Monolithic NF@ZnO/Au@ZIF-8 photocatalyst with strong photo-thermal-magnetic coupling and selective-breathing effects for boosted conversion of CO2 to CH4

Abstract

Gas adsorption/desorption process and conversion efficiency of solar energy are crucial to photocatalytic CO2 conversion. Here, we report the synthesis of a metal-organic-framework based monolithic NF@ZnO/Au@ZIF-8 photocatalyst that can simulate the respiratory process to accelerate adsorption of CO2 and desorption of CH4 during the photocatalytic reaction. Particularly, this selective-breathing monolithic photocatalyst could coupling external magnetic field into the photocatalytic process, achieving photo-thermal-magnetic field synergy in the reaction system. Upon this photo-thermal-magnetic coupling, the temperature of surface reaction could be elevated to about 180 °C, leading to a drastically improved charge transfer behavior and the significantly increased breathing efficiency. The yield of CH4 over the selective-breathing monolithic NF@ZnO/Au@ZIF-8 photocatalyst reaches 270.02 μmol/g with a high stability and a high selectivity up to 89.72%. This study provides an ideal approach for the design of monolithic catalysts not only with balanced gas adsorption-desorption property, but also endowed with multi-field coupling ability.