Smartphone Imaging Device for Multimodal Detection of Hydrogen Sulfide Using Cu-Doped MOF Sensors.

Multimodal sensing platforms may offer reliable, fast results, but it is still challenging to incorporate biosensors with high discriminating ability in complex biological samples. Herein, we established a highly sensitive dual colorimetric/electrochemical monitoring approach for the detection of hydrogen sulfide (H2S) utilizing Cu-doped In-based metal-organic frameworks (Cu/In-MOFs) combined with a versatile color selector software-based smartphone imaging device. H2S can result in the enhancement of the electrochemical signal because of the electroactive substance copper sulfide (CuxS), the decrease of the colorimetric signal of the characteristic absorption response caused by the strong coordination effect on Cu/In-MOFs, and the obvious changes of red-green-blue (RGB) values of images acquired via an intelligent smartphone. Attractively, the Cu/In-MOFs-based multimodal detection guarantees precise and sensitive detection of H2S with triple-signal detection limits of 0.096 µM (electrochemical signals), 0.098 µM (colorimetric signals), and 0.099 µM (smartphone signals) and an outstanding linear response. This analytical toolkit provides an idea for fabricating a robust, sensitive, tolerant matrix and reliable sensing platform for rapidly monitoring H2S in clinical disease diagnosis and visual supervision.

Electrochemical sensor for hydrogen sulfide detection using electrocatalysis-assisted amplification and chemical reaction-mediated signal enhancement.

An ultrasensitive electrochemical biosensing platform has been designed by combining electrocatalysis-assisted H2S amplification with a chemical reaction-mediated electrochemical signal-boosted system for H2S detection based on Cu-Mn(OH)2 hexagonal nanorings. The signal amplification is initiated by an electrocatalysis reaction that can grasp specific H2S substrates and further highly amplify electrochemical signals. Then, the unique chemical reaction is powered by copper ion and generates a large amount of electroactive CuxS products on the electrode surface, thus achieving the multiple amplification of H2S detection. Finally, the Cu-Mn(OH)2 loaded with plenty of electroactive CuxS can be captured on the electrode for further improving the electrochemical signal thus obtaining ultra-high sensitive determination of H2S. The established electrochemical biosensing platform displays a wide analytical range of 0.1 µM to 265 µM with a low detection limit of 0.096 µM. The satisfactory selectivity allows the electrochemical sensor to distinguish H2S from other interfering substances without any complicated pretreatment, even in complex tumor cell samples. Thus, our designed electrocatalysis-assisted amplification strategy offers a powerful analysis toolkit for the early determination of H2S-related disease in clinical diagnosis.

A smartphone-assisted colorimetric and photothermal probe for glutathione detection based on enhanced oxidase-mimic CoFeCe three-atom nanozyme in food.

The rational fabrication of point-of-care testing (POCT) featuring simplicity, rapidity, low cost, portability, high sensitivity and accuracy is crucial for maintaining food safety in resource-limited locations and home healthcare but remains challenging. Herein, we report a universal colorimetric-photothermal-smartphone triple-mode sensing platform for POC food-grade glutathione (GSH) detection. This simple sensing platform for GSH detection takes merits of three techniques: commercially available filter paper, thermometer and smartphone via an excellent CoFeCe-mediated oxidase-like activity. This strategy allows CoFeCe three-atom hydroxide to efficiently convert dissolved oxygen into O2·- and catalyzes 3, 3', 5, 5'-tertamethylbenzidine (TMB) to generate an oxidized TMB with remarkable color changes and photothermal effect, resulting in a colorimetric-temperature-color triple-mode signal output. The constructed sensor exhibits high sensitivity with a limit of detection of 0.092 µM for GSH detection. We expect this sensing platform can be easily modified for the determination of GSH in commercial samples with the simple testing strips.

Dual-mode biosensor platform based on synergistic effects of dual-functional hybrid nanomaterials.

Detection of biomarkers is very vital in the prevention, diagnosis and treatment of diseases. However, due to the poor accuracy and sensitivity of the constructed biosensors, we are now facing great challenges. In addressing these problems, nanohybrid-based dual mode biosensors including optical-optical, optical-electrochemical and electrochemical-electrochemical have been developed to detect various biomarkers. Integrating the merits of nanomaterials with abundant active sites, synergy and excellent physicochemical properties, many bi-functional nanohybrids have been reasonable designed and controllable preparation, which applied to the construction dual mode biosensors. Despite the significant progress, further efforts are still needed to develop dual mode biosensors and ensure their practical application by using portable digital devices. Therefore, the present review summarizes an in-depth evaluation of the bi-functional nanohybrids assisted dual mode biosensing platform of biomarkers. We are hoping this review could inspire further concepts in developing novel dual mode biosensors for possible detection application.

