The use of surfactants in enhanced oil recovery: A review of recent advances

NiCo-Based Electrocatalysts for the Alkaline Oxygen Evolution Reaction: A Review

Preparing efficient and stable catalysts is one of the most urgent problems for water splitting. Herein, IrNi-FeNi3 hybrid self-supported on nickel foam with unique nanosheets and 1.218 wt.% Ir-loading is synthesized via hydrothermal method. In 1.0 M KOH, ultralow overpotentials for oxygen evolution reaction (OER, η20 = 240.0 mV, η1000 = 330.0 mV) and hydrogen evolution reaction (HER, η10 = 31.1 mV, η1000 = 288.8 mV) are needed. Only 1.47 V is required for overall water splitting to arrive at 10 mA cm−2, indicating superior activity. For overall water splitting, it also demonstrates good stability with negligible declines after testing for 100 h at 500 mA cm−2 in 6.0 M KOH at 60 ℃, which is close to the practical application. The unique self-supported nanosheets structure on nickel foam can expose more active sites and the hybridization of IrNi with FeNi3 can promote the intrinsic activity of catalyst. Therefore, this work proposes an industrially promising catalyst for water splitting.

Industrially promising IrNi-FeNi3 hybrid nanosheets for overall water splitting catalysis at large current density

Self-Supported Electrocatalysts for Practical Water Electrolysis

Developing highly effective and stable non-noble metal-based bifunctional catalyst working at high current density is an urgent issue for water electrolysis (WE). Herein, we prepare the N-doped graphene-decorated NiCo alloy coupled with mesoporous NiCoMoO nano-sheet grown on 3D nickel foam (NiCo@C-NiCoMoO/NF) for water splitting. NiCo@C-NiCoMoO/NF exhibits outstanding activity with low overpotentials for hydrogen and oxygen evolution reaction (HER: 39/266 mV; OER: 260/390 mV) at ± 10 and ± 1000 mA cm−2. More importantly, in 6.0 M KOH solution at 60 °C for WE, it only requires 1.90 V to reach 1000 mA cm−2 and shows excellent stability for 43 h, exhibiting the potential for actual application. The good performance can be assigned to N-doped graphene-decorated NiCo alloy and mesoporous NiCoMoO nano-sheet, which not only increase the intrinsic activity and expose abundant catalytic activity sites, but also enhance its chemical and mechanical stability. This work thus could provide a promising material for industrial hydrogen production.

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N-Doped Graphene-Decorated NiCo Alloy Coupled with Mesoporous NiCoMoO Nano-sheet Heterojunction for Enhanced Water Electrolysis Activity at High Current Density

Developing efficient bifunctional water electrolysis catalysts applied at large current density is desirable. Herein, an amorphous CoOx-decorated crystalline RuO2 nanosheet catalyst self-supported ...

Amorphous CoOx-Decorated Crystalline RuO2 Nanosheets as Bifunctional Catalysts for Boosting Overall Water Splitting at Large Current Density

PtCo@PtSn Heterojunction with High Stability/Activity for pH-Universal H2 Evolution

Urea electrolysis is a cost-effective method for urea-rich wastewater degradation to achieve a pollution-free environment. In this work, the Ni3S2/Ni heterostructure nanobelt arrays supported on nickel foam (Ni3S2/Ni/NF) are synthesized for accelerating the urea oxidation reaction (UOR) and hydrogen evolution reaction (HER). It only needs ultralow potentials of 1.30 V and -54 mV to achieve the current density of ±10 mA cm-2 for UOR and HER, respectively. Meanwhile, the overall urea oxidation driven by Ni3S2/Ni/NF only needs 1.36 V to achieve 10 mA cm-2, and it can remain at 100 mA cm-2 for 60 h without obvious activity attenuation. The superior performance could be attributed to the heterostructure between Ni3S2 and Ni, which can promote electron transfer and form electron-poor Ni species to optimize urea decomposition and hydrogen production. Moreover, the nanobelt self-supported structure could expose abundant active sites. This work thus provides a feasible and cost-effective strategy for urea-rich wastewater degradation and hydrogen production.

Ni3S2/Ni Heterostructure Nanobelt Arrays as Bifunctional Catalysts for Urea-Rich Wastewater Degradation.

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.

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

Jinli Chen

Papers

N-Doped Graphene-Decorated NiCo Alloy Coupled with Mesoporous NiCoMoO Nano-sheet Heterojunction for Enhanced Water Electrolysis Activity at High Current Density

Amorphous CoOx-Decorated Crystalline RuO2 Nanosheets as Bifunctional Catalysts for Boosting Overall Water Splitting at Large Current Density

PtCo@PtSn Heterojunction with High Stability/Activity for pH-Universal H2 Evolution

Ni3S2/Ni Heterostructure Nanobelt Arrays as Bifunctional Catalysts for Urea-Rich Wastewater Degradation.

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