Pt quantum dots coupled with NiFe LDH nanosheets for efficient hydrogen evolution reaction at industrial current densities
0 Abstract
Developing efficient and economical electrocatalysts for hydrogen generation at high current densities is crucial for advancing energy sustainability. Herein, a self-supported hydrogen evolution reaction (HER) electrocatalyst is rationally designed and prepared on a nickel foam through a simple two-step chemical etching method, which consists of Pt quantum dots (PtQDs) coupled with nickel-iron layered double hydroxide (NiFe LDH) nanosheets (named PtQDs@NiFe LDH). The characterization results indicate that the introduction of PtQDs induces more oxygen vacancies, thereby optimizing the electronic structure of PtQDs@NiFe LDH. This modification enhances the conductivity and accelerates the adsorption/desorption kinetics of hydrogen intermediates in PtQDs@NiFe LDH, ultimately resulting in exceptional catalytic performance for the HER at large current densities. Specifically, PtQDs@NiFe LDH delivers 500 and 2000 mA·cm-2 with remarkably low overpotentials of 92 and 252 mV, respectively, markedly outperforming commercial Pt/C (η500 = 190 mV, η2000 = 436 mV). Moreover, when employing NiFe LDH precursor and the prepared PtQDs@NiFe LDH catalyst as the anode and cathode, respectively, in an overall water electrolysis system, only 1.66 V and 2.02 V are required to achieve 500 and 2000 mA·cm-2, respectively, while maintaining robust stability for 200 h. This study introduces a feasible approach for developing HER electrocatalysts to achieve industrial-scale current densities.
Keywords
INTRODUCTION
The primary source of energy consumption remains to be fossil fuels[1-3]. However, the widespread consumption of fossil fuels during industrialization not only triggers an energy crisis but also leads to a series of global issues, such as extreme weather, environmental pollution, and global temperature rise[4-8]. To achieve sustainable development of human society, numerous researchers are urgently seeking zero-carbon, easily accessible green energy sources to replace traditional energy in the foreseeable future[9]. Hydrogen (H2) has attracted considerable interest as a clean fuel owing to its impressive calorific value of 142 MJ/kg and its crucial role as an industrial raw material, including ammonia synthesis, methanol synthesis, and metal smelting[10-14]. Among the various methods for H2 generation, electrochemical water splitting technology offers an ideal means of converting the unstable electricity provided by intermittent energy sources such as wind and tidal energy into high-purity H2[15-17]. Unfortunately, the electrochemical water splitting involves a two-electron transfer process at the cathode (hydrogen evolution reaction, HER) and a four-electron transfer process at the anode (oxygen evolution reaction, OER), which results in significant kinetic barriers[18-20]. Therefore, it is imperative to research and develop inexpensive and efficient electrocatalysts to enhance both HER and OER.
Based on this situation, tremendous efforts have been dedicated to the research of HER electrocatalysts, resulting in major progress in recent years. Among the various materials, transition metal (TM)-based electrocatalysts, including TM-oxides, TM-hydroxides, TM-alloys, TM-nitrides, and TM-sulfides, have been extensively reported[21-26]. Among them, researchers have demonstrated significant interest in TM layered double hydroxides (TM-LDHs) owing to their exceptional two-dimensional layered structure, which endows them with distinctive electronic structures, tunable chemical compositions, and large specific surface areas[27-29]. The NiFe LDH, as one of the TM-LDH electrocatalysts, has gained widespread recognition for its extensive application potential due to its abundant raw materials, cost-effectiveness, and exceptional catalytic performance in the OER process[30,31]. However, the affinity for NiFe LDH with H is relatively weak, resulting in a poor ability to cleave the H-O-H bond, which leads to a high energy barrier for HER in alkaline media[32,33]. Furthermore, the inadequate conductivity of NiFe LDH and the restricted active sites also adversely affect its HER performance[34,35]. Therefore, it is crucial to adopt effective strategies to bolster the intrinsic activity of NiFe LDH and optimize the adsorption/desorption of H intermediates to improve the HER catalytic performance. For instance, Chen et al.[32] achieved successful substitution of some Fe atoms in NiFe LDH with Ru atoms (NiFeRu LDH) using a one-pot hydrothermal method to create an efficient difunctional electrocatalyst. The NiFeRu LDH electrocatalyst requires overpotentials of 29 mV (for HER) and 225 mV (for OER) to achieve 10 mA·cm-2 in 1 M KOH. The experimental and theoretical calculations demonstrate that the introduction of Ru atoms can lower the energy barrier, and effectively accelerate the HER reaction kinetics. Although the HER performance of non-precious metal-based electrocatalysts has been greatly improved, it still lags behind that of precious metal-based electrocatalysts[36-39]. Unfortunately, the high cost, scarcity, and poor stability of precious metals pose significant barriers to their large-scale industrial applications[40,41]. Practical experience has proven that the electrocatalytic performance can be significantly improved and costs can be reduced by reducing the usage of precious metals, decreasing their size, and combining them with non-precious metals[42]. For example, Lei et al.[10] prepared Pt quantum dot (PtQDs) coupled S-doped NiFe LDH HER electrocatalysts (Pt@S-NiFe LDHs) with a Pt loading content of only 4.68% using hydrothermal and electrodeposition methods. Pt@S-NiFe LDHs exhibit excellent HER performance due to the optimized binding energy (BE), rapid mass transport, and gas release. However, there is room for improvement in enhancing its catalytic activity and stability at ampere-level current density.
