Fig. 2: Relating photo-charge and surface reactivity with photo-intensities.
The photo-current trend with increasing photo-intensities; photocurrent changes with increasing flow concentration of 1 sccm of H2 and 1 sccm of CO2 in argon; glovebox protected XPS measurements of In2O3−x(OH)y nanorods coated on planar and cylindrical rod geometries after reactions in dark and photo-illuminated conditions at 1:1 H2:CO2 pressure ratio atmosphere at various temperatures. a The photocurrent trend of the coated planar substrate under increasing photo-intensities shows a sharp rise at low photo-intensities below 100 mW/cm2 and semi-saturation at higher photo-intensities. b Photocurrent increase with increasing H2 + CO2 gas concentrations and with increasing photo-intensities. c, d The O1s spectra of In2O3−x(OH)y nanorods on a planar surface at 150 °C and 200 °C post dark and photo-illumination of one hour in H2 + CO2 atmosphere (inset). The O1s spectrum of In2O3−x(OH)y nanorods as prepared on a planar surface, after an hour in a vacuum. The species with FWHM widths of less than 1.3 eV are oxide lattice, oxygen vacancy, and OH groups. e O1s spectra under H2 + CO2 at 200 °C under increasing photo-intensities of 1 h. The OH shoulder increases significantly with increasing photo-intensities. f The oxide species of lattice oxide, oxygen vacancies, OH, and H+OH species are seen for the sample under the highest photo-intensity of 125.5 mW/cm2. g The O1s spectra of the In2O3−x(OH)y nanorods coated on a rod waveguide after photo-illumination at 200 °C for 1 h, under increasing photo-intensities. h The O1s shoulder ratio of the In2O3−x(OH)y rods on planar substrates and rod waveguides as a function of increasing photo-intensities.
