Visible light photocatalytic water splitting utilizes solar energy to convert water into hydrogen and oxygen, offering a promising approach for green hydrogen production and environmental improvement. This method presents a viable alternative to address the current global energy crisis by providing a sustainable and clean energy source. Perovskites have emerged as excellent photocatalysts for visible-light-induced water splitting due to their unique band gaps, crystal structure, and stability, which contribute to efficient clean energy production. In this study, LaNiO3 and La2NiO4 were synthesized via the solution combustion method and characterized using XRD, XPS, SEM, DRS, UPS, and photoluminescence techniques. A solar simulator was employed as a light source for photocatalytic hydrogen evolution studies. La2NiO4 exhibited negligible activity, while palladium-substituted LaNiO3 demonstrated the highest activity, achieving 19.67 mmol g−1 h−1. Moreover, the apparent quantum efficiency (AQE) increased significantly from 2.58 to 30.7%, highlighting its improved ability to convert absorbed photons into useful chemical energy and the synergy between the two phases. This consistent performance over an extended period underscores the robustness of the catalyst in a photocatalytic water-splitting environment. From this work, LaNiO3 emerges as a more stable and efficient photocatalyst compared to the double perovskite La2NiO4. The findings highlight the potential of palladium-substituted LaNiO3 for practical applications in green hydrogen production, providing a viable and sustainable solution to the current global energy crisis.