The pursuit of efficient and sustainable hydrogen production is essential in the fight against climate change. One important method for achieving this is the electrolysis of water, particularly through the oxygen evolution reaction (OER). Recent studies indicate that trimetallic layered double hydroxides (LDHs) can enhance OER performance compared to bimetallic LDHs. This improvement occurs because the third cation alters the electronic structures of the other two cations, thereby increasing the intermediates' binding energies and enhancing electrical conductivity. This study proposes an approach enabling the modulation of the electronic structures of all three cations involved in the synthesis of the trimetallic LDHs. It suggested intercalating sodium dodecyl sulfate (SDS) into the interlayer of the trimetallic NiFe-La-LDH. A successful intercalation of SDS has been confirmed through the XRD, FT-IR, EDS, and XPS. This has expanded the interlayer distance which was beneficial for the electrical conductivity. Furthermore, SDS generated sulphur, which modulated the electronic structures of all three cations enriching the active sites and improving electrical conductivity and OER performance compared to its counterparts. This approach is beneficial: 1. The interlayer can be further enlarged by using different doping ratios of SDS. 2. Sulphur can enrich the active sites and improve the OER performance.