Photoreduction of CO2 on ZIF-8/TiO2 nanocomposites in a gaseous photoreactor under pressure swing

•A new type of ZIF-8/TiO2 core-shell nanocomposite is designed to facilitate not only CO2 adsorption but also its subsequent photoreduction.•Sequential fluctuation of reactor pressure plays an important role in promoting product desorption and increasing photocatalyst activity.•This study highlights the significance of engineering variables including mass transfer and reactor design in photocatalytic reactions.

A new type of zeolitic imidazolate framework ZIF-8/TiO2 nanocomposites was developed for photocatalytic reduction of CO2 to CH4 and CO in a newly designed photoreactor under intentionally controlled pressure swing. The ZIF-8/TiO2 core-shell structure plays an important role in the adsorption of CO2 by ZIF-8 and subsequent in-situ photocatalytic reduction on TiO2. The introduction of pressure change in the reaction system facilitates the adsorption-desorption process of CO2 and reaction products, which consequently led to improved photoreduction performance. This approach highlights the importance of mass transfer and reactor design for improved photoreduction.

Graphical abstractDownload high-res image (131KB)Download full-size image