Metal Oxide-based Functional Materials for Solar Energy Conversion: A Review

Sunlight has a great potential to replace current fossil fuels due to its abundance and environmental merit. Considering the solar energy conversion, metal oxides are extensively studied in dye- sensitized solar cell (DSSC) and solar fuel because of its many advantages, such as chemical stability, suitable band gap structures, and abundance on the Earth. Therefore, it is very important to present an overview of the metal oxides in the solar energy conversion, especially in DSSC and water splitting. The major difference of the present review from other reviews in solar energy conversion is that it mainly focuses on the introduction of binary and ternary metal oxides in solar energy conversion, especially in DSSC and water splitting. The basic principle, new approaches for improved efficiency, and current existing problems in both DSSC and water splitting were discussed in detail. In water splitting part of this review, several methods aimed at producing hydrogen and oxygen, and approaches for visible-light band gap engineering of binary and ternary metal oxides were explained. This review provides important scientific information to the solar energy community and opens up new possibilities in the field.