Pt Single-Atoms on Structurally-Integrated 3D N-Doped Carbon Tubes Grid for Ampere-Level Current Density Hydrogen Evolution

To date, the excellent mass-catalytic activities of Pt single-atoms catalysts (Pt-SACs) toward hydrogen evolution reaction (HER) are categorically confirmed; however, their high current density performance remains a challenge for practical applications. Here, a binder-free approach is exemplified to fabricate self-standing superhydrophilic-superaerphobic Pt-SACs cathodes by directly anchoring Pt-SAs via Pt-NxC4-x coordination bonds to the structurally-integrated 3D nitrogen-doped carbon tubes (N-CTs) array grid (denoted as Pt@N-CTs). The 3D Pt@N-CTs cathode with optimal Pt-SACs loading is capable of operating at a high current density of 1000 mA cm-2 with an ultralow overpotential of 157.9 mV with remarkable long-term stability over 11 days at 500 mA cm-2. The 3D super-wettable free-standing Pt@N-CTs possess interconnected vertical and lateral N-CTs with hierarchical-sized open channels, which facilitates the mass transfer. The binder-free immobilization adding to the large surface area and 3D-interconnected open channels endow Pt@N-CTs cathodes with high accessible active sites, electrical conductivity, and structural stability that maximize the utilization efficiency of Pt-SAs to achieve ampere-level current density HER at low overpotentials. A free-standing cathode is fabricated by anchoring atomically-dispersed Pt on 3D N-doped carbon tube grid. The 3D-interconnected vertical and lateral tube grid with openly accessible hierarchical-sized channels and the unique superhydrophilic-superaerphobic surface endows the 3D self-standing cathode with accessible active sites, favorable mass transfer, electrical conductivity, and structural stability to achieve ampere-level current density hydrogen evolution reaction at low overpotentials.image