Hydrogen Splitting Using Single Metal Atom Doped C3N Nanosheet as a Catalyst: A DFT Study

Abstract

Atomic hydrogen is the most intriguing free radical for high-energy applications. The ability of atomic hydrogen to protect DNA and mitochondria from oxidative damage may be advantageous in the treatment of chronic illnesses including cancer. When dissociation energy is supplied, a molecule of hydrogen dissociates into two atoms (H2 → 2H). In contrast to other radicals, hydrogen recombination requires no activation energy. The highest efficiency and stability for heterogeneous catalysis of hydrogen splitting are provided by single-atom catalysts adsorbed on the active surface. For support of single-atom catalyst (SAC), carbon nanotubes, graphene, metal hydrides, metal-organic frameworks, graphene, graphdiyne, carbon nitride, and silanes surfaces have been employed recently. The presence of nitrogen in carbon nitride surfaces is shown to be much more effective for hydrogen dissociation and considered as the most suitable substrate for SAC. Because of their varying oxidation states, transition metals have several spin states that can be tested, and the most stable spin states based on thermodynamic energy data may be determined. The optimized C3N nanosheet is doped with 3d transition metals. The lowest energy spin state of each doped metal is considered for further calculations. The stabilities of complexes have been measured by calculating the interaction energies of optimized geometries. Adsorption energies of H2 on metal doped carbon nitride surface are computed to investigate the adsorption mechanism and characterize the energetic heterogeneity of solid surfaces. The energy barrier (activation energy) and reaction energies are required to determine the splitting of hydrogen. This study shows that SAC can be used as the most efficient doping technique for hydrogen splitting.