Metal-Organic Frameworks for Aromatic-Based VOC Decomposition

Metal-organic frameworks (MOFs) are a class of porous materials based on the strong coordinated bonds between inorganic secondary building units (SBUs) and organic linkers to form high-porosity periodic structures. MOFs with tunable pore size, shape, and catalysis active sites recently sparked recognition interest for the design and synthesis of catalysts with the capability to decompose aromatic-based VOCs. In this review, we introduce our viewpoints for the design and synthesis of better MOF-based photocatalysts including (i) methods to enhance the interaction of aromatic-based VOCs with MOFs by controlling micropore size, tuning Lewis acidity of the metal SBUs and/or using linkers bearing electron withdrawal groups; (ii) methods to enhance adsorption/diffusion by synthesizing hierarchical MOFs through defect control, reticular structural design and/or employing the xerogel monoliths to exploit the mesopore between particles for enhancing the adsorption/diffusion; (iii) methods to optimize the band gap by selecting appropriate building block and/or doping with exotic components. Alongside that, design principles and strategies for the development of MOF-based catalysts for thermal decomposition of aromatic-based VOCs are also provided such as (i) the need to improve the thermal stability at high temperature together with a slit pore architecture connected by small windows to prevent the aggregation of active components; and (ii) methods to control the distribution and type of active components in the MOFs' matrix to alter their catalysis performance. We expect our discussion and viewpoints on the design and synthesis of MOFs and MOF-based composites to inspire researchers to design better and more efficient systems for aromatic-based VOC decomposition.