In-situ integration of nickel-iron Prussian blue analog heterostructure on Ni foam by chemical corrosion and partial conversion for oxygen evolution reaction

Complementary dual-modal immunosensing strategy for accurate detecting zearalenone based on bimetallic NiFe-Prussian blue analogue

In this work, a complementary dual-modal immunosensing strategy was fabricated for the sensitive and selective detection of zearalenone (ZEN) by integrating immunochromatographic and electrochemical biosensing methods. For this, bimetallic NiFe Prussian blue analogue (NiFe-PBA) was simultaneously employed as a matrix for labelling ZEN-targeted antibody and the sensitive layer for anchoring antibody to construct an efficient immunochromatographic immunosensor (ICI) and electrochemical immunosensor (ECI), respectively. Due to porous network, good functionality, high bioaffinity, and rich metal redox, NiFe-PBA-based complementary dual-modal immunosensor exhibited low limit of detection, high selectivity and stability, and accepted practicality. Particularly, the developed ECI illustrated fast response, portability, and potentially commercial application. Coupling the ICI and ECI sensing strategy can markedly enhance the accuracy and sensitive detection of ZEN in complicated environments. This dual-modal ICI-ECI immunosensing strategy exhibits significant potential for the precise detection of mycotoxin in various agricultural products and improve the quality control for foods.

In situ integration of bimetallic NiFe Prussian blue analogs on carbon cloth for the oxygen evolution reaction

This study develops a cost-effective strategy to integrate the bimetal NiFe Prussian blue analog (PBA) on carbon cloth (NFPB@CC) as a highly-active oxygen evolution reaction (OER) hybrid catalyst. NFPB@CC possesses abundant unsaturated metal active sites, with a low OER overpotential of only 332 mV and a low Tafel slope of 78 mV dec-1 at 10 mA cm-1.

In-Situ Construction of Fe-Doped NiOOH on the 3D Ni(OH)2 Hierarchical Nanosheet Array for Efficient Electrocatalytic Oxygen Evolution Reaction

Accessible and superior electrocatalysts to overcome the sluggish oxygen evolution reaction (OER) are pivotal for sustainable and low-cost hydrogen production through electrocatalytic water splitting. The iron and nickel oxohydroxide complexes are regarded as the most promising OER electrocatalyst attributed to their inexpensive costs, easy preparation, and robust stability. In particular, the Fe-doped NiOOH is widely deemed to be superior constituents for OER in an alkaline environment. However, the facile construction of robust Fe-doped NiOOH electrocatalysts is still a great challenge. Herein, we report the facile construction of Fe-doped NiOOH on Ni(OH)2 hierarchical nanosheet arrays grown on nickel foam (FeNi@NiA) as efficient OER electrocatalysts through a facile in-situ electrochemical activation of FeNi-based Prussian blue analogues (PBA) derived from Ni(OH)2. The resultant FeNi@NiA heterostructure shows high intrinsic activity for OER due to the modulation of the overall electronic energy state and the electrical conductivity. Importantly, the electrochemical measurement revealed that FeNi@NiA exhibits a low overpotential of 240 mV at 10 mA/cm2 with a small Tafel slope of 62 mV dec-1 in 1.0 M KOH, outperforming the commercial RuO2 electrocatalysts for OER.

From lab to field: Prussian blue frameworks as sustainable cathode materials

Prussian blue and Prussian blue analogues have attracted increasing attention as versatile framework materials with a wide range of applications in catalysis, energy conversion and storage, and biomedical and environmental fields. In terms of energy storage and conversion, Prussian blue-based materials have emerged as suitable candidates of growing interest for the fabrication of batteries and supercapacitors. Their outstanding electrochemical features such as fast charge-discharge rates, high capacity and prolonged cycling life make them favorable for energy storage application. Furthermore, Prussian blue and its analogues as rechargeable battery anodes can advance significantly by the precise control of their structure, morphology, and composition at the nanoscale. Their tunable structural and electronic properties enable the detection of many types of analytes with high sensitivity and specificity, and thus, they are ideal materials for the development of sensors for environmental detection, disease trend monitoring, and industrial safety. Additionally, Prussian blue-based catalysts display excellent photocatalytic performance for the degradation of pollutants and generation of hydrogen. Specifically, their excellent light capturing and charge separation capabilities make them stand out in photocatalytic processes, providing a sustainable option for environmental remediation and renewable energy production. Besides, Prussian blue coatings have been studied particularly for corrosion protection, forming stable and protective layers on metal surfaces, which extend the lifespan of infrastructural materials in harsh environments. Prussian blue and its analogues are highly valuable materials in healthcare fields such as imaging, drug delivery and theranostics because they are biocompatible and their further functionalization is possible. Overall, this review demonstrates that Prussian blue and related framework materials are versatile and capable of addressing many technical challenges in various fields ranging from power generation to healthcare and environmental management.

