The impact of the crystalline phase and morphology of MoS2 on the electrocatalytic reduction of H2O2

Abstract Efficient hydrogen peroxide (H2O2) detection is crucial for electrochemical and colorimetric sensors, making the hydrogen peroxide reduction reaction (HPRR) a key area of catalysis. In this context, molybdenum disulfide (MoS2) has emerged as a valuable HPRR catalyst. Here, we report the first experimental investigation comparing the electrocatalytic properties of MoS2 enriched with different phases (2H and 1T) and showcasing diverse morphologies toward HPRR. We provide unprecedented parameters (Tafel slope, constant, and exchange current density) describing the materials’ HPRR performance through state-of-the-art electrochemical techniques, including Tafel plots and EIS. Our findings reveal that 1T-enriched MoS2 outcompetes 2H-MoS2. Moreover, we show that the distinct morphologies of 1T-MoS2, such as exfoliated nanosheets and hydrothermally synthesized nanoflowers, strongly influence the kinetics of the catalytic reaction. This study bridges the gap between MoS2 structural properties and its electrocatalytic activity for HPRR, facilitating the selection of optimal MoS2 materials for high-sensitivity hydrogen peroxide sensors.