Jiao Yanqing, Yan Haijing, Wang Ruihong, Wang Xiuwen, Zhang Xiaomeng, Wu Aiping, Tian Chungui, Jiang Baojiang, Fu Honggang
Key Laboratory of Functional Inorganic Material Chemistry, Ministry of Education of China, Heilongjiang University, Harbin 150080, China.
ACS Appl Mater Interfaces. 2020 Nov 4;12(44):49596-49606. doi: 10.1021/acsami.0c13533. Epub 2020 Oct 22.
Molybdenum phosphide is one of the most potential electrocatalysts for the hydrogen evolution reaction (HER), whereas it is still challenging to achieve an efficient molybdenum phosphide-based catalyst that performs well over a wide pH range. Herein, a porous nanoplate composed of small MoP flakes confined in thin N, P, S-triple-doped carbon (MoP@NPSC) was prepared by the assembly of phosphomolybdic acid (HPMoO·HO, {PMo}) and egg white, followed by phosphorization. Given its small size (ca. 1 nm) in favor of deriving small particles and the oxygen-rich surface with strong coordination ability, the {PMo} cluster was selected to combine with egg white to obtain a lamellar hybrid precursor via a hydrogen bond. Through controllable phosphating, a nanoplate organized by interconnected MoP particles was generated, accompanied by the in situ formation of the N, P, S-doped carbon thin layer and pores from the pyrolysis of egg white. The plentiful pores, thin carbon coating, and multielement doping bring about promoted electrolyte/bubble diffusion, enhanced conductivity and stability, and lowered adsorption energy of hydrogen/hydroxyl, respectively. All of the above merits endow MoP@NPSC with prominent activity with low overpotentials of 50, 76, and 71 mV at 10 mA cm toward the HER in alkaline, neutral, and acid media, respectively, and nearly no attenuation after 40 h of testing. Especially, compared with commercial Pt/C, MoP@NPSC exhibits similar low onset potential and even better at large current density in 1 M KOH. The electrolyzer equipped with the MoP@NPSC cathode and the NiFe-LDH anode requires only 1.52 V to deliver 10 mA cm and can be powered by a solar cell (1.524 V) charged by sunlight.
磷化钼是析氢反应（HER）最具潜力的电催化剂之一，然而，制备一种在宽pH范围内都表现良好的高效磷化钼基催化剂仍然具有挑战性。在此，通过磷钼酸（HPMoO·HO，{PMo}）与蛋清组装，随后进行磷化处理，制备了一种由小尺寸MoP薄片限制在薄的N、P、S三掺杂碳（MoP@NPSC）中的多孔纳米片。鉴于其有利于衍生小颗粒的小尺寸（约1nm）和具有强配位能力的富氧表面，选择{PMo}簇与蛋清结合，通过氢键获得层状杂化前驱体。通过可控磷化，生成了由相互连接的MoP颗粒组成的纳米片，同时伴随着蛋清热解原位形成N、P、S掺杂碳薄层和孔隙。丰富的孔隙、薄碳涂层和多元素掺杂分别促进了电解质/气泡扩散、提高了导电性和稳定性，并降低了氢/羟基的吸附能。上述所有优点赋予MoP@NPSC显著的活性，在碱性、中性和酸性介质中，在10 mA cm下析氢过电位分别为50、76和71 mV，测试40 h后几乎没有衰减。特别是，与商业Pt/C相比，MoP@NPSC在1 M KOH中表现出相似的低起始电位，在大电流密度下甚至更好。配备MoP@NPSC阴极和NiFe-LDH阳极的电解槽仅需1.52 V就能提供10 mA cm，并且可以由阳光充电的太阳能电池（1.524 V）供电。
