Heterointerface Engineering of Ni₂P–Co₂P Nanoframes for Efficient Water Splitting

Abstract

Designing highly active, stable, bifunctional, noble-metal-free electrocatalysts for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) is a major challenge in water splitting. We report here a novel, frame-like nanostructured catalyst (Ni,Co)2P nanoframe (NF), which consists of heterostructured Ni2P–Co2P nanoparticles embedded in the N-doped carbon matrix. Its synthesis involves precipitation, chemical etching, and a final phosphidation step to give an optimized electronic structure that contains multiple catalytic active sites and facilitates mass transfer. The catalyst is a bifunctional catalyst for both HER and OER and is superior to the individual components Ni2P and Co2P samples and (Ni,Co)2P solid nanocubes. When the (Ni,Co)2P NF catalyst was employed as both the cathode and anode for overall water splitting, a remarkably low cell voltage of 1.54 V was required to achieve a current density of 10 mA cm–2. Density functional theory calculations verify the strong electronic interaction between Ni2P and Co2P at the heterointerfaces, resulting in an optimized hydrogen adsorption strength for enhanced HER electrocatalysis. Moreover, the synthetic strategy has been generalized for the synthesis of Ni–Co dichalcogenide NFs, thereby holding a great promise for a variety of potential applications.

Boosting Synergy of Polymetal Phosphides by Core‐Shell Design of Prussian Blue Analogue Precursors as Electrocatalysts for Water Splitting

“…Previous density functional theory calculations reveal that synergy between CoP and Ni 2 P makes the CoP/Ni 2 P heterostructures more active than single phases by enhancing the adsorption of intermediate species in either OER [16] or HER [29] electrocatalysis. Based on the reported calculations and experimental results above, the catalytic activity of CoFe‐P shell in NiFe‐P@CoFe‐P‐x catalysts in this work can be enhanced by the interfaces of NiFe‐P and CoFe‐P that are mainly located at the inner surfaces of the cubic shell.…”

Hierarchical Metal Sulfides Heterostructure as Superior Bifunctional Electrode for Overall Water Splitting

“…In this regard, more efforts have been devoted to promote the catalytic performance of transition metal sulfides by designing more interfacial heterostructures or introducing more heterogeneous metal catalytic centers. [20][21][22][23][24] Abundant heterointerfaces and multi-metallic catalytic centers can provide more catalytic active sites and tune electronic structure and surface properties, resulting in significantly improved electrocatalytic performance. [25][26][27] For example, a hierarchical nanoassembly of interacting MoS 2 and Co 9 S 8 nanosheets is successfully grafted onto the surface of Ni 3 S 2 nanorod arrays.…”

“…However, the catalytic activity of single‐component sulfide is extremely limited due to the lack of more tunable parameters. In this regard, more efforts have been devoted to promote the catalytic performance of transition metal sulfides by designing more interfacial heterostructures or introducing more heterogeneous metal catalytic centers [20–24] . Abundant heterointerfaces and multi‐metallic catalytic centers can provide more catalytic active sites and tune electronic structure and surface properties, resulting in significantly improved electrocatalytic performance [25–27] .…”

NiCoP/Mo3Se4 Nano‐Heterojunction as a Promising Bifunctional Catalyst for Full‐Water Splitting under Low Cell Voltage

“…Electrochemical hydrolysis, as an effective method for producing high-quality hydrogen without carbon pollution, has received wide attention in recent years. [1][2][3][4] However, the sluggishness of water's decomposition kinetics remains a huge challenge, which has spurred interest in researchers to develop two highly efficient, low-dynamic overpotential catalysts to robustly decompose water. Although precious metals and precious metal oxides such as platinum, RuO 2 and IrO 2 are the most effective catalysts for hydrogen evolution (HER) or oxygen evolution (OER), scarcity has seriously hindered their practical application.…”

“…Electrochemical hydrolysis, as an effective method for producing high‐quality hydrogen without carbon pollution, has received wide attention in recent years [1–4] . However, the sluggishness of water‘s decomposition kinetics remains a huge challenge, which has spurred interest in researchers to develop two highly efficient, low‐dynamic overpotential catalysts to robustly decompose water.…”