Dual-mode biosensing platform for sensitive and portable detection of hydrogen sulfide based on cuprous oxide/gold/copper metal organic framework heterojunction.

Hydrogen sulfide (H2S) can not only be regarded as a critical gas signal transduction substance, but also its excess levels can lead to a range of diseases. Currently, the accurate analysis combined with electrochemical (EC) or photothermal (PT) technology for H2S in a complex biological system remains a significant challenge. Herein, an endogenous H2S-triggered heterojunction cuprous oxide/gold/copper metal organic framework (Cu2O/Au/HKUST-1) nanoprobe is designed for dual-mode EC- second near-infrared (NIR-II)/PT analysis in tumor cells with high sensitivity and simplicity. Dual-mode EC quantification - PT is achieved through "off-on" mode of EC and PT signals based on electronic transfer and biosynthesis via an in situ sulfuration reaction. Under the optimum conditions, the EC quantification mode for trace H2S exhibits a wide linear range and an excellent limit of detection of 0.1 µM. More importantly, the dual-mode can display the selective detection of trace H2S in living tumor cells because of the specific interaction between copper ion and H2S. These results provide a new EC-PT promising biosensing platform for noninvasive intelligent detection of H2S in living tumor cells.

Biosynthesis-mediated Ni-Fe-Cu LDH-to-sulfides transformation enabling sensitive detection of endogenous hydrogen sulfide with dual-readout signals.

Hydrogen sulfide (H2S) is a vital endogenous gas signal molecule undertaking numerous physiological functions such as biological regulation and cytoprotection. Herein, we developed an electrochemical (EC) and photothermal (PT) dual-readout signals method for H2S detection based on a novel biosynthesis-mediated Ni-Fe-Cu LDH-to-sulfides transformation strategy. Interestingly, the Cu2+-based Ni-Fe LDH (Ni-Fe-Cu LDH) can act as the Cu2+ source to react with H2S, resulting in the in-situ generation of CuxS on Ni-Fe-Cu LDH surfaces. Because of the EC signal and intrinsic near-infrared (NIR) PT conversion ability of CuxS under 808 nm laser irradiation, the obtained CuxS@Ni-Fe-Cu LDH is applied to stimulate EC signal and temperature readout. By this means, a dual-readout signal mode is established for H2S detection. Under the optimum conditions, this combination of EC and PT methods displays a wide linear range for H2S to 0.1 µM-90 µM and 50 µM-400 µM, respectively, with a low detection limit of 0.09 µM. In addition, the practicality of Ni-Fe-Cu LDH is verified by determination of endogenous H2S in living cells. This work not only provides a promising application for H2S diagnosis but also exhibits the new characteristic of Ni-Fe-Cu LDH nanomaterials as signal transduction tags.

Tumor acidity and near-infrared light responsive drug delivery MoS2-based nanoparticles for chemo-photothermal therapy.

The rational design of tumor microenvironment (TME)- multifunctional stimuli-responsive nanocomposites is appealing for effective cancer treatment. However, multidrug resistance remains an obstacle to construct responsive oncotherapy. Herein, a novel MoS2/PDA-TPP nanocomposite loaded with chemotherapy drug of doxorubicin (DOX) is designed for TME dual-response and synergistically enhanced anti-tumor therapy based on the tumor-specific mitochondria accumulation ability and photothermal (PTT) therapy. In detail, the designed MoS2/PDA-TPP nanoplatform can act as a pH-responsive dissociation to endow fast release of DOX under an acidic TME and simultaneously improve the efficiency of PTT. Moreover, the mechanism shows that MoS2/PDA-TPP trigger mitochondrial-dependent apoptosis by producing reactive oxygen species (ROS) and reducing mitochondrial membrane potential (MMP). Most importantly, during PTT procedure, hyperthermia up to 50 °C can effectively induce tumor cell death without causing severe inflammation to adjacent tissues. Tumor targeting double stimulation response of nanocomposites is a novel idea to overcome drug resistance, which will provide a more effective strategy for solving practical problems.

