Disorder engineering in transition metal dichalcogenides toward efficient high current density reduction electrocatalysts

Abstract In this perspective, we highlight the importance of nanoscale disorder and mesoscale morphology to enhance the activity and tune the selectivity of group VI transition metal dichalcogenide electrocatalysts toward two paramount reductions reactions as H2 evolution reaction and CO2 reduction. The strategy we propose takes advantage of the metastable nanoscale atomic arrangement of highly disordered and amorphous materials, to overcome the limits of the typical transition metal dichalcogenide crystalline catalysts. For the H2 evolution reaction, going beyond the creation of point defects in crystalline structures in favor of fully amorphous organizations not only increases the per-site activity and active surface area but also improves the conductivity and the reaction kinetics. In addition, the incorporation of nanoscale disorder promotes the formation of complex products in CO2 reduction through reaction pathways inaccessible on other sites. On the other hand, the mesoscale architecture of the catalyst controls mass transport in both the liquid and gas phase, as well as determines the real-world performance of catalysts. We suggest that by exploiting disordered nanoscale organization and controlled mesoscale features, the performances can be drastically improved to reach the state-of-art metallic electrocatalysts.