High Phase‐Purity 1T‐MoS 2 Ultrathin Nanosheets by a Spatially Confined Template

The crystal phase plays an important role in controlling the properties of a nanomaterial; however, it is a great challenge to obtain a nanomaterial with high purity of the metastable phase. For instance, the large‐scale synthesis of the metallic phase MoS 2 (1T‐MoS 2 ) is important for enhancing electrocatalytic reaction, but it can only be obtained under harsh conditions. Herein, a spatially confined template method is proposed to synthesize high phase‐purity MoS 2 with a 1T content of 83 %. Moreover, both the confined space and the structure of template will affect the purity of 1T‐MoS 2 ; in this case, this approach was extended to other similar spatially confined templates to obtain the high‐purity material. The obtained ultrathin nanosheets exhibit good electrocatalytic activity and excellent stability in the hydrogen evolution reaction.