Molybdenum Phosphide Quantum Dots Encapsulated by P/N‐Doped Carbon for Hydrogen Evolution Reaction in Acid and Alkaline Electrolytes

Abstract

A facile and eco‐friendly strategy is presented for synthesizing novel nanocomposites, with MoP quantum dots (QDs) as cores and graphitic carbon as shells, these nanoparticles are dispersed in a nitrogen and phosphorus‐doped porous carbon and carbon nanotubes (CNTs) substrates (MoP@NPC/CNT). The synthesis involves self‐assembling reactions to form single‐source precursors (SSPs), followed by pyrolysis at 900 °C in an inert atmosphere to obtain MoP@NPC/CNT‐900. The presence of carbon layers on the MoP QDs effectively prevents particle aggregation, enhancing the utilization of active MoP species. The optimized sample, MoP@NPC/CNT‐900, exhibits remarkable electrocatalytic activity and durability for the hydrogen evolution reaction (HER). It demonstrates a low overpotential of 155 mV at 10 mA cm−2, a small Tafel slope of 76 mV dec−1, and sustained performance over 20 hours in 0.5 M H2SO4. Furthermore, the catalyst shows excellent activity in 1 M KOH, with a relatively low overpotential of 131 mV and long‐term durability under constant current input. The exceptional HER activity can be attributed to several factors: the superior performance of MoP QDs, the large surface area and good conductivity of the carbon substrates, and the synergistic effect between MoP and carbon species.

Ni/TiO2 heterostructures derived from phase separation for enhanced electrocatalysis of hydrogen evolution and biomass oxidative upgrading in anion exchange membrane electrolyzers

“…22 It should be noted that most studies in this area are focused on noble metal-based catalysts, and there is an obvious difference between noble metal-based and noble metal-free catalysts in the kinetic pH effect on HERs. 26–28 Therefore, it is necessary to investigate the properties of the electric double layer of noble metal-free catalysts ( e.g. , Ni/TiO 2 ) to gain a deep insight into the reaction mechanism of HERs.…”

High-Performance MoP-Mo2C/C Heterogeneous Nanoparticle Catalysts for Alkaline Hydrogen Evolution and Oxidation Reactions

“…Transition metal phosphides (TMPs) are characterized by low cost, good catalytic stability, and a unique catalytic mechanism similar to that of hydrogenases. , Among TMPs, MoP has been extensively studied in electrocatalysis due to its high activity and feasibility . Chen et al prepared MoP@NPC/CNT that required an overpotential of 155 mV to achieve 10 mA cm –2 and exhibited excellent stability . However, current research suggests that excessive phosphorus content in an alkaline environment can lead to electrochemical polarization and decreased conductivity, thereby slowing down the kinetics of both HER and HOR processes. , Moreover, the available MoP catalyst preparation methods are complicated and inefficient.…”

“…10 Chen et al prepared MoP@ NPC/CNT that required an overpotential of 155 mV to achieve 10 mA cm −2 and exhibited excellent stability. 11 However, current research suggests that excessive phosphorus content in an alkaline environment can lead to electrochemical polarization and decreased conductivity, thereby slowing down the kinetics of both HER and HOR processes. 12,13 Moreover, the available MoP catalyst preparation methods are complicated and inefficient.…”