3D‐Printing of Freestanding Pure MXene Microarchitectures

Abstract Since their discovery, titanium‐based MXenes (Ti 3 C 2 T x ) have attracted significant attention. Several studies have presented versatile, cost‐effective, and scalable approaches for fabricating Ti 3 C 2 T x ‐based functional components. However, most previous studies only allowed the realization of 2D patterns or required diverse additives to produce 3D architectures. Herein, a 3D‐Printing approach for producing 3D microarchitectures composed entirely of Ti 3 C 2 T x . Ti 3 C 2 T x additive‐free aqueous ink consists of 0.1 wt.% Ti 3 C 2 T x nanosheets is proposed. The diameter ( d s ) of the printed Ti 3 C 2 T x 3D microarchitectures can be determined by controlling the meniscus channel size, which is influenced by the diameter ( d p ) of the micropipette opening and pipette‐pulling rate ( v ). Through optimized control of the pipette, a minimum d s of 1.3 µm is obtained, and complex shapes such as zigzag, helix, bridge, and pyramid shapes can be implemented. To demonstrate the feasibility of realizing functional Ti 3 C 2 T x 3D components, three electrical components are demonstrated: 3D micro‐interconnects and 3D transducers for photodetectors and humidity sensors. It is believed that this facile approach can be used for nano 3D‐Printing as well as micro printing of Ti 3 C 2 T x architectures.