New cubic perovskites for one- and two-photon water splitting using the computational materials repository

Abstract

A new efficient photoelectrochemical cell (PEC) is one of the possible solutions to the energy and climate problems of our time. Such a device requires development of new semiconducting materials with tailored properties with respect to stability and light absorption. Here we perform computational screening of around 19 000 oxides, oxynitrides, oxysulfides, oxyfluorides, and oxyfluoronitrides in the cubic perovskite structure with PEC applications in mind. We address three main applications: light absorbers for one-and two-photon water splitting and high-stability transparent shields to protect against corrosion. We end up with 20, 12, and 15 different combinations of oxides, oxynitrides and oxyfluorides, respectively, inviting further experimental investigation.

Solar fuels photoanode materials discovery by integrating high-throughput theory and experiment

“…Forty years of experimental research has yielded just 16 metal-oxide photoanode compounds with band-gap energy in the desirable 1.2-2.8-eV range that strongly overlaps with the solar spectrum. Prior high-throughput computational screening studies have yet to expand this list (6,7,13), in part due to quantitative limitations in predictability of the electronic structure--especially band-gap energy, E g , and the valence band maximum (VBM) energy, E VBM --from the chemical composition and crystal structure. Our integration of ab initio theory with high-throughput experiments has yielded a most prolific materials discovery effort, as demonstrated by the identification of 12 water oxidation photoelectrocatalysts in the target band-gap range, including our recently reported 4 copper vanadates (14) and 8 additional metal vanadates reported here.…”

Bandgap Engineering of Double Perovskites for One- and Two-photon Water Splitting

“…The projected DOS for the Hf-d and Sn-s/p orbitals change when considering the two separated structures compared to the double perovskite and they show peaks, in particularly Hf and Sn, in the double perovskite that are not present in the cubic ones. The conduction band wavefunctions for the systems follow the densities: the d-like wavefunction present around Hf in the BaHfO 3 disappears in favor of a more intense s-like wavefunction around Sn in the BaHfSrSnO 6 . The highest occupied molecular orbital (HOMO) is in general formed by oxygen 2p states and the lowest unoccupied molecular orbital (LUMO) by states of the B-ions.…”

“…In contrast with this, the elements in the A-ion positions do not affect the size of the resulting bandgap very much. The reason for the opening of the bandgap compared to the average value is a strong hybridization between the p-and d-metals in the B-ion positions as shown in Figure 3 where we plot the projected density of states (DOS) for three systems: BaHfO 3 , SrSnO 3 , and their combination BaHfSrSnO 6 . The projected DOS for the Hf-d and Sn-s/p orbitals change when considering the two separated structures compared to the double perovskite and they show peaks, in particularly Hf and Sn, in the double perovskite that are not present in the cubic ones.…”

“…Many efforts we have been recently made to design new materials using computational tools, for example screening for organic photovoltaics, [2][3] inorganic scintillators 4 and bandgap engineering. 1,[5][6][7] In previous works, 1,6 we addressed one of the most pressing problems of our time, i.e. the development of sustainable energy technology, focusing on the photoelectrochemical conversion of water into hydrogen and oxygen using visible solar light considering both the one-and twophoton water splitting processes.…”

Methods of photoelectrode characterization with high spatial and temporal resolution

“…Given recent advancements in both high-performance computing and computational algorithms, opportunities for using modeling and simulation as predictive tools for PEC studies are expanding. 17,18,[178][179][180][181] Accordingly, it is becoming increasingly evident that modeling and characterization efforts require tighter integration as PEC research activities move forward. Fig.…”