AbstractDesign of composite semiconductor nanostructures with proper band alignment for efficient charge separation and carrier transport has been at the center of research for photoelectrochemical water splitting. This work demonstrates the deposition of a NiFe2O4 @Fe2O3 core-shell nanostructured film sensitized with CdS to form a ternary heterojunction for cascade type electron transfer. The hematite nanostructures were grown by hydrothermal approach through dipping into a solution of Nickel Nitrate yielded anchoring of Ni2+ ions on the outer surface. The films were then annealed at 650 0C for the diffusion of Ni2+ ions into the hematite lattice which forms core-shell NiFe2O4 @Fe2O3 heterojunction. The films were further sensitized with CdS nanoparticles deposited by a hydrothermal approach to form the final ternary heterojunction photoanode. Several different nanostructures were grown and the effect of crystal facet tailoring was observed on Ni loading and photoelectrochemical performance. The photoelectrochemical measurements were carried out using a potentiostat under 100 mW/cm2 light source (150W Xenon Lamp) with Pt counter electrode and 0.5 M Na2S and 0.5 M Na2SO3 electrolyte. A current density of 3.47 mA/cm2 was observed at 1.23 V (vs Ag/AgCl). An Applied Bias to Photocurrent Efficiency (ABPE) of 1.8 % photoconversion efficiency was observed using the fabricated electrodes at 0.288V (vs Ag/AgCl).
Strain-tunable band alignment and band gap of GaSe/WTe2 heterojunction for water splitting and light-emitting
