Colloidal Ni2-: XCoxP nanocrystals for the hydrogen evolution reaction

A cost-effective and scalable approach was developed to produce monodisperse Ni2-xCoxP nanocrystals (NCs) with composition tuned over the entire range (0 = x = 2). Ni2-xCoxP NCs were synthesized using low-cost, stable and low-toxicity triphenyl phosphite (TPP) as a phosphorus source, metal chlorides...

Descripción completa

Detalles Bibliográficos
Autores: Liu, Junfeng, Wang, Zhenxing, David, Jeremy, Llorca Piqué, Jordi|||0000-0002-7447-9582
Tipo de recurso: artículo
Fecha de publicación:2018
País:España
Institución:Universitat Politècnica de Catalunya (UPC)
Repositorio:UPCommons. Portal del coneixement obert de la UPC
Idioma:inglés
OAI Identifier:oai:upcommons.upc.edu:2117/119655
Acceso en línea:https://hdl.handle.net/2117/119655
https://dx.doi.org/10.1039/c8ta03485k
Access Level:acceso abierto
Palabra clave:Nanocrystals
Hydrogen
Nanocristalls
Hidrogen
Àrees temàtiques de la UPC::Enginyeria química
Descripción
Sumario:A cost-effective and scalable approach was developed to produce monodisperse Ni2-xCoxP nanocrystals (NCs) with composition tuned over the entire range (0 = x = 2). Ni2-xCoxP NCs were synthesized using low-cost, stable and low-toxicity triphenyl phosphite (TPP) as a phosphorus source, metal chlorides as metal precursors and hexadecylamine (HDA) as a ligand. The synthesis involved the nucleation of amorphous Ni–P and its posterior crystallization and simultaneous incorporation of Co. The composition, size and morphology of the Ni2-xCoxP NCs could be controlled simply by varying the ratio of Ni and Co precursors and the amounts of TPP and HDA. Ternary Ni2-xCoxP-based electrocatalysts exhibited enhanced electrocatalytic activity toward the hydrogen evolution reaction (HER) compared to binary phosphides. In particular, NiCoP electrocatalysts displayed the lowest overpotential of 97 mV at J = 10 mA cm-2 and an excellent long-term stability. DFT calculations of the Gibbs free energy for hydrogen adsorption at the surface of Ni2-xCoxP NCs showed NiCoP to have the most appropriate composition to optimize this parameter within the whole Ni2-xCoxP series. However, the hydrogen adsorption energy was demonstrated not to be the only parameter controlling the HER activity in Ni2-xCoxP.