Insight into the Superior Activity of Bridging Sulfur-Rich Amorphous Molybdenum Sulfide for Electrochemical Hydrogen Evolution Reaction

To realize more efficient electrocatalysts, newer architectures in molybdenum sulfide are required to allow more active S sites beyond the endemic structural limits. Pre-reaction between precursor and additional S source maximizes the active bridging S22− in amorphous molybdenum sulfide, leading to the highest proportion of bridging S22− (up to 67%), excellent HER activity (onset potential of −96 mV), and stability.