Hydrogen production from bio-derived biphasic photoreforming over a raspberry-like amphiphilic Ag2O-TiO2/SiO2 catalyst

Photoreforming of bio-derived liquids is anattractive approach toward sustainable H-2 production. Although a large number of bio-liquids are thermodynamically feasible for photocatalytic hydrogen production, few of them have been involved in this process due to their water insoluble nature. To achieve and promote the efficiency of photoreforming hydrogen production in bio-derived biphasic system, the Pickering interfacial catalysis was established over an amphiphilic Ag2O-TiO2/SiO2 catalyst. In this case, the Ag2O-TiO2/SiO2 sample was synthesized by means of an electrostatic self-assembly method by surface charge regulation of SiO2 and the surface hydrophobic modification of Ag2O-TiO2/SiO2 particles using a Pickering emulsion method. As shown in the results, the amphiphilic Ag2O-TiO2/SiO2 particles were observed to successfully stabilize the bio-octanol/water emulsion. Even the complex structure and surface modification slightly reduce the light absorption efficiency and specific surface area of the catalyst, the hydrogen yield was greatly promoted over Ag2O-TiO2/SiO(2 )compared to that of bare TiO2, Ag2O-TiO2 and TiO2/SiO2. It was also discovered that the cyclic hydrogen production performance can be improved by simple re-emulsification. The effect of bio-octanol concentration for photoreforming was studied by a Langmuir-Hinshelwood-type kinetic model, and the reaction rate constant and biooctanol adsorption constant were obtained. This study shows that photocatalyst after effective surface amphiphilic modification could provide a prospective approach for the hydrogen production from a bio-derived oil/ water biphasic system under solar light.