MoS2 quantum dot-modified MXene nanoflowers for efficient electrocatalytic hydrogen evolution reaction

Abstract

Electrochemical water splitting clutches abundant capacity as it produces molecular hydrogen as an efficient energy carrier. An effective hydrogen evolution reaction (HER) catalyst with decreased overpotentials and long-term stability is a necessity for electrochemical water splitting to fulfil the needs of the hydrogen economy. Slack anchoring of an active electrocatalyst on the substrate can significantly lead to a decline in its performance in any system. This study focuses on the synthesis of molybdenum sulphide (MoS₂) quantum dot-modified MXene nanoflowers (MQD@NFs) by hydrothermal treatment. Further analysis shows that MQDs have been successfully embedded inside the nanoflowers, which facilitate electron transfer and provide a stable structure. MQD@NFs exhibited excellent catalytic activity towards HER in an acidic environment and achieved HER performance at a current density of 10 mA cm⁻², with an overpotential of 307 mV and a Tafel slope of 68.5 mV dec⁻¹ in 0.5 M H₂SO₄. Additional catalytic sites on synthesized MQD@NFs enhance ceaseless efforts toward the facile synthesis of economically viable electrocatalysts for hydrogen generation. A graphite rod of 3 mm diameter was employed as the counter electrode with the synthesized working electrode and reference electrode to evaluate the HER performance.