Extending the Colloidal Transition Metal Dichalcogenide Library to ReS Nanosheets for Application in Gas Sensing and Electrocatalysis.

Among the large family of transition metal dichalcogenides, recently ReS has stood out due to its nearly layer-independent optoelectronic and physicochemical properties related to its 1T distorted octahedral structure. This structure leads to strong in-plane anisotropy, and the presence of active sites at its surface makes ReS interesting for gas sensing and catalysts applications. However, current fabrication methods use chemical or physical vapor deposition (CVD or PVD) processes that are costly, time-consuming and complex, therefore limiting its large-scale production and exploitation. To address this issue, a colloidal synthesis approach is developed, which allows the production of ReS at temperatures below 360 °C and with reaction times shorter than 2h. By combining the solution-based synthesis with surface functionalization strategies, the feasibility of colloidal ReS nanosheet films for sensing different gases is demonstrated with highly competitive performance in comparison with devices built with CVD-grown ReS and MoS . In addition, the integration of the ReS nanosheet films in assemblies together with carbon nanotubes allows to fabricate electrodes for electrocatalysis for H production in both acid and alkaline conditions. Results from proof-of-principle devices show an electrocatalytic overpotential competitive with devices based on ReS produced by CVD, and even with MoS , WS , and MoSe electrocatalysts.