W-doping induced abundant active sites in a 3D NiS2/MoO2 heterostructure as an efficient electrocatalyst for urea oxidation and hydrogen evolution reaction

Urea electrooxidation has received considerable attention because of its tremendous practical application in environmental protection and energy regeneration. As an electrochemical reaction, the catalytic performance of urea oxidation is highly...

A review of hetero-structured Ni-based active catalysts for urea electrolysis

Ni modified Co2VO4 heterojunction with poor/rich-electron structure for overall urea-rich wastewater oxidation

Electronic structure optimization and architecture modulation are widely regarded as rational strategies to enhance the electrocatalysts catalytic performance. Herein, a hybridization of ZIF-67-derived CoP nanoparticles embedded in P, N co-doped carbon matrix (PNC) and anchored on P-doped carbonized wood fibers (PCWF) is constructed using a simple simultaneous phosphorization and carbonization strategy. Benefiting from the optimized surface/interface electronic structures, abundant exposed active sites, and outstanding conductivity, the CoP@PNC/PCWF can drive the urea oxidation reaction (UOR) with greater activity and better stability than most recently reported electrocatalysts, in which a potential as low as 1.32 V (vs reversible hydrogen electrode, RHE) is needed to reach 50 mA cm-2 and shows excellent durability. Furthermore, for overall urea splitting, using the CoP@PNC/PCWF electrocatalyst as the anode and commercial Pt/C supported on nickel foam as the cathode, an ultralow cell voltage of 1.50 V (vs RHE) is expected to achieve the 50 mA cm-2 and operate continuously for more than 50 h at 20 mA cm-2 . The reported strategy may shed light on the use of renewable resources to design and synthesize high-performance non-Ni-based phosphides UOR electrocatalysts for energy-saving H2 production.

CoP Nanoparticle Confined in P, N Co-Doped Porous Carbon Anchored on P-Doped Carbonized Wood Fibers with Tailored Electronic Structure for Efficient Urea Electro-Oxidation.

In this study, heterogeneous nickel phosphide‐nickel selenide (Ni2P‐NiSe2) nanosheets are constructed to coat zinc phosphide‐based nanorods (ZnP NRs) under a unique core@shell architecture, which acts as a highly active multifunctional catalyst toward hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). The catalyst exhibits an overpotential of 79 mV at 10 mA cm–2 for HER and 326 mV at 100 mA cm–2 for OER in freshwater under an alkaline condition. The formation of an open 3D channel architecture derived from highly conductive ZnP@Ni2P‐NiSe2 nanorods attached nickel foam generates more exposed active sites and promotes fast mass transport. In addition, density functional theory study reveals a synergistic effect between Ni2P and NiSe2 phase to reduce adsorption free energy and increase the electronic conductivity, thereby accelerating the catalytic reaction kinetics. An electrolyzer of the ZnP@Ni2P‐NiSe2(+,‐) requires only cell voltages of 1.54 V (1.43 V) and 1.51 V (1.44 V) to deliver 10 mA cm–2 in freshwater and mimic seawater at 25 °C (75 °C), respectively, along with prospective long‐term stability. Furthermore, the solar energy‐assisted water splitting process demonstrates a solar‐to‐hydrogen efficiency of 19.75%, implying that the catalyst is an effective and low‐cost candidate for water splitting.

Atomic Heterointerface Engineering of Ni2P‐NiSe2 Nanosheets Coupled ZnP‐Based Arrays for High‐Efficiency Solar‐Assisted Water Splitting

Engineering NiF3/Ni2P heterojunction as efficient electrocatalysts for urea oxidation and splitting

Phase and crystallinity regulations of Ni(OH)2 by vanadium doping boost electrocatalytic urea oxidation reaction.

F-decoration-induced partially amorphization of nickel iron layered double hydroxides for high efficiency urea oxidation reaction.

Coupling Dual-phased nickel selenides with N-doped carbon enables efficient urea electrocatalytic oxidation.

Hierarchical nickel–cobalt alloy pearl strings (NCPS) are successfully fabricated and exhibit superior electrocatalytic activity toward urea. The NCPS Ni4Co1 with an initial Ni/Co ratio of 4 : 1 delivers a current density of 51.5 mA cm−2 at 0.5 V vs. Ag/AgCl, which is much higher than that of its metallic Ni metal counterpart, and a relatively low onset potential.

Kaili Wang

Papers

Engineering NiF3/Ni2P heterojunction as efficient electrocatalysts for urea oxidation and splitting

Phase and crystallinity regulations of Ni(OH)2 by vanadium doping boost electrocatalytic urea oxidation reaction.

F-decoration-induced partially amorphization of nickel iron layered double hydroxides for high efficiency urea oxidation reaction.

Coupling Dual-phased nickel selenides with N-doped carbon enables efficient urea electrocatalytic oxidation.

Hierarchical NiCo pearl strings as efficient electrocatalysts for urea electrooxidation