Review—Copper Oxide-Based Ternary and Quaternary Oxides: Where Solid-State Chemistry Meets Photoelectrochemistry

This review article addresses areas where solid-state chemistry concepts can contribute to the on-going search for a "magic bullet" inorganic semiconductor that can efficiently split water or reduce CO 2 . First, a methodology to visualize complex ternary oxide combinations is outlined using 31 examples based on copper in both +1 and +2 oxidation states. Then the synthetic aspects are reviewed followed by a discussion of the structural characteristics. The optoelectronic aspects are considered next, culminating the review with the state-of-the-art in the practical applicability of these materials in solar fuels photogeneration and environmental (e.g., azo dye) remediation.