It is of broad interest to develop emerging photocatalysts with excellent light-harvesting capacity and high charge carrier separation efficiency for visible light photocatalytic hydrogen evolution reaction. However, achieving satisfying hydrogen evolution efficiency under noble metal-free conditions remains challenging. In this study, we demonstrate the fabrication of three-dimensionally ordered macroporous SrTiO₃ decorated with Zn_xCd_1−xS nanoparticles for hydrogen production under visible light irradiation (λ>420 nm). Synergetic enhancement of photocatalytic activity is achieved by the slow photon effect and improved separation efficiency of photogenerated charge carriers. The obtained composites could afford very high hydrogen production efficiencies up to 19.67 mmol·g⁻¹·h⁻¹, with an apparent quantum efficiency of 35.9% at 420 nm, which is 4.2 and 23.9 times higher than those of pure Zn_0.5Cd_0.5S (4.67 mmol·g⁻¹·h⁻¹) and CdS (0.82 mmol·g⁻¹·h⁻¹), respectively. In particular, under Pt-free conditions, an attractive hydrogen production rate (3.23 mmol·g⁻¹·h⁻¹) was achieved, providing a low-cost and high-efficiency strategy to produce hydrogen from water splitting. Moreover, the composites showed excellent stability, and no obvious loss in activity was observed after five cycling tests.