In this work, we successfully dispersed PtQDs on the NiFe LDH nanosheet surface (PtQDs@NiFe LDH) using a two-step simple chemical etching method. The characterization results indicate that the strong electronic interactions between the PtQDs and NiFe LDH in PtQDs@NiFe LDH, which adjusts the electronic structure and accelerates the HER reaction kinetics, ultimately leading to excellent HER performance at high current densities (> 500 mA·cm-²). Specifically, the PtQDs@NiFe LDH electrocatalyst only needs the overpotentials of 53 and 140 mV to realize 100 and 1000 mA·cm-2, respectively. In addition, the PtQDs@NiFe LDH electrocatalyst can deliver 2000 mA·cm-² with a low overpotential of 252 mV. Furthermore, a two-electrode cell was constructed with PtQDs@NiFe LDH serving as the cathode and NiFe LDH acting as the anode [PtQDs@NiFe LDH (-) || NiFe LDH (+)], achieving 100 and 1000 mA·cm-2 of mere potentials of 1.54 and 1.75 V, respectively. This research offers valuable insights for the advancement of affordable and efficient electrocatalysts.
MATERIALS AND METHODS
Preparation of NiFe LDH
In detail, 2.02 g of Fe(NO3)3∙9H2O was dissolved in 50 mL of deionized (DI) water and sonicated for 5 min to form a homogeneous solution. A clean nickel foam (NF) substrate (2 × 3 cm2) was then immersed in the mixture and reacted at room temperature (25 ℃) for 8.5 h. Upon completion of the reaction, the sample was rinsed several times with DI water and anhydrous ethanol, and then dried in an oven at 50 ℃ for 12 h to obtain the NiFe LDH-8.5 (abbreviated as PtQDs@NiFe LDH) precursor. To obtain the optimal sample, additional samples were prepared with reaction times of 6.5 and 10.5 h, respectively, and named NiFe LDH-6.5 and NiFe LDH-10.5, respectively.
Preparation of PtQDs@NiFe LDH
The synthesis of PtQDs@NiFe LDH was also achieved through a chemical etching method. Firstly, 20 mg H2PtCl6∙6H2O was added to 4 mL DI water and 6 mL anhydrous ethanol, and the mixture was sonicated for 10 min to form a homogeneous solution. Secondly, the NiFe LDH (2 × 3 cm2) was completely immersed in the mixture and reacted at room temperature (25 ℃) for 3 h. Finally, upon completion of the reaction, the sample was rinsed several times with DI water and anhydrous ethanol, and then dried in an oven at 50 ℃ for 12 h to obtain PtQDs@NiFe LDH-3 (abbreviated as PtQDs@NiFe LDH). The mass loading of Pt species on the NiFe LDH was determined to be 1.4 mg·cm-2 by weighing the sample before and after the reaction. To obtain the optimal sample, additional samples were prepared with reaction times of 1 and 5 h, respectively, and named PtQDs@NiFe LDH-1 and PtQDs@NiFe LDH-5, respectively. The mass loadings of Pt species of PtQDs@NiFe LDH-1 and PtQDs@NiFe LDH-5 were measured as 0.3 mg·cm-2 and 2.1 mg·cm-2, respectively.
