X-ray Photospectroscopy and Electronic Studies of Reactor Parameters on Photocatalytic Hydrogenation of Carbon Dioxide by Defect-Laden Indium Oxide Hydroxide Nanorods

In the study reported herein, glovebox-protected X-ray photoelectron spectroscopy (XPS) and in situ Hall charge carrier measurements provide new insights into the surface physical chemistry of gaseous H-2, CO2, and H-2+CO2 combined with nanostructured In2O(3-x)(OH)(y) nanorods, which ensue under photochemical and thermochemical operating conditions. Heterolytic dissociation of H-2 in H-2-only atmosphere appears to occur mainly under dark and ambient temperature conditions, while the greatest amount of OH shoulder expansion in H-2+CO2 atmosphere appears to mainly occur under photoilluminated conditions. These results correlate with those of the Hall measurements, which show that the prevalence of homolytic over heterolytic dissociation at increasing temperatures leads to a steeper rate of increase in carrier concentrations; and that H-2 adsorption is more prevalent than CO2 in H-2+CO2 photoillumination conditions.