Combinatorial Investigation of the Effects of the Incorporation of Ti, Si, and Al on the Performance of α-Fe2O3 Photoanodes

The effect of adding small amounts of Ti, Si, and Al on the photoelectrochemical activity of alpha-Fe2O3 is investigated using a high-throughput combinatorial method. Quantitative ink jet printing is used to pattern iron oxide and dopant precursors onto conductive glass substrates. Subsequent pyrolysis yields a library of doped iron oxide electrodes that are screened for photoelectrolysis activity by immersing in an electrolyte and scanning a laser over the electrodes to map the photocurrent response. When Si and Al are individually added to iron oxide at the levels we studied, the photoelectrolysis activity decreased whereas low levels of Ti addition enhanced the photocurrents. Synergistic effects were observed resulting in enhanced photocurrents when multiple impurities were added to alpha-Fe2O3.