Influence of uniform deposition of molybdenum disulfide particles on electrochemical reaction

Achieving a uniform coating of catalyst particles over an electrode surface is pivotal to enhancing the performance and efficiency of an electrochemical reaction. With this in mind, we investigated the degree of uniformity of molybdenum disulfide (MoS2) particle distribution on an electrode surface using spectroscopic techniques. Three different coating methods were used to coat the electrode surface: drop-casting, brushing, and spraying. The most uniform deposition of catalyst particles was achieved using the spray coating method, as it provided consistent distribution of tiny particles (∼1.66 μm) over the entire electrode surface without agglomeration; in some instances, thin, individual particles were layered vertically on the carbon fiber as well. The uniform catalyst particle coating provided using the spray coating method increases the current density to more than three times that of a non-uniformly coated electrode at the same applied potential (1.307 V vs. RHE), while reducing the overpotential and charge-transfer resistance by 60% and 70%, respectively; both are attributed to an increase in the surface area of the active catalytic site.