Integrating Amorphous Molybdenum Sulfide Nanosheets with a Co9S8@Ni3S2 Array as an Efficient Electrocatalyst for Overall Water Splitting

It is highly challenging to design low-cost, efficient electrocatalysts for both oxygen evolution reaction (OER) and hydrogen evolution reaction (HER). Herein, a hierarchical heterostructure was constructed on three-dimensional (3D) Ni foam, which contains Ni₃S₂ nanorods decorated with both Co₉S₈ and amorphous MoS_x nanosheets and Ni₃S₂ nanowires decorated with amorphous MoS_x nanosheets, namely, MoS_x@Co₉S₈@Ni₃S₂/NF. The synergistic effects from the strong interactions of the heterointerface and unique hierarchical heterostructure endow the MoS_x@Co₉S₈@Ni₃S₂/NF with abundant active sites and effective mass and electron transport pathways, resulting in excellent activity toward both HER and OER in 1 M KOH. It only gives a low overpotential of 76.5 mV to achieve 10 mA cm^-2 for HER and a low overpotential of 310 mV to achieve 100 mA cm^-2 for OER. Based on the superior catalytic activity of MoS_x@Co₉S₈@Ni₃S₂/NF for OER and HER, we demonstrated the activity of overall water splitting using MoS_x@Co₉S₈@Ni₃S₂/NF as both the anode and cathode. It shows a higher catalytic activity for overall water splitting with a low cell voltage of 1.52 V at 10 mA cm^-2 than commercial Pt/C/NF||IrO₂/NF (1.61 V) and superior stability. This work provides a platform for the design and preparation of efficient electrocatalysts with various hierarchical heterostructures.

Spherical Ni3 S2 /Fe-NiPx Magic Cube with Ultrahigh Water/Seawater Oxidation Efficiency

The rational construction of earth-abundant and advanced electrocatalysts for oxygen evolution reaction (OER) is extremely desired and significant to seawater electrolysis. Herein, by directly etching Ni₃ S₂ nanosheets through potassium ferricyanide, a novel self-sacrificing template strategy is proposed to realize the in situ growth of NiFe-based Prussian blue analogs (NiFe PBA) on Ni₃ S₂ in an interfacial redox reaction. The well-designed Ni₃ S₂ @NiFe PBA composite as precursor displays a unique spherical magic cube architecture composed of nanocubes, which even maintains after a phosphating treatment to obtain the derived Ni₃ S₂ /Fe-NiP_x on nickel foam. Specifically, in alkaline seawater, the Ni₃ S₂ /Fe-NiP_x as OER precatalyst marvelously realizes the ultralow overpotentials of 336 and 351 mV at large current densities of 500 and 1000 mA cm^-2 , respectively, with remarkable durability for over 225 h, outperforming most reported advanced OER electrocatalysts. Experimentally, a series of characterization results confirm the reconstruction behavior in the Ni₃ S₂ /Fe-NiP_x surface, leading to the in situ formation of Ni(OH)₂ /Ni(Fe)OOH with abundant oxygen vacancies and grain boundaries, which constructs the Ni₃ S₂ /Fe-NiP_x reconstruction system responsible for the remarkable OER catalytic activity. Theoretical calculation results further verify the enhanced OER activity for Ni₃ S₂ /Fe-NiP_x reconstruction system, and unveil that the Fe-Ni₂ P/FeOOH as active origin contributes to the central OER activity.