Phase Electronic Structure Tuning via Pt, P–Doped Ni<sub>4</sub>Mo‐Implanted Ti<sub>4</sub>O<sub>7</sub> for Highly Efficient Water Splitting and Mg/Seawater Batteries
Van Hien Hoa, Sampath Prabhakaran, Mai Mai, Huyen Thi Dao, Do Hwan Kim
Abstract
Abstract Fine‐tuning nanoscale structures, morphologies, and electronic states are crucial for creating efficient water‐splitting electrocatalysts. In this study, a method for electronic structure engineering to enhance overall water splitting in a corrosion‐resistant electrocatalyst matrix by integrating Pt, P dual‐doped Ni 4 Mo electrocatalysts onto a Ti 4 O 7 nanorod grown on carbon cloth (Pt, P–Ni 4 Mo–Ti 4 O 7 /CC) is introduced. By optimizing platinum and phosphorus concentrations to 1.18% and 2.42%, respectively, low overpotentials are achieved remarkably: 24 mV at 10 mA cm −2 for the hydrogen evolution reaction and 290 mV at 20 mA cm −2 for the oxygen evolution reaction in 1.0 m KOH. These values approach or surpass those of benchmark Pt–C and IrO 2 catalysts. Additionally, the Pt, P–Ni 4 Mo–Ti 4 O 7 /CC bifunctional electrocatalyst displays low cell potentials across various mediums, maintaining excellent current retention (96% stability after 40 h in mimic seawater at 20 mA cm −2 ) and demonstrating strong corrosion resistance and suitability for seawater electrolysis. As a cathode in magnesium/seawater batteries, it achieves a power density of 7.2 mW cm −2 and maintains stability for 100 h. Density functional theory simulations confirm that P, Pt doping‐assisted electronic structure modifications augment electrical conductivity and active sites in the hybrid electrocatalysts.