Porous flower-like nickel nitride as highly efficient bifunctional electrocatalysts for less energy-intensive hydrogen evolution and urea oxidation

Precious-Group-Metal-Free Energy-Efficient Urea Electrolysis: Membrane Electrode Assembly Cell Using Ni3N Nanoparticles as Catalyst

“…Metallic nickel nitrides (Ni 3 N) have the ability to surmount this difficulty because of their high electrical conductivity (metallic), thermal stability with exceptional hardness (covalent), and corrosion resistance under operating conditions. 23 In addition, due to their good HER activity, nickel nitrides behave as bifunctional catalysts, capable of both hydrogen generation and urea decomposition. The most adopted synthesis strategies of nickel nitrides reported to date follow a two-step procedure involving the conversion of nickel hydroxides or oxides, which results in sheetlike morphology and low surface area.…”

“…Ni-, Co-, Mn-, and Fe-based transition-metal catalysts have been investigated for alkaline UOR, and Ni-based systems have emerged as the highest efficiency catalysts. Metallic nickel, nickel-based alloys, oxides, and hydroxides are being actively researched. − Although Ni oxide/hydroxide catalysts have received great attention, their practical application is limited by their intrinsic low conductivity and stability. Metallic nickel nitrides (Ni 3 N) have the ability to surmount this difficulty because of their high electrical conductivity (metallic), thermal stability with exceptional hardness (covalent), and corrosion resistance under operating conditions .…”

“…Metallic nickel, nickel-based alloys, oxides, and hydroxides are being actively researched. − Although Ni oxide/hydroxide catalysts have received great attention, their practical application is limited by their intrinsic low conductivity and stability. Metallic nickel nitrides (Ni 3 N) have the ability to surmount this difficulty because of their high electrical conductivity (metallic), thermal stability with exceptional hardness (covalent), and corrosion resistance under operating conditions . In addition, due to their good HER activity, nickel nitrides behave as bifunctional catalysts, capable of both hydrogen generation and urea decomposition.…”

Recent Development of Nickel-Based Electrocatalysts for Urea Electrolysis in Alkaline Solution

“…Wang et al [ 111 ] published a 3D composite of nickel nitride with reduced graphene oxide, Ni 3 N/rGO@NF, using various annealing temperatures; the electrode s-350 exhibited excellent UOR performance of 1.342 V and HER performance at overpotential of 124 mV at 10 mA cm 2 . Zhao et al [ 112 ] reported the porous nickel nitride electrocatalyst Ni 3 N-350/NF, which was used as anode and cathode materials for water-urea electrolysis and displayed excellent catalytic activity and long-term stability for the HER and UOR. The assembled two-electrode electrolyzer (Ni 3 N-350/NF//Ni 3 N-350/NF) required lower voltage (1.51 V) to drive 100 mA cm −2 in water-urea electrolysis than for water electrolysis.…”

Ni2P Nanoparticle-Inserted Porous Layered NiO Hetero-Structured Nanosheets as a Durable Catalyst for the Electro-Oxidation of Urea

“…The following supporting information can be downloaded at: , Figure S1: EDX and STEM analysis of Ni2P@NiO/NiF–40 catalyst; Figure S2: XRD of Ni2P@NiO catalyst prepared at 20, and 60 min phosphating time; Figure S3: XPS spectra for Ni 2p and O 1s of Ni(OH)2/NiF catalyst; Figure S4: LSVs of Ni2P@NiO/NF-40 catalyst electrode displaying OER and EOU profiles; Figure S5: Mass activity based EOU responses at Ni2P NPs/NiF, NiO/NiF, and Ni2P@NiO/NiF; Figure S6: CVs obtained at different scan rates (20 mV/s to 100 mV/s) of Ni2P@NiO/NF-40, NiO/NF, Ni2P/NF and NiF toward EOU; Table S1: Comparison of UOR performance of some representative reported Ni-based catalysts. References [ 33 , 63 , 64 , 65 , 66 , 67 , 68 , 69 ] were cited in the Supplementary Materials.…”