The conventional fabrication of bulk van der Waals (vdW) materials requires a temperature above 1,000 °C to sinter from the corresponding particulates. Here we report the near-room-temperature densification (for example, ∼45 °C for 10 min) of two-dimensional nanosheets to form strong bulk materials with a porosity of <0.1%, which are mechanically stronger than the conventionally made ones. The mechanistic study shows that the water-mediated activation of van der Waals interactions accounts for the strong and dense bulk materials. Initially, water adsorbed on two-dimensional nanosheets lubricates and promotes alignment. The subsequent extrusion closes the gaps between the aligned nanosheets and densifies them into strong bulk materials. Water extrusion also generates stresses that increase with moulding temperature, and too high a temperature causes intersheet misalignment; therefore, a near-room-temperature moulding process is favoured. This technique provides an energy-efficient alternative to design a wide range of dense bulk van der Waals materials with tailored compositions and properties.

块状范德华 (vdW) 材料的传统制造需要 1,000 °C 以上的温度才能从相应的颗粒中烧结出来。在这里，我们报告了二维纳米片的近室温致密化（例如，~ 45°C 10 分钟），形成孔隙率 <0.1% 的坚固块体材料，其机械强度比传统制造的材料更强。机理研究表明，水介导的范德华相互作用激活导致了坚固而致密的散装材料。最初，吸附在二维纳米片上的水起到润滑作用并促进排列。随后的挤压会闭合对齐的纳米片之间的间隙，并将其致密化为坚固的块状材料。水挤出还会产生应力，该应力随成型温度而增加，温度过高会导致片材间错位；因此，接近室温的成型工艺受到青睐。该技术提供了一种节能的替代方案，可以设计各种具有定制成分和性能的致密散装范德华材料。