Investigation on multifunctional Au/TiO2@n-octadecane microcapsules towards catalytic photoreforming hydrogen production and photothermal conversion

Combining solar energy utilization and hydrogen production is an ideal model for renewable energy development. Especially the conversion of broad-spectrum solar energy into chemical energy of hydrogen and thermal energy can enrich solar energy storage methods. Herein, novel multifunctional Au/TiO 2 @n-octadecane microcapsules with core-shell structure were design and synthesized by wet chemical reduction and electrostatic adsorption self-assembly methods for photothermal hydrogen production and thermal storage . The results showed that microencapsulation of photothermal catalysts could provide an effective reaction area and excellent dispersion stability , where hydrogen production and light to hydrogen efficiency were increased in the 43% and 0.3% respectively, compared to the nanoparticle suspension system. Based on the recorded temperature variations caused by the photothermal effect, the calculated photothermal conversion efficiency and specific absorption rate of Au/TiO 2 @n-octadecane was 25.01% and 277% higher than that of Au/TiO 2 suspension. The proposed hydrogen production and thermal storage method via multifunctional microcapsules might shed some light on the study of improving full-spectrum energy conversion efficiency of solar energy.