Photoelectrochemical Hydrogen Production in Alkaline Solutions Using Cu₂O Coated with Earth‐Abundant Hydrogen Evolution Catalysts

Abstract

Additional experimental details:All manipulations were carried out under atmospheric conditions, unless otherwise mentioned. All reagents were purchased from commercial sources and used without further purification. Millipore deionized water 18.2 M was used to prepare all the solutions. All electrochemical measurements were done using an Autolab potentiostat/galvanostat.A three-electrode configuration under front-side simulated AM 1.5 G solar illumination was used for photoelectrochemical hydrogen evolution measurements. Pt wire was used as the counter electrode and an Ag/AgCl (KCl sat.) electrode was used as the reference electrode. Different electrolyte buffer solutions were used at different pH values and were referenced in the text by the pH value unless otherwise mentioned. 1.0 M KOH (Merck) solution was used as pH 13.6 electrolyte and 1.0 M H 2 SO 4 (Merck, 95-97%) was used as pH 0. The pH 4.0 solution consists of 1.0 M potassium hydrogen phosphate (Sigma,

Transparent Cuprous Oxide Photocathode Enabling a Stacked Tandem Cell for Unbiased Water Splitting

“…[28] Furthermore, catalysts for water oxidation are generally more efficient in alkaline solutions, for which there are several desirable Earth-abundant candidates. [21] At present, we found this TiO 2 overlayer approach to be insufficiently stable in alkaline conditions to allow a demonstration extended operation, but further study in this direction is ongoing, [29] since a stable and efficient photocathode in alkaline solution would be highly desirable.…”

Solar Hydrogen Production by Amorphous Silicon Photocathodes Coated with a Magnetron Sputter Deposited Mo2C Catalyst

“…Moreover, TiO 2 -protected Cu 2 O photocathode had similar stability in base. 31 To further probe the origin of deactivation, the a-Si/Mo 2 C photocathodes after 1, 2, and 5 h of operation were analyzed by XPS. Mo 2 C was still found on the photocathodes, but its amount decreased with time.…”

Enhanced photocathodic behaviors of Pb(Zr0.20Ti0.80)O3 films on Si substrates for hydrogen production

“…Although the applications of some p-type oxide semiconductors (e.g., CaFe 2 O 4 , p-LaFeO 3 /n-Fe 2 O 3 , Rhdoped SrTiO 3 ) in PEC devices have been reported, they are still faced with challenges such as a low hydrogen generation rate since the photocurrent densities at 0 V vs. RHE were usually less than 100 lA/cm 2 . 21-23 Paracchino et al 24 and Morales-Guio et al 25 reported highly active p-type Cu 2 O photocathode with proper catalysts for solar H 2 production. 6.3 mA/cm 2 of photocurrent at 0 V vs. RHE and 0.5 V vs. RHE of on-set potential were obtained under 100 mW/cm 2 simulated solar illumination in 1 M KOH.…”