The amorphous SrTiO3- crystalline PbS heterojunctions were prepared through different weight percentages of PbS (5 and 10%) to promote the photocatalytic water splitting. The amorphous SrTiO3 exhibits the combination of the hexagonal cone and nanoparticle like morphology. Similarly, the crystalline PbS shows nanoparticle like morphology. The XRD and TEM results further confirm the amorphous SrTiO3-crystalline PbS heterojunction formation. The EDS and XPS analysis confirm the presence of SrTiO3–PbS heterojunction. The SrTiO3–PbS heterojunction inhibits the self-trapped excitons recombination. The formation of amorphous-crystalline heterojunction suppress the electron transfer resistance which effectively reduces the charge carrier recombination. The SrTiO3–PbS (5%) shows efficient photocatalytic hydrogen production of 5.9 mmol g−1h−1 under ultraviolet irradiation.