Preparation and application of bimetallic mixed ligand MOF photocatalytic materials

Semiconductor-based photocatalysis attracts wide attention because of its ability to directly utilize solar energy for production of solar fuels, such as hydrogen and hydrocarbon fuels and for degradation of various pollutants. However, the efficiency of photocatalytic reactions remains low due to the fast electron-hole recombination and low light utilization. Therefore, enormous efforts have been undertaken to solve these problems. Particularly, properly engineered heterojunction photocatalysts are shown to be able to possess higher photocatalytic activity because of spatial separation of photogenerated electron-hole pairs. Here, the basic principles of various heterojunction photocatalysts are systematically discussed. Recent efforts toward the development of heterojunction photocatalysts for various photocatalytic applications are also presented and appraised. Finally, a brief summary and perspectives on the challenges and future directions in the area of heterojunction photocatalysts are also provided.

Among the large family of metal-organic frameworks (MOFs), Zr-based MOFs, which exhibit rich structure types, outstanding stability, intriguing properties and functions, are foreseen as one of the most promising MOF materials for practical applications. Although this specific type of MOF is still in its early stage of development, significant progress has been made in recent years. Herein, advances in Zr-MOFs since 2008 are summarized and reviewed from three aspects: design and synthesis, structure, and applications. Four synthesis strategies implemented in building and/or modifying Zr-MOFs as well as their scale-up preparation under green and industrially feasible conditions are illustrated first. Zr-MOFs with various structural types are then classified and discussed in terms of different Zr-based secondary building units and organic ligands. Finally, applications of Zr-MOFs in catalysis, molecule adsorption and separation, drug delivery, and fluorescence sensing, and as porous carriers are highlighted. Such a review based on a specific type of MOF is expected to provide guidance for the in-depth investigation of MOFs towards practical applications.