising porous photocatalyst in realizing the efficient degradation of dyes, − while MOFs themselves exhibit very poor transmission/separation efficiency of photogenerated charge carriers and limited visible light adsorption ability. − Consequently, several efficient inorganic semiconductor/MOF-based heterojunctions, such as TiO 2 @MOF, CdS–NRs/MOF, g-C 3 N 4 /MOF, and BiOBr/MIL-53­(Fe), − were developed to significantly improve their photocatalytic performance. Normally, the MOF-based heterostructure was fabricated by the postsynthesis method, where the semiconductors (TiO 2 , CdS, g-C 3 N 4 ) were directly introduced into the metal ions and ligand solution. − The problem was that the interface between inorganic semiconductors and MOFs lacked an effective combination.…”

A well-defined S-g-C3N4/Cu–NiS heterojunction interface towards enhanced spatial charge separation with excellent photocatalytic ability: synergetic effect, kinetics, antibacterial activity, and mechanism insights

“…[13][14][15][16][17] In addition to these approaches, engineering a heterointerface has been acknowledged as an essential way of permitting enhanced photocatalytic performance. 18,19 g-C 3 N 4 is one of the most persistent allotropes of carbon commonly possessing a 2D structure with a bandgap value of 2.72 eV. g-C 3 N 4 has gained excessive research consideration as a probable photocatalyst by scientists for a variety of applications.…”

“… 13–17 In addition to these approaches, engineering a heterointerface has been acknowledged as an essential way of permitting enhanced photocatalytic performance. 18,19 …”

MOFs-Derived Zn-Based Catalysts in Acetylene Acetoxylation

“…MOFs are crystalline nanoporous materials with a framework structure composed of transition metal ions and organic ligands [ 18 ], with the metal components dispersed one by one through organic ligands. On account of the large specific surface area, abundant pore structure, and surface defects of MOFs, MOFs have become a research hotspot in the fields of gas storage, gas adsorption, separation, sensors, drug controllable release, and catalytic reactions [ 19 , 20 , 21 , 22 , 23 , 24 , 25 ]. Because of their excellent chemical and thermal stability, MOFs are also used as a template or precursor for the preparation of porous carbon materials or metal composite materials [ 26 ].…”