Semiconductors with small band gaps (2O to O2(g) and reduction of H2O or H2O and CO2 to fuels. We report herein the stabilization of np+-Si(100) and n-Si(111) photoanodes for over 1200 h of continuous light-driven evolution of O2(g) in 1.0 M KOH(aq) by an earth-abundant, optically transparent, electrocatalytic, stable, conducting nickel oxide layer. Under simulated solar illumination and with optimized index-matching for proper antireflection, NiOx-coated np+-Si(100) photoanodes produced photocurrent-onset potentials of -180 ± 20 mV referenced to the equilibrium potential for evolution of O2(g), photocurrent densities of 29 ± 1.8 mA cm-2 at the equilibrium potential for evolution of O2(g), and a solar-to-O2(g) conversion figure-of-merit of 2.1%.
ASJC Scopus subject areas
- Materials Science(all)