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 H₂, CO₂, and H₂+CO₂ combined with nanostructured In2O(3-x)(OH)y nanorods, which ensue under photochemical and thermochemical operating conditions. Heterolytic dissociation of H₂ in H₂-only atmosphere appears to occur mainly under dark and ambient temperature conditions, while the greatest amount of OH shoulder expansion in H₂+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 H₂ adsorption is more prevalent than CO₂ in H₂+CO₂ photoillumination conditions.