Making porous materials respond to visible light

Porous materials like metal-organic frameworks are crucial matrixes to construct heterogeneous catalysts for energy conversion. To maximize the efficiency, it is desirable that the properties of porous materials can be tuned on demand in different catalysis stages. As adsorption is the initial step of catalysis, the studies on achieving controllable adsorption processes contribute to the development of smart porous catalysts. Recently, the emerging photoresponsive adsorbents have endowed adsorption and desorption processes with responsiveness to the remote stimuli, bringing innovation to the typical adsorptive cycles. In this Perspective, we trace the origin and development of photoresponsive adsorbents, and the features of photoresponsive adsorbents are introduced in detail. The strategies of introducing photoresponsive components to porous materials and ingenious utilization of their photoresponsiveness are highlighted. The future opportunities and critical challenges as well as the potential applications in energy conversion are also discussed.