Polymer-Embedded Fabrication of Co₂P Nanoparticles Encapsulated in N,P-Doped Graphene for Hydrogen Generation

Abstract

We developed a method to engineer well-distributed dicobalt phosphide (Co2P) nanoparticles encapsulated in N,P-doped graphene (Co2P@NPG) as electrocatalysts for hydrogen evolution reaction (HER). We fabricated such nanostructure by the absorption of initiator and functional monomers, including acrylamide and phytic acid on graphene oxides, followed by UV-initiated polymerization, then by adsorption of cobalt ions and finally calcination to form N,P-doped graphene structures. Our experimental results show significantly enhanced performance for such engineered nanostructures due to the synergistic effect from nanoparticles encapsulation and nitrogen and phosphorus doping on graphene structures. The obtained Co2P@NPG modified cathode exhibits small overpotentials of only -45 mV at 1 mA cm(-2), respectively, with a low Tafel slope of 58 mV dec(-1) and high exchange current density of 0.21 mA cm(-2) in 0.5 M H2SO4. In addition, encapsulation by N,P-doped graphene effectively prevent nanoparticle from corrosion, exhibiting nearly unfading catalytic performance after 30 h testing. This versatile method also opens a door for unprecedented design and fabrication of novel low-cost metal phosphide electrocatalysts encapsulated by graphene.

Large-Scale Synthesis of Carbon-Shell-Coated FeP Nanoparticles for Robust Hydrogen Evolution Reaction Electrocatalyst

“…Regarding the durability problem, a number of recent studies showed that carbonencapsulation of nanoparticles (NPs) can considerably improve their long-term stability in harsh reaction conditions for electrochemical reactions. [24][25][26][27][28][29][30] For example, the Bao group reported that CoNi alloy NPs coated with graphene show good long-term durability (up to 1000 cycles). 31 Our IBS Center previously reported that encapsulation of FePt alloy NPs with carbon shell resulted in exceptional thermal stability at annealing temperature as high as 700 o C. 32 Being inspired by those examples, we conjectured that carbon shell formation can be a general strategy of providing physicochemical protection for various nanocatalysts, including metal phosphides, to achieve high stability.…”

A Co2P/WC Nano‐Heterojunction Covered with N‐Doped Carbon as Highly Efficient Electrocatalyst for Hydrogen Evolution Reaction

“…[1,2] Water electrolysis is at heoretically attractivem ethod for the hydrogen evolution reaction( HER). [36] Significant effort has been made for the construction of Co 2 Pn anostructures and the regulation of its morphology and size for improving the HER performance. [3][4][5] Pt-basedc atalysts perform well in the HER; however, because of the high cost and lowa bundance of Pt metal on earth, variousn onprecious-metal-based electrocatalysts have been designed to tackle these problems.…”

Facile synthesis and excellent electrochemical performance of CoP nanowire on carbon cloth as bifunctional electrode for hydrogen evolution reaction and supercapacitor

“…60 No. 12 performed by E RHE =0.281+E SCE . Linear sweep voltammetry (LSV) was performed at a scan rate of 5 mV s −1 .…”

“…Clean energy sources have attracted extensive attention from many researchers in the past few years, such as nuclear power [5,6], solar energy [7], wind energy [8], tidal power [9] and hydrogen [10,11]. Hydrogen, as a clean and sustainable energy carrier, is considered one of the most ideal candidates to replace fossil fuels in the future [3,12]. Efficient hydrogen production is critical for developing hydrogen energy technology.…”

“…Transition metal phosphides, particularly cobalt phosphide and its derivatives, have been broadly studied as anode materials for Li-ion batteries, and electrocatalysts for HER, oxygen evolution reaction, and hydrodesulfurization and hydrodenitrogenation reactions. Recent reports have indicated that transition metal phosphides (cobalt, nickel, iron phosphides) display good performance for HER owing to their good electrical conductivity [12,20,21]. Electrical conductivity is also a critical parameter for supercapacitor anode materials.…”