Coupling the full solar spectrum with a two-step thermo-electrolytic cycle for efficient solar hydrogen production

•A thermodynamic model coupling the full solar spectrum with a two-step thermo-electrolytic cycle was established.•Solar spectral splitting at an adjustable cut-off wavelength allows a flexible allocation of the solar spectrum.•Solar-to-H2 efficiency can be significantly improved by the introduction of spectral splitting.•Effects of various reaction conditions and oxygen carrier properties were investigated.•The model can be extended to other solar-driven hydrogen production processes with hybrid driving forces.