A core/shell approach that utilizes a high-surface area conducting core and an outer semiconductor shell is exploited to prepare p-type dye-sensitized solar energy cells that operate with a minimal applied bias. Photocathodes were prepared by coating thin films of nanocrystalline indium tin oxide with a 0.8 nm Al2O3 seeding layer, followed by the chemical growth of nonstoichiometric strontium titanate. Films were annealed and sensitized with either a porphyrin chromophore or a chromophore−catalyst molecular assembly consisting of the porphyrin covalently tethered to the ruthenium complex. The sensitized photoelectrodes produced cathodic photocurrents of up to −315 μA/cm2 under simulated sunlight (AM1.5G, 100 mW/cm2) in aqueous media, pH 5. The photocurrent was increased by the addition of regenerative hole donors to the system, consistent with slow interfacial recombination kinetics, an important property of p-type dye-sensitized electrodes.
Reilly, C. E.; Dillon, R. J.; Nayak, A.; Brogan, S.; Moot, T.; Brennaman, M. K.; Lopez, R.; Meyer, T. J.; Alibabaei, L. Dye-Sensitized Nonstoichiometric Strontium Titanate Core-Shell Photocathodes for Photoelectrosynthesis Applications. ACS Appl. Mater. Interfaces 2021, 13 (13) 15261-15269. https://doi.org/10.1021/acsami.1c00933