A first-principles investigation on the potential energy surfcae for Transition Metals adsorbed on Biphenylene

Biphenylene, a recently synthesized graphene allotrope composed of 4-, 6-, and 8-membered carbon rings, exhibits metallic rather than semimetallic behavior. Although its applications remain to be fully explored, its relatively large pores suggest potential for hydrogen storage and CO₂ capture. Since carbon-based materials generally possess weak adsorption capacity, transition metals can serve as catalysts to enhance their properties. Here, we systematically investigated the adsorption behavior of transition metals on biphenylene. Certain metals exhibit strong binding, with adsorption energies ranging from –2 to –4.5 eV per atom. Interestingly, most metals display a pronounced energy valley along the centers of the four- and six-membered rings, particularly scandium, titanium, and vanadium. The potential barrier along this valley (0.5–0.7 eV) indicates facile diffusion, leading to the spontaneous formation of linear atomic chains. These results highlight biphenylene as an excellent template for the growth of one-dimensional transition-metal chains, thereby expanding its potential in the design of nanoscale materials.