Coleman Nathaniel, Liyanage Ishanka A, Lovander Matthew D, Leddy Johna, Gillan Edward G
Department of Chemistry, University of Iowa, Iowa City, IA 52242, USA.
Molecules. 2022 Aug 9;27(16):5053. doi: 10.3390/molecules27165053.
The facile solvent-free synthesis of several known metal thiophosphates was accomplished by a chemical exchange reaction between anhydrous metal chlorides and elemental phosphorus with sulfur, or combinations of phosphorus with molecular P2S5 at moderate 500 °C temperatures. The crystalline products obtained from this synthetic approach include MPS3 (M = Fe, Co, Ni) and Cu3PS4. The successful reactions benefit from thermochemically favorable PCl3 elimination. This solvent-free route performed at moderate temperatures leads to mixed anion products with complex heteroatomic anions, such as P2S64−. The MPS3 phases are thermally metastable relative to the thermodynamically preferred separate MPx/ MSy and more metal-rich MPxSy phases. The micrometer-sized M-P-S products exhibit room-temperature optical and magnetic properties consistent with isolated metal ion structural arrangements and semiconducting band gaps. The MPS3 materials were examined as electrocatalysts in hydrogen evolution reactions (HER) under acidic conditions. In terms of HER activity at lower applied potentials, the MPS3 materials show the trend of Co > Ni >> Fe. Extended time constant potential HER experiments show reasonable HER stability of ionic and semiconducting MPS3 (M = Co, Ni) structures under acidic reducing conditions.
通过无水金属氯化物与元素磷和硫，或磷与分子态P2S5在500℃适中温度下发生化学交换反应，轻松实现了几种已知金属硫代磷酸盐的无溶剂合成。通过这种合成方法得到的晶体产物包括MPS3（M = Fe、Co、Ni）和Cu3PS4。成功的反应得益于热化学上有利的PCl3消除。这种在适中温度下进行的无溶剂路线可得到具有复杂杂原子阴离子（如P2S64−）的混合阴离子产物。相对于热力学上更稳定的单独的MPx/MSy以及富含更多金属的MPxSy相，MPS3相是热亚稳的。微米级的M - P - S产物表现出与孤立金属离子结构排列和半导体带隙相一致的室温光学和磁性特性。在酸性条件下，对MPS3材料作为析氢反应（HER）的电催化剂进行了研究。就较低外加电势下的HER活性而言，MPS3材料呈现出Co > Ni >> Fe的趋势。延长时间常数电势的HER实验表明，在酸性还原条件下，离子型和半导体型的MPS3（M = Co、Ni）结构具有合理的HER稳定性。
