Computational-Guided Design of Photoelectrode Active Materials for Light-Assisted Energy Storage

The design of a novel photoelectric integrated system is considered to be an efficient way to utilize and store inexhaustible solar energy. However, the mechanism of photoelectrode under illuminate conditions is still unclear. Density functional theory (DFT) provides standardized analysis and becomes a powerful way to explain the photoelectrochemical mechanism. Herein, the feasibility of four metal oxide configurations as photoelectrode materials by using a high throughput calculation method based on DFT are investigated. According to the photoelectrochemical properties, band structure and density of states are calculated, and the intercalate/deintercalate simulation is performed with adsorption configuration. The calculation indicates that the band gap of Fe2CoO4 (2.404 eV) is narrower than that of Co3O4 (2.553 eV), as well as stronger adsorption energy (-3.293 eV). The relationship between the electronic structure and the photoelectrochemical performance is analyzed and verified according to the predicted DFT results by subsequent experiments. Results show that the Fe2CoO4 photoelectrode samples exhibit higher coulombic efficiency (97.4%) than that under dark conditions (94.9%), which is consistent with the DFT results. This work provides a general method for the design of integrated photoelectrode materials and is expected to be enlightening for the adjustment of light-assisted properties of multifunctional materials.

Automated summary

In this study, the feasibility of four metal oxide configurations as photoelectrode materials was investigated through density functional theory (DFT) analysis and high throughput calculation method. The calculation results showed that the Fe2CoO4 photoelectrode samples had a narrower band gap and stronger adsorption energy compared to Co3O4 photoelectrode samples. Experimental results verified the relationship between electronic structure and photoelectrochemical performance, revealing that Fe2CoO4 photoelectrode samples exhibited significantly higher coulombic efficiency under illuminated conditions compared to dark conditions. This research provides a general method for the design of integrated photoelectrode materials and is enlightening for the adjustment of light-assisted properties of multifunctional materials.