Nanohybrid of Carbon Quantum Dots/Molybdenum Phosphide Nanoparticle for Efficient Electrochemical Hydrogen Evolution in Alkaline Medium

The exploration of highly efficient non-noble metal electrocatalysts for hydrogen evolution reaction (HER) under alkaline conditions is highly imperative but still remains a great challenge. In this work, the nanohybrid of carbon quantum dots and molybdenum phosphide nanopartide (CQDs/MoP) has been firstly demonstrated as an efficient alkaline HER electrocatalyst. The CQDs/MoP nanohybrid is readily prepared through a charge-directed self-assembly of CQDs with phosphomolybdic acid (H3PMo12O40) at the molecular level, followed by facile phosphatizing at 700 degrees C. The introduction of CQDs greatly helps to alleviate the agglomeration and surface oxidation of MoP nanoparticles and ensures each MoP nanoparticle to be electronically addressed, thus significantly enhancing the intrinsic catalytic activity of MoP. The optimized CQDs/MoP exhibits high-efficiency synergistic catalysis toward HER in 1 M KOH electrolyte with a low onset potential of -0.08 V and a small Tafel slope of 56 mV dec(-1) as well as high durability with negligible current loss for at least 24 h.

在碱性条件下探索高效的非贵金属析氢反应（HER）电催化剂是非常必要的，但仍然是一个巨大的挑战。在这项工作中，碳量子点和磷化钼纳米粒子的纳米杂化物（CQDs/MoP）首次被证明是一种高效的碱性HER电催化剂。CQDs/MoP纳米杂化物通过碳量子点与磷钼酸（H₃PMo₁₂O₄₀）在分子水平上的电荷导向自组装，然后在700℃下进行简便的磷化处理而容易制备。碳量子点的引入极大地有助于缓解MoP纳米粒子的团聚和表面氧化，并确保每个MoP纳米粒子都能被电子调控，从而显著提高MoP的本征催化活性。优化后的CQDs/MoP在1 M KOH电解液中对HER表现出高效的协同催化作用，具有-0.08 V的低起始电位和56 mV dec⁻¹的小塔菲尔斜率，以及至少24小时内电流损失可忽略不计的高耐久性。