In solar energy harvesting research, there is growing interest in the study of photoelectrochemical (PEC) properties of the following classes of semiconductor materials: metal oxides and silicon-based compounds. The motivation is that such materials are being successfully used as photoelectrode in PEC cells. Special attention has been given to the wide band gap materials. This review discusses, from the material science perspective, the recent literature relating to two wide band gap semiconductor materials: one metal oxide, titanium dioxide (TiO2), and one silicon-based compound, silicon carbide (SiC). Emphasis is placed on TiO2 and SiC thin films for PEC applications. Materials characteristics, synthesis methods and recent photocatalytic applications are presented. Finally, the interesting effect of the efficiency increase of PEC devices developed from a hetero-junction of TiO2 and SiC is discussed.