Self-driven Ru-modified NiFe MOF nanosheet as multifunctional electrocatalyst for boosting water and urea electrolysis.

Urea electro-oxidation reaction (UOR) has been a promising strategy to replace oxygen evolution reaction (OER) by urea-mediated water splitting for hydrogen production. Naturally, rational design of high-efficiency and multifunctional electrocatalyst towards UOR and hydrogen evolution reaction (HER) is of vital significance, but still a grand challenge. Herein, an innovative 3D Ru-modified NiFe metal-organic framework (MOF) nanoflake array on Ni foam (Ru-NiFe-x/NF) was elaborately designed via spontaneous galvanic replacement reaction (GRR). Notably, the adsorption capability of intermediate species (H*) of catalyst is significantly optimized by Ru modification. Meanwhile, rich high-valence Ni active species can be acquired by self-driven electronic reconstruction in the interface, then dramatically accelerating the electrolysis of water and urea. Remarkably, the optimized Ru-NiFe-③/NF (1.6 at% of Ru) only requires the overpotential of 90 and 310 mV to attain 100 mA cm-2 toward HER and OER in alkaline electrolyte, respectively. Impressively, an ultralow voltage of 1.47 V is required for Ru-NiFe-③/NF to deliver a current density of 100 mA cm-2 in urea-assisted electrolysis cell with superior stability, which is 190 mV lower than that of Pt/C-NF||RuO2/NF couple. This work is desired to explore a facile way to exploit environmentally-friendly energy by coupling hydrogen evolution with urea-rich sewage disposal.

3D Porous Ru-Doped NiCo-MOF Hollow Nanospheres for Boosting Oxygen Evolution Reaction Electrocatalysis.

Developing high-performance and cost-efficient catalysts toward oxygen evolution reaction (OER) is an important but daunting task due to the sluggish kinetics hindered by the four-electron transfer process. Herein, an advanced class of ultralow Ru-doped NiCo-MOF hollow porous nanospheres (denoted as Ru@NiCo-MOF HPNs) has been reported in this work. Benefiting from the high porosity and large surface area of the metal-organic frameworks (MOFs) and optimized electronic properties by Ru doping, the as-prepared Ru@NiCo-MOF HPNs exhibit superior performance for water oxidation with the overpotential of only 284 mV to reach a current density of 10 mA·cm-2 in alkaline electrolyte, as well as a small Tafel slope of 78.8 mV·dec-1, outperforming the NiCo-MOF HPNs (358 mV) and commercial RuO2 catalyst (326 mV). The incorporation of Ru in NiCo-MOF HPNs enables a stable OER activity for at least 39 h. Moreover, we have probed the interaction between the content of Ru and OER performance, impressively, Ru@NiCo-MOF HPNs with 13.5 atom % Ru doping (denoted as Ru@NiCo-MOF-4) exhibited the highest OER activity with the excellent mass activity of 310 mA·mg-1 at an overpotential of 284 mV. Besides, a two-electrode cell with Ru@NiCo-MOF-4 as the anode and commercial Pt/C catalyst as the cathode also demonstrated outstanding electrocatalytic overall water splitting performance with a cell potential of merely 1.57 V to deliver a current density of 10 mA·cm-2.

A general MOF-intermediated synthesis of hollow CoFe-based trimetallic phosphides composed of ultrathin nanosheets for boosting water oxidation electrocatalysis.

Engineering an electrode material for boosting reaction kinetics is highly desired for the oxygen evolution reaction (OER) in the anodic half reaction, and is still a grand challenge for energy conversion technologies. By taking inspiration from the catalytic properties of transition metal phosphides (TMPs) and metal-organic frameworks (MOFs), we herein propose a general MOF-intermediated synthesis of a series of hollow CoFeM (M = Bi, Ni, Mn, Cu, Ce, and Zn) trimetallic phosphides composed of ultrathin nanosheets as advanced electrocatalysts for the OER. A dramatic improvement of electrocatalytic performance toward the OER is observed for hollow CoFeM trimetallic phosphides compared to bimetallic CoFe phosphides. Remarkably, composition-optimized CoFeBiP hollow microspheres could deliver superior electrocatalytic performance, achieving a current density of 10 mA cm-2 with an overpotential of only 273 mV. Mechanistic investigations reveal that the Bi and P doping effectively optimizes the electronic structure of Co and Fe by charge redistribution, which significantly lowers the adsorption energy of oxygen intermediates. Moreover, the hollow microsphere structures composed of ultrathin nanosheets also enable them to provide rich surface active sites to boost the electrocatalytic OER.

