Comparative Studies of Oxygen-Free Semiconductors in Photocatalytic CO₂ Reduction and Alcohol Degradation

Commercially available α-SiC, β-SiC, GaN, ZnTe and self-synthesized g-C₃N₄ were investigated in a comparative study regarding their photocatalytic capabilities in CO₂ reduction and alcohol degradation. Under reproducible high-purity solid-gas conditions none of the tested materials promoted CO₂ reduction using H₂O as proton donor, although TiO₂ P25 has been shown to produce significant amounts of CH₄ under similar conditions. Replacing H₂O with 2-propanol led to hydrocarbon formation which could solely be attributed to alcohol degradation while no CO₂ reduction took place.