Templated Growth of In2S3 in Ti3C2TX MXene with Enhanced Photocatalytic Properties

The growth of ultrathin semiconductors is advantageous for photocatalysis due to improved photophysical properties and reduced charge recombination. Along these lines, templating the growth of semiconductors in confined spaces can allow control over semiconductor growth while also conferring the properties of the template to provide composite nanomaterial hybrids. Herein, the semiconductor In2S3 is grown in the organically-modified interlayer space of Ti3C2TX MXene, a versatile 2D material with metallic character and broadband light absorption. The growth of 1-2 nm thick layers of In2S3 in the interlayer of MXene leads to a drastic increase in photocatalytic properties and light-induced charge generation due to decreased interfacial charge transfer resistance. Interestingly, the hydrothermal conditions of In2S3 growth lead to partial oxidation of Ti3C2TX MXene to form anatase TiO2 nanocrystals, although this effect is strongly limited by increased In2S3 precursors due to passivation of the MXene surface. MXenes serve as effective templates for the confined growth of semiconductors, emphasizing the potential of MXene as a template for 2D material heterostructures. Overall, this work further develops MXene-based 2D material composites, offering insights into the origins of the enhanced photocatalytic and photoelectrochemical properties, toward improvements in energy production and aqueous phase catalysis.