Advances in hydrogen production from electrocatalytic seawater splitting.

As one of the most abundant resources on the Earth, seawater is not only a promising electrolyte for industrial hydrogen production through electrolysis, but also of great significance for the refining of edible salt. Despite the great potential for large-scale hydrogen production, the implementation of water electrolysis requires efficient and stable electrocatalysts that can maintain high activity for water splitting without chloride corrosion. Recent years have witnessed great achievements in the development of highly efficient electrocatalysts toward seawater splitting. Starting from the historical background to the most recent achievements, this review will provide insights into the current state, challenges, and future perspectives of hydrogen production through seawater electrolysis. In particular, the mechanisms of overall water splitting, key features of seawater electrolysis, noble-metal-free electrocatalysts for seawater electrolysis and the underlying mechanisms are also highlighted to provide guidance for fabricating more efficient electrocatalysts toward seawater splitting.

Recent Progress of Ultrathin 2D Pd-Based Nanomaterials for Fuel Cell Electrocatalysis.

Pd- and Pd-based catalysts have emerged as potential alternatives to Pt- and Pt-based catalysts for numerous electrocatalytic reactions, particularly fuel cell-related reactions, including the anodic fuel oxidation reaction (FOR) and cathodic oxygen reduction reaction (ORR). The creation of Pd- and Pd-based architectures with large surface areas, numerous low-coordinated atoms, and high density of defects and edges is the most promising strategy for improving the electrocatalytic performance of fuel cells. Recently, 2D Pd-based nanomaterials with single or few atom thickness have attracted increasing interest as potential candidates for both the ORR and FOR, owing to their remarkable advantages, including high intrinsic activity, high electron mobility, and straightforward surface functionalization. In this review, the recent advances in 2D Pd-based nanomaterials for the FOR and ORR are summarized. A fundamental understanding of the FOR and ORR is elaborated. Subsequently, the advantages and latest advances in 2D Pd-based nanomaterials for the FOR and ORR are scientifically and systematically summarized. A systematic discussion of the synthesis methods is also included which should guide researchers toward more efficient 2D Pd-based electrocatalysts. Lastly, the future outlook and trends in the development of 2D Pd-based nanomaterials toward fuel cell development are also presented.

Dual mode electrochemical-photoelectrochemical sensing platform for hydrogen sulfide detection based on the inhibition effect of titanium dioxide/bismuth tungstate/silver heterojunction.

A novel dual mode sensing platform is constructed for highly selective detection of H2S, attributing to the efficient electrochemical (EC) and photoelectrochemical (PEC) signal responses of the TiO2/Bi2WO6/Ag heterojunction. On the one hand, TiO2/Bi2WO6/Ag heterojunction with excellent catalytic performance for the reduction of H2O2 could be employed act as a probe, providing a remarkable EC response through an amperometric i-t method. On the other hand, this hybrid provides a photoelectric beacon with a favorable energy-band configuration. More interestingly, the EC and PEC responses of the functionalized electrodes are proportionately decreased in response to the generation of Bi2S3 and Ag2S nanoparticles upon exposure to sulfide ions. The decreased EC and PEC signals could be ascribed to the poor catalytic properties and the recombination of photoexcited electron - hole pairs of the Bi2S3 and Ag2S. Under the optimal conditions, the dual mode sensor exhibits a wide linear response in the range from 0.5 µM to 300 µM with a detection limit of 0.08 µM for the detection of H2S. Enabled by this unique sensitization mechanism, the proposed sensing platform displays an excellent analytical performance with good selectivity, reproducibility and stability, which providing an alternative pathway of H2S detecting in practical application.

Multi-dimensional collaboration promotes the catalytic performance of 1D MoO3 nanorods decorated with 2D NiS nanosheets for efficient water splitting.

