Cobalt phosphide nanoparticles supported within network of N-doped carbon nanotubes as a multifunctional and scalable electrocatalyst for water splitting

In order to realize industrial production of hydrogen through water splitting,it is essential to develop a cost-efficient and scalable approach to synthesize nonprecious electrocatalysts with sufficiently high activity and stability to replace commercial noble-metal-based electrocatalysts.Herein we synthesize cobalt phosphide nanoparticles dispersed within nitrogen-doped carbon nanotube network(CP@NCNT) via scalable spray drying and thermal treatments.As a multifunctional electrocatalyst,the CP@NCNT hybrid delivers outstanding activity for HER(in both acidic and alkaline electrolytes),OER and overall water splitting.Remarkably,it shows an ultra-low overpotental of 94 mV to obtain 10 mA cm-2 in HER.It also demonstrates outstanding activity in overall water splitting,requiring only 1.619 V to deliver 10 mA cm-2with more than 72 h’ long-term stability.The combination of notable performance,multi-functionality and highly scalable spray-drying synthesis method enables this material as a novel and cost-efficient transition metal-based electrocatalysts for overall water splitting.

A co-coordination strategy to realize janus-type bimetallic phosphide as highly efficient and durable bifunctional catalyst for water splitting

In this work,a Janus-type dual-ligand metal-organic frameworks derived bimetallic(Fe,Co)P nanoparticles embedded carbon nanotube(CNT)skeleton(DLD-Fe Co P@CNT)is presented and synthesized via a facile"co-coordination synthesis"strategy.The DLD-Fe Co P@CNT hybrid shows much better performances for OER and HER with much lower Tafel slope of 39.6(57.1)m V dec-1,an overpotential of 286(166)m V@10 m A cm^(-2)and better stability for OER(HER)in 1 M KOH.Being both cathode and anode for water splitting,it requires only a low voltage of 1.67 V to obtain 10 mA cm^(-2)with nearly 100%faradaic efficiency,which is close to Pt/C//RuO_(2)cell.Density functional theory calculations based on the bimetallic phosphide(Fe_(0.3)Co_(0.7)P)model reveal that,compared with the monometallic Fe P or Co P,the enhanced catalytic activities of Fe_(0.3)Co_(0.7)P is mainly manifested in its free energy of H adsorption(GH*)closer to zero,larger binding strength for H2O and higher electrical conductivity.