Materials with an isotropic negative coefficient of thermal expansion (CTE) of the order of $-10^{-3}$ K⁻¹ are rare, and almost all of them are porous. Using molecular dynamics simulations, we show that graphene origami structures obtained by pattern-based hydrogenation can exhibit a negative CTE. The magnitude and anisotropy of the CTE can be controlled by parameters of the pattern-based hydrogenation that determine the stiffness and Poisson ratio, respectively. We achieve an isotropic CTE of $-20.7\times 10^{-3}$ K⁻¹, which is an enhancement by three orders of magnitude as compared to reports for other graphene-based structures and comes close to the record of all known materials.

具有各向同性负热膨胀系数 (CTE) 的材料 $-10^{-3}$K ^-1很少见，而且几乎都是多孔的。使用分子动力学模拟，我们表明通过基于图案的氢化获得的石墨烯折纸结构可以表现出负的 CTE。CTE 的大小和各向异性可以通过基于图案的氢化参数来控制，这些参数分别决定了刚度和泊松比。我们实现了各向同性的 CTE$-20.7\times 10^{-3}$K ^-1，与其他基于石墨烯的结构的报告相比提高了三个数量级，接近所有已知材料的记录。