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 (Pm3¯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.