The ability to manipulate heterostructures is of great importance to achieve high-performance electrocatalysts for direct water-splitting devices with excellent activity toward hydrogen production. Herein, a novel top-down strategy involving the in situ transformation of one-dimensional MoO3 nanorod arrays grafted with two-dimensional NiS nanosheets supported on a three-dimensional nickel foam skeleton is proposed. Namely, a heterostructured electrocatalyst on the Ni foam skeleton containing MoO3 nanorod arrays decorated with NiS nanosheets is synthesized by a facile hydrothermal method followed by one-step sulfidation treatment. Experimental analysis confirmed that this novel composite has the merits of a large quantity of accessible active sites, unique distribution of three different spatial dimensions, accelerated mass/electron transfer, and the synergistic effect of its components, resulting in impressive electrocatalytic properties toward the hydrogen evolution reaction and oxygen evolution reaction. Furthermore, an advanced water-splitting electrolyzer was assembled with NiS/MoO3/NF as both the anodic and cathodic working electrode. This device requires a low cell voltage of 1.56 V to afford a water-splitting current density of 10 mA·cm-2 in basic electrolyte, outperforming previously reported electrocatalysts and even state-of-the-art electrocatalysts. More significantly, this work provides a way to revolutionize the design of heterostructured electrocatalysts for the large-scale commercial production of hydrogen using direct water-splitting devices.

Hollow V-Doped CoMx (M = P, S, O) Nanoboxes as Efficient OER Electrocatalysts for Overall Water Splitting.

Hollow nanostructures with intricate interior and catalytic effects have been the focus of researchers in energy conversion and storage. Although tremendous efforts have been made, the fabrication of well-defined hollow nanostructures has been rarely reported due to the limitations of the synthetic methods. Herein, we have proposed a general synthetic strategy for the construction of V-doped CoMx (M = P, S, O) nanoboxes (NBs), where the doped V effectively modifies the electronic structure of CoMx to provide a favorable surface electrochemical environment for the adsorption of reaction intermediates (*O, *OH, and *OOH), leading to a significant enhancement in electrocatalytic performance. More importantly, the hollow nanostructures can expose abundant surface active areas and promote the chemical adsorption of reactants and intermediates, greatly contributing to the promotion of electrocatalytic performance. Impressively, the optimal V-doped CoS2 NBs show excellent electrocatalytic oxygen evolution reaction (OER) performance with an overpotential of only 290 mV at 10 mA cm-2, along with outstanding overall water-splitting performance. This work supplies pivotal insights for constructing high-performance OER catalysts on the basis of electronic and geometric engineering.

3D ZnIn2S4 nanosheets decorated ZnCdS dodecahedral cages as multifunctional signal amplification matrix combined with electroactive/photoactive materials for dual mode electrochemical - photoelectrochemical detection of bovine hemoglobin.

The construction of dual mode sensor has gained tremendous attention due to its high accuracy and sensitivity compared with a single-response system. Herein, a novel dual mode sensing platform based on a 3-dimensional (3D) ZnCdS/ZnIn2S4 double-shelled dodecahedral cages (DSDCs) is fabricated as the electrochemical (EC) - photoelectrochemical (PEC) multifunctional signal amplification matrix for the highly selective detection of bovine hemoglobin (BHb). To achieve simple and fast detection of BHb, Au@Cu2O and SnO2/SnS2 are acted as EC - PEC signal indicators, respectively. More interestingly, the electroactive Au@Cu2O and photoactive SnO2/SnS2 are assembled on the 3D ZnCdS/ZnIn2S4 DSDCs, which could effectively increase the electron transfer process, consequently amplifying the readout of the dual mode responses. Besides, polydopamine (PDA) is used as a monomer for protein imprinting. Under the optimized conditions, the dual mode sensor exhibits a wide linear concentration range from 10-19 mg mL-1 to 10-1 mg mL-1 with a low detection limit 6.5 × 10-20 mg mL-1. Furthermore, the excellent selectivity, stability and acceptable reproducibility of the designed sensor will offer an alternation for the detection of other biomacromolecules in clinic diagnosis field.

Efficient polyalcohol oxidation electrocatalysts enabled by PtM (M = Fe, Co, and Ni) nanocubes surrounded by (200) crystal facets.

Due to the high-density (200) crystal planes and abundant active sites, cubic platinum nanomaterials have become outstanding electrocatalysts in promoting fuel cell reactions. However, because of the fact that the facet-controlled synthesis is difficult, it is still a grand challenge to synthesize a sequence of Pt-based nanocubes via a universal method. Herein, we report a general and simple eco-friendly solvothermal method to prepare (200)-enclosed PtM nanocubes. Different from the other nanomaterials, nanocubes are conducive to mass transfer. Moreover, the synergistic and electronic effects between M and Pt are profitable to improve the utilization of precious metals. We used (200)-encapsulated nanocrystals to evaluate their electrocatalytic performance towards glycerol and ethylene glycol oxidation reactions in an alkaline medium. In particular, Pt4Co nanocubes showed superior mass activities in glycerol and ethylene glycol oxidation reactions, which are 6.2- and 5.0-fold higher than those obtained for commercial Pt/C catalysts, respectively. Meanwhile, Pt4M catalysts manifested excellent stability in the endurance test, which is attributed to the alloying effect promoting the electrooxidation of intermediates. Our study provides an ideal method for the construction of Pt-based bimetallic nanocubes, which can be used for anode reactions of polyol fuel cells and beyond.

