Soft selective light absorber for efficient photothermal chemical processes in complex reactor geometries

Abstract

Photothermal chemical process is expected to solve the dilemma of fossil energy consumption, but the sunlight irradiated temperatures of reactors are ~200 °C, unable to drive chemical processes. Herein, we have designed a large scale soft selective light absorber by spray-coating the two-dimensional MXene layer on Al foil, which not only has 88% sunlight absorption but also 1/5 infrared radiation by optimizing the thickness of MXene layer. Meanwhile, the excellent flexibility enables soft selective light absorber to encapsulate various chemical process reactors (disc, conical, spiral tube), allowing them to achieve ~400 °C of sunlight irradiated temperatures, more than two times higher than that coated with carbon black powder. Consequently, the three reactors are applied for photothermal gas state reverse water-gas shift reaction, solid state CO 2 desorption, liquid state methanol reforming reaction, which show the >1200 mol g -1 h -1 of CO generation rate, >3 mL h - 1 of CO 2 desorption rate, >300 mmol g -1 h -1 of H 2 generation rate respectively, at least 10 times higher than the reactors coating with carbon black. This work for the first time reports the soft selective light absorber to retrofit chemical process reactors as efficient photothermal reactors, which provides a solid foundation for the revolution of sunlight driven chemical industry.