Photo/electro catalytic green hydrogen production promoted by Ga modified CoCuFeO nano catalysts.

The current work concentrates on the fabrication of Ga doped CoCuFeO nanocatalysts via sol-gel auto-combustion (SGA) for the production of green and sustainable source of energy i.e., hydrogen through photocatalytic and electrocatalytic routes. Single-phased cubic crystal structure with Fd3m geometry was observed through XRD patterns. FESEM images show the aggregated and spherical shaped grains with distinct grain boundaries and average grain size of 1.04 and 1.39 μm for the CoCuFeO, and CoCuGaFeO nanomaterials. Soft magnetic behaviour with a coercivity (H) and saturation magnetization (M) of 235.32-357.26 Oe and 54.65-61.11 emu/g was obtained for the produced nanomaterials. The estimation of photocatalytic nature for generating H was conducted using the sacrificial agents i.e., 0.128 M NaS and 0.079 M NaSO. The analysis focused on measuring the maximum H generation was achieved by photocatalysts throughout three consecutive 4-h cycles. Out of all compositions, CoCuGaFeO nanomaterial have the highest photocatalytic activity of 16.71 mmol g. However, the electrocatalytic behaviour of prepared CoCuGaFeO (x = 0.00-0.03) electrocatalysts were determined for HER (Hydrogen evolution reaction) reaction. The overpotential values of CoCuFeO, CoCuGaFeO, CoCuGaFeO, and CoCuGaFeO catalysts at 10 mA cm were -0.81, -0.85, -1.03, and 1.21 V, correspondingly. Thus, at cathode current density of 10 mA/cm, an elevation in overpotential was noted, which indicates that the undoped CoCuFeO (x = 0.00) electrocatalyst have remarkable electrocatalytic HER activity. Consequently, owing to photo/electro catalytic water splitting traits, the prepared catalysts are highly efficient for the green hydrogen generation.