TiO2 was deposited using atomic layer deposition (ALD) with a Picosun R200 system. The tetrakis (dimenthylamido) titanium (IV) (TDMAT) (99.999 %, Sigma-Aldrich, Buchs, Switzerland), and Milli-Q water were used as the Ti and O precursors, respectively. The titanium precursor was heated to 85 o C, and the reactor chamber was maintained at 120 o C during deposition. For the preparation of Sb2Se3 photocathodes, 930 cycles were performed to achieve a 50 nm TiO2 layer. A small piece of the silicon wafer was placed beside the samples to check the film's thickness by ellipsometry. The Pt cocatalyst was sputtered onto the surface of the as-fabricated Sb2Se3/TiO2 electrodes using a sputter coater (Safematic CCU-010). The distance between the target and the samples was set to 5 cm. The chamber was purged three times before sputtering. A nominal 2 nm Pt layer was sputtered under an applied current of 10 mA for 100 s in an Ar atmosphere.