Photocatalytic conversion of solar energy into fine chemicals or renewable fuels is an attractive strategy to achieve sustainable and ecological development. Herein, 2D/2D-3D Ni12P5/ZnIn2S4 (NP/ZIS) heterostructures are prepared via zinc vacancies (VZn) engineering and cocatalyst modification. The NP/ZIS presents efficient reactivity and stability for visible-light-driven photocatalytic splitting of benzyl alcohol into H2 and benzaldehyde at room temperature due to significantly improved charge carrier separation and transportation via the VZn defect level, the downward band bending and the Coulomb attraction. Compared to pure water splitting and individual ZIS, the thermodynamics and kinetics of H2 production over 7% NP/ZIS are enhanced by 15825.6 and 12.2 times, respectively. Notably, NP/ZIS also shows promising capability for photocatalytic CO2 reduction and N2 fixation coupled with organic synthesis. This work offers a practical plane to fabricate efficient photocatalysts and sheds light on promising reaction to simultaneous utilize photoexcited holes and electrons toward solar-to-chemical energy conversion.