A two-dimensional Ni-heteroatom-based metal-organic framework (MOF) array was directly grown on C paper (Ni-MOF-A/CP) via one-pot solvothermal reaction. According to the strategy for MOF self-assembly on C paper, Ni-MOFs were also synthesized on Ni foam (Ni-MOF/NF) with different sizes and morphologies. The newly resulting MOFs with ternary (Ni, S, and N) active sites exhibited enhanced activity toward oxygen evolution reaction [e.g., Ni-MOF-A/CP: E(5 mA cm-2) = 333 mV and a low Tafel slope of 80 mV dec-1].