Aligned porous carbon film with ultralow loadings of Pt single atoms and clusters for high-current-density hydrogen generation

The development of electrocatalysts toward the hydrogen evolution reaction (HER) with high-current-density capability is critical for the practical application of water splitting for hydrogen production. While Pt-based materials are regarded as the most efficient HER catalysts, they suffer from scarcity and high price. Thus, it is of vital importance to lower the loading of Pt while maintaining high activity. Here, we report the fabrication of a monolithic aligned porous carbon film electrode co-modified with Pt single atoms and Pt nanoclusters (Pt SA/NC-AF) containing ultralow Pt content (0.038 wt.%) via a facile electrochemical deposition process. Benefiting from the aligned porous structure of the carbon film and the high exposure of the Pt species, the optimized Pt SA/NC-AF electrode exhibits outstanding HER performance in 0.5 M H₂SO₄ with exceptional intrinsic activity (turnover frequency (TOF) = 904.9 s⁻¹ at η = 100 mV) and ultrahigh mass activity (888.6 A·mg_Pt⁻¹ at η = 100 mV). Further, it can deliver an industrially relevant current density of 1,000 mA·cm⁻² at an overpotential as low as 139 mV. This work provides a feasible avenue for the rational design of metal single-atom and nanocluster catalysts and additionally promotes the application of ultralow-loading noble metal-based catalysts in high-rate hydrogen production.