RESULTS AND DISCUSSION
Characterization results
The self-supported PtQDs@NiFe LDH was obtained through a two-step feasible chemical etching method. As shown in Figure 1A, NF was first immersed in Fe(NO3)3∙9H2O solution and reacted for 8.5 h to synthesize the NiFe LDH precursor. Then, the NiFe LDH precursor was placed in H2PtCl6∙6H2O solution for 3 h to synthesize the PtQDs@NiFe LDH electrocatalyst. In this process, Pt4+ is reduced to Pt0 due to the electrode potential difference between
Figure 1. The structure and morphology of PtQDs@NiFe LDH. (A) The schematic synthesis route. (B, C) SEM and TEM images of PtQDs@NiFe LDH. (D) XRD patterns of PtQDs@NiFe LDH and NiFe LDH. (E, F) HRTEM images of PtQDs@NiFe LDH (the PtQDs are marked with pink circles). (G) The size distribution of PtQDs. (H-L) EDS images of PtQDs@NiFe LDH.
The surface electronic structure and chemical states of obtained samples were revealed through X-ray photoelectron spectroscopy (XPS). Figure 2A reveals that the Ni, Fe, and O elements are present in NiFe LDH precursor, while the Ni, Fe, O, and Pt elements are present in PtQDs@NiFe LDH. This aligns with the EDS result of PtQDs@NiFe LDH, further indicating that Pt has been successfully introduced into NiFe LDH. For NiFe LDH, the characteristic peaks located at 855.34 and 872.96 eV are assigned to 2p3/2 and 2p1/2 of Ni2+, respectively, accompanied by two satellite peaks, while the peak at 852.19 eV corresponds to Ni0 [Figure 2B][24,44-46]. The peaks at 711.24 and 724.27 eV are assigned to Fe3+ 2p3/2 and 2p1/2, respectively, accompanied by two satellite peaks [Figure 2C][5,43]. Compared to NiFe LDH, the BEs of Ni 2p and Fe 2p in PtQDs@NiFe LDH are shifted positively by approximately 0.33 and 0.34 eV, respectively, indicating that the coupling between PtQDs and NiFe LDH induces strong electronic interactions in PtQDs@NiFe LDH. For Pt 4f XPS spectra of PtQDs@NiFe LDH [Figure 2D], it can be observed that the peaks at 71.21 and 74.46 eV are attributed to Pt0 4f7/2 and 4f5/2, respectively[47]. Meanwhile, the peaks at 72.50 and 76.32 eV are assigned to Pt2+ 4f7/2 and 4f5/2, respectively[10,48]. This indicates that the predominant form of Pt is metallic Pt, which confirms the successful preparation of PtQDs.
Figure 2. The surface electronic structure and contact angles of the synthesized samples. (A) XPS survey spectra. The XPS spectra of (B) Ni 2p, (C)Fe 2p, (D) Pt 4f and (E) O 1s. (F) EPR spectra. (G-H) TDOS of NiFe LDH without Ov, NiFe LDH with Ov, PtQDs@NiFe LDH without Ov and PtQDs@NiFe LDH with Ov. (K-M) The contact angles. (N, O) The bubble contact angles.
