title: Nanonet-based hematite heteronanostructures for efficient solar water splitting.
abstract: We report the highest external quantum efficiency measured on hematite (α-Fe(2)O(3)) without intentional doping in a water-splitting environment: 46% at λ = 400 nm. This result was enabled by the introduction of TiSi(2) nanonets, which are highly conductive and have suitably high surface areas. The nanonets serve a dual role as a structural support and an efficient charge collector, allowing for maximum photon-to-charge conversion. Without the addition of any oxygen-evolving catalysts, we obtained photocurrents of 1.6 and 2.7 mA/cm(2) at 1.23 and 1.53 V vs RHE, respectively. These results highlight the importance of charge transport in semiconductor-based water splitting, particularly for materials whose performance is limited by poor charge diffusion. Our design introduces material components to provide a dedicated charge-transport pathway, alleviating the reliance on the materials' intrinsic properties, and therefore has the potential to greatly broaden where and how various existing materials can be used in energy-related applications.
authors.affiliation: Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, Massachusetts 02467, USA.
authors.forename: Yongjing
authors.initials: Y
authors.lastname: Lin
authors.forename: Sa
authors.initials: S
authors.lastname: Zhou
authors.forename: Stafford W
authors.initials: SW
authors.lastname: Sheehan
authors.forename: Dunwei
authors.initials: D
authors.lastname: Wang
mesh_terms: D005290:Ferric Compounds / Q000737:chemistry*; D049329:Nanostructures / Q000737:chemistry*; D010316:Particle Size; D011789:Quantum Theory; D017640:Silicates / Q000737:chemistry*; D013499:Surface Properties; D014025:Titanium / Q000737:chemistry*; D014867:Water / Q000737:chemistry*
chemical_list: D005290:Ferric Compounds; D017640:Silicates; D014867:Water; C103828:titanium silicide; C000499:ferric oxide; D014025:Titanium