Photoelectrochemical (PEC) water splitting is attracting significant research interest in addressing sustainable development goals in renewable energy. Current state-of-the-art, however, cannot provide photoanodes with simultaneously high efficiency and long-lasting lifetime. Here, large-scale NiFe oxyhydroxides-alloy hybridized co-catalyst layer that exhibits an applied bias photon-to-current efficiency (ABPE) of 4.24% in buried homojunction-free photoanodes and stability over 250 h is reported. These performances represent an increase over the present highest-performing technology by 408% in stability and the most stable competitor by over 330% in efficiency. These results originate from a previously unexplored mechanism of light-induced atomic reconfiguration, which rapidly self-generates a catalytic-protective amorphous/crystalline heterostructure at low biases. This mechanism provides active sites for reaction and insulates the photoanode from performance degradation. Photon-generated NiFe oxyhydroxides are more than 200% higher than the quantity that pure electrocatalysis would otherwise induce, overcoming the threshold for an efficient water oxidation reaction in the device. While of immediate interest in the industry of water splitting, the light-induced NiFe oxyhydroxides-alloy co-catalyst developed in this work provides a general strategy to enhance further the performances and stability of PEC devices for a vast panorama of chemical reactions, ranging from biomass valorization to organic waste degradation, and CO2-to-fuel conversion.
Keywords: efficiency; photoelectrochemical devices; solar fuel production; solar water oxidation; stability.
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