Insulating electronic states near the Dirac point arising from twisted stacking and curvature in 3D nanoporous graphene

Yoichi Tanabe ,  Hayato Sueyoshi ,  Samuel Jeong ,  Kojiro Imai ,  Shojiro Kimura ,  Yoshikazu Ito

Twist-stacked graphene with a twist angle  of  retains two-dimensional monolayer graphene–like Dirac states near the Dirac point. In three-dimensional nanoporous graphene (3D-NPG), curvature inherently produces twist-stacking and topological defects required to form a porous network. When regions with θ ≥ 5° dominate, Dirac states in individual layers are expected to persist, allowing the Dirac-electron behavior to be tuned through coupling to the 3D curved geometry. However, predicted band gap formation or localized states have remained unobserved. Here we report that 3D-NPG maintains monolayer-like Dirac electronic states while simultaneously exhibiting insulating behavior near the Dirac point. Raman G-band softening confirms these monolayer-like states, and an Arrhenius-type temperature–resistance trend coexisting with weak localization near the Dirac point indicates partially insulating states induced by topological defects. These findings demonstrate that 3D-NPG hosts distinctive Dirac electronic states coupled to 3D curvature, providing a platform for developing new functionalities in 3D graphene-based electronics and energy devices.

Carbon

Elsevier

255

121421

https://doi.org/10.1016/j.carbon.2026.121421