Open Hollow Nut-like Co–PtSA Decorated with CoPt@C for Enhanced Hydrogen Evolution Reaction

Constructing an efficient open hollow nut-like Co-MOF/Pt-based electrocatalyst via a partial etching strategy remains challenging. In this study, a novel concurrent thermal polymerization-etching strategy is introduced to prepare a unique open hollow nut-like Co-PtSA decorated with a CoPt@C layer electrocatalyst (denoted as Co-PtSA/CoPt@C), exhibiting outstanding hydrogen evolution reaction performance. In Co-PtSA/CoPt@C, the distinctive open hollow nut-like Co-PtSA structure is encapsulated within a CoPt@C layer. The CoPt@C layer consists of CoPt@CNTs and a CoPt@C core-shell. Electrochemical tests demonstrate that Co-PtSA/CoPt@C exhibits remarkable catalytic performance, requiring only 13 mV of overpotential in 1 M KOH to achieve a current density of 10 mA cm-2. Additionally, the turnover frequency of Co-PtSA/CoPt@C reaches 0.169 s-1 at η = 50 mV, 0.466 s-1 at η = 100 mV, and 1.33 s-1 at η = 200 mV, surpassing the performance of commercial 20% Pt/C. In addition, the adsorption Gibbs free energy for hydrogen on Co-PtSA/CoPt@C is notably low, with a value of -0.65 eV, which promotes efficient H2 formation.