Novel Bifunctional V₂O₃ Nanosheets Coupled with N-Doped-Carbon Encapsulated Ni Heterostructure for Enhanced Electrocatalytic Oxidation of Urea-Rich Wastewater

Abstract

Developing high performance bifunctional transition metal catalysts would be significantly beneficial for electrocatalytic oxidation of urea-rich wastewater. Herein, we synthesize a V2O3 nanosheet anchored N-doped-carbon encapsulated Ni heterostructure (Ni@C–V2O3/NF) for the reactions of urea oxidation (UOR) and hydrogen evolution (HER). Electrochemical results indicate that it exhibits small potentials of 1.32, 1.39, and 1.43 V for UOR and low overpotentials of 36, 254, and 355 mV for HER at ±10, ± 500 and ±1000 mA cm–2, respectively. It can work at 100 mA cm–2 for over 72 h as cathode and anode electrode without obvious attenuation, suggesting an outstanding durability. The reason for this behavior could be ascribed to the N-doped-carbon coating structure, the synergetic effects between Ni and V2O3, and the nano/micro nanosheets architecture self-supported on nickel foam. This work could provide a promising, inexpensive, and green method for the degradation of urea-rich wastewater and hydrogen production.

Hierarchical Iron Phosphides Composite Confined in Ultrathin Carbon Layer as Effective Heterogeneous Electro‐Fenton Catalyst with Prominent Stability and Catalytic Activity

“…As the transition metals species immobilized on the surface of heterogeneous EF catalysts in solid form, both the catalytic formation and decomposition of H 2 O 2 mainly occur on the liquid-solid interfaces of catalysts. [8] Within this context, the heterogeneous EF catalysts require considerable activity for both H 2 O 2 generation and decomposition, [9][10][11] which consequently increase the difficulty in catalyst design and fabrication due to the higher structural complexity of the catalyst. Currently, carbon matrix (C) supported transition metal (TM) materials (TM/C) still majored in the preparation of heterogeneous EF catalyst , [12][13][14] where TM and carbon matrix could serves as the heterogeneous Fenton and 2e − oxygen reduction reaction (ORR) actives sites, [15] respectively.…”

Manipulation of Mott−Schottky Ni/CeO2 Heterojunctions into N‐Doped Carbon Nanofibers for High‐Efficiency Electrochemical Water Splitting

“…[23,24] Unfortunately, restricted by the poor intrinsic activity and insufficient stability under long-term stringent operation conditions, the overall electrocatalytic efficiency of Ni for overall water splitting is still inferior to the noble-metal-based benchmarks. To circumvent these dilemmas, substantial endeavors, encompassing multi-metal alloying, [25][26][27] hybridization with nanocarbons, [28,29] hetero-interfacial engineering, [30][31][32][33] etc., have been continuously devoted to optimizing the electrocatalytic performance of Ni from the perspectives of electronic regulation and nanoarchitectonics design. Among diverse strategies for electronic modification, the manipulation of heterojunctions between different functional components could effectively induce the electron reconfiguration of the adjacent moieties, promote the charge transfer efficiency, and alter the electron density of activity sites, thus causing some unusual physicochemical properties.…”

Heterostructured Ni3S2–Ni3P/NF as a Bifunctional Catalyst for Overall Urea–Water Electrolysis for Hydrogen Generation

“…Heterostructured catalysts not only integrate the merits of single components but also show synergistic effects among these single components to further decrease the kinetic energy barriers of catalytic reaction, such as Ni 2 P/Fe 2 P, MoS 2 /Ni 3 S 2 , FeOOH/Co/FeOOH, Co 3 O 4 /Fe 0.33 Co 0.66 P, Ni@C-V 2 O 3 /NF, (Ni–WO 2 )@C/NF, and Ni–NiO–Mo 0.84 Ni 0.16 /NF . For example, Yin and co-workers prepared villous FeNi 3 –MoO 2 heterojunction nanosheet array on a self-supported nickel foam (NF) as a bifunctional catalyst, which showed good hydrogen evolution and urea oxidation performance .…”