Strong Intermixing Effects of LFO(1−x)/STO(x) toward the Development of Efficient Photoanodes for Photoelectrocatalytic Applications

Aiming to improve the photocatalytic properties of transition metal perovskites to be used as robust photoanodes, [LaFeO(3)](1−x)/[SrTiO(3)](x) nanocomposites (LFO(1−x)/STO(x)) are considered. This hybrid structure combines good semiconducting properties and an interesting intrinsic remanent polarization. All the studied samples were fabricated using a solid-state method followed by high-energy ball milling, and they were subsequently deposited by spray coating. The synthesized compounds were demonstrated to possess orthorhombic (Pnma) and cubic (Pm [Formula: see text] m) structures for LFO and STO, respectively, with an average grain size of 55–70 nm. The LFO(1−x)/STO(x) nanocomposites appeared to exhibit high visible light absorption, corresponding to band gaps of 2.17–3.21 eV. Our findings show that LFO(0.5)/STO(0.5) is the optimized heterostructure; it achieved a high photocurrent density of 11 μA/cm(2) at 1.23 V bias vs. RHE and an applied bias photo-to-current efficiency of 4.1 × 10(−3)% at 0.76 V vs. RHE, as demonstrated by the photoelectrochemical measurements. These results underline the role of the two phases intermixing LFO and STO at the appropriate content to yield a high-performing photoanode ascribed to efficient charge separation and transfer. This suggests that LFO(0.5)/STO(0.5) could be a potential candidate for the development of efficient photoanodes for hydrogen generation via photoelectrocatalytic water splitting.