Ir-Doped Pd Nanosheet Assemblies as Bifunctional Electrocatalysts for Advanced Hydrogen Evolution Reaction and Liquid Fuel Electrocatalysis.

Although great progress in pursuing high-performance catalysts for advanced electrocatalysis has been made, the design of high-efficiency electrocatalysts continues to be a huge challenge for commercializing electrochemical energy technologies. Herein, a three-dimensional (3D) hierarchical assembly nanostructure consisting of ultrathin Ir-doped Pd nanosheets has been well designed, which could serve as a bifunctional electrocatalyst for advanced hydrogen evolution reaction (HER) and liquid fuel electrooxidation. In particular, the optimized Pd83.5Ir16.5 nanocatalyst displays excellent electrocatalytic HER performance with an overpotential of only 73 mV at 10 mA cm-2 along with excellent stability. More importantly, it can also show outstanding electrocatalytic performance for liquid fuel oxidation with a mass activity of 4326.1 mA mgmetal-1 for ethylene glycol oxidation reaction. Mechanistic study reveals that the highly porous 3D nanostructure, the modulation of electronic structure after the introduction of Ir, not only guarantees a high level of exposure of surface active sites and smooth charge transfer but also generates the new active centers for facilitating the adsorption of H2O and recombination of H*, thereby dramatically increasing the intrinsic activity of electrocatalysis.

General synthesis of Pd-pm (pm = Ga, In, Sn, Pb, Bi) alloy nanosheet assemblies for advanced electrocatalysis.

Owing to the synergistic compositional and structural advantages, ultrathin bimetallic nanosheet assembly nanostructures are widely recognized as advanced catalysts for alcohol electrooxidation reaction. Although numerous efforts have been made, the fabrication of well-defined ultrathin bimetallic nanosheet assemblies (NSAs) at large scale is still a tough challenge. Herein, a universal synthetic approach has been proposed to produce a series of well-defined Pd-pm (pm = Ga, In, Sn, Pb, Bi) alloy NSAs. Due to multiple merits of their unique 3D flower-like nanostructure and alloyed crystalline features, the self-supported Pd-pm NSAs show excellent electrocatalytic performance for the methanol oxidation reaction (MOR) and glycerol oxidation reaction (GOR). Given the eco-friendly synthetic concept, facile universality, and outstanding electrocatalytic properties of the generated bimetallic Pd-pm NSAs, we believe that this method could be employed for building more advanced nanocatalysts toward efficient electrocatalytic applications.

Nanoscale engineering of porous Fe-doped Pd nanosheet assemblies for efficient methanol and ethanol electrocatalyses.

Although great successes have been accomplished on the controlled synthesis of 2D and 3D Pd-containing nanomaterials, tapping into the novel Pd-containing electrocatalysts that combined the advantages of both 2D and 3D structures remains a significant challenge. Here, an approach to systematically produce porous Fe-doped Pd nanosheet assemblies (NSAs) with a geometry tuning from PdFe hollow nanospheres (HNSs), PdFe nanocages (NCs), to PdFe nanoplates (NPs) is reported. The inherent ultrathin and porous features endow these PdFe catalysts with excellent electrocatalytic performance. As a result, the optimized 3D PdFe NCs show a much-improved methanol oxidation reaction (MOR) and ethanol oxidation reaction (EOR) activities in comparison with PdFe HNSs, Pd NPs, and commercial Pd/C catalysts. Moreover, these PdFe nanocatalysts also display greatly enhanced electrocatalytic stability, which can endure 500 cycles with negligible activity loss and structural changes. The mechanism investigations reveal that the introduced Fe atom efficiently modulates the electronic structure of Pd, leading to the downshift of the d-band center of Pd, which is beneficial for the adsorption of reactants. Moreover, the porous nanosheet assembly structure can provide rich mass and electron transfer channels, further boosting the improvement of electrocatalytic performance.