In addition, Figure 2E shows that the O 1s XPS spectra of NiFe LDH are fitted into four peaks, identified as lattice oxygen (M-O, 529.51 eV), hydroxyl oxygen (M-OH, 531.01 eV), oxygen vacancies (Ov, 532.17 eV), and adsorbed H2O (533.32 eV)[35,49]. Notably, there is a positive shift of approximately 0.27 eV in the BE of the O 1s in PtQDs@NiFe LDH compared to NiFe LDH. This serves as additional evidence that the interaction between PtQDs and NiFe LDH in PtQDs@NiFe LDH leads to strong electronic interactions, potentially optimizing the electronic structure. Moreover, the presence of Ov in PtQDs@NiFe LDH and NiFe LDH was further confirmed by electron paramagnetic resonance (EPR). Figure 2F shows a distinct signal of g = 2.003, which corresponds to Ov[50]. The intensity observed in PtQDs@NiFe LDH is significantly higher than that in comparison to NiFe LDH. This indicates the presence of a more abundant amount of Ov in PtQDs@NiFe LDH. To gain a deeper understanding of the impacts of Ov on PtQDs@NiFe LDH electrocatalyst, density functional theory (DFT) was employed. The calculated models include NiFe LDH without Ov, NiFe LDH with Ov, PtQDs@NiFe LDH without Ov, and PtQDs@NiFe LDH with Ov [Supplementary Figure 5]. The formation energies of Ov in NiFe LDH and PtQDs@NiFe LDH are calculated to be -0.024 and -0.259 eV, respectively, indicating that the formation of Ov in both NiFe LDH and PtQDs@NiFe LDH is thermodynamically spontaneous, and the introduction of PtQDs promotes the formation of Ov. This finding aligns with the results of XPS and EPR, reconfirming that PtQDs@NiFe LDH contains a higher concentration of Ov. The increased concentration of Ov in PtQDs@NiFe LDH serves to optimize the H adsorption/desorption process and promote water dissociation, thereby improving the kinetics of HER[51,52]. Furthermore, the electronic structure of PtQDs@NiFe LDH was analyzed by calculating the total density of states (TDOS) to assess the effects of Ov formation and PtQDs introduction. Figure 2G-J indicates that after the formation of Ov, the conduction band crosses the Fermi level (EF), suggesting that the formation of Ov can effectively enhance conductivity. Additionally, the introduction of PtQDs significantly reduces the bandgap and increases the intensity of TDOS near EF, indicating that the incorporation of PtQDs also enhances conductivity. These results collectively demonstrate that PtQDs@NiFe LDH possesses superior conductivity, thereby promoting efficient charge transfer and facilitating the HER[53,54]. In addition, the adsorption capability of PtQDs@NiFe LDH for H intermediates was revealed through surface valence band photoemission spectroscopy. In Supplementary Figure 6, the d-band centers of NiFe LDH and PtQDs@NiFe LDH are -5.85 eV and -5.08 eV, respectively. This not only indicates that the introduction of Pt adjusts the d-band center of PtQDs@NiFe LDH to be more proximate to the EF, but also elucidates that PtQDs@NiFe LDH has a stronger adsorption capability for H intermediates, which is likely to be beneficial for enhancing the HER performance of PtQDs@NiFe LDH[45,55].
The surface properties of PtQDs@NiFe LDH and NF were further evaluated by measuring the contact angles and bubble contact angles of PtQDs@NiFe LDH and NF. Figure 2K and Supplementary Figure 7A show that the contact angle of NF is greater than 110° from the initial stage to 1.5 s, indicating its hydrophobic nature. The contact angle of NiFe LDH decreases from 98° at initial stage to 29° at 1.5 s, indicating its hydrophilic nature [Figure 2L and Supplementary Figure 7B]. In contrast to NF and NiFe LDH, the contact angle of PtQDs@NiFe LDH remains 0° from the initial stage to 1.5 s, demonstrating its superhydrophilicity, which can facilitate the intimate contact between PtQDs@NiFe LDH and the solution, thereby contributing to the enhancement of HER performance [Figure 2M and Supplementary Figure 7C][56]. In addition, the bubble contact angles were also measured to assess electrocatalytic performance. Figure 2N and 2O indicates that the bubble contact angles of PtQDs@NiFe LDH and NF are 149° and 128°, respectively. This demonstrates that PtQDs@NiFe LDH exhibits superaerophobicity, which ensures the rapid detachment of H2 bubbles from the surface of PtQDs@NiFe LDH during the HER process, thereby accelerating reaction kinetics. The superhydrophilic and superaerophobic properties of PtQDs@NiFe LDH suggest that it possesses fast mass/charge transfer, which will enhance the HER reaction kinetics[10,36].
HER performance
The HER performance of the samples was assessed in 1 M KOH solution. First, the linear sweep voltammetry (LSV) curves indicate that the HER activity of NiFe LDH is significantly superior to that of NiFe LDH-6.5 and NiFe LDH-10.5 [Supplementary Figure 8]. Supplementary Figure 9 indicates that the HER activity of PtQDs@NiFe LDH is significantly superior to that of PtQDs@NiFe LDH-1 and PtQDs@NiFe LDH-5. Moreover, PtQDs@NiFe LDH also exhibits superior HER performance compared to NiFe LDH, Pt/C, and NF [Figure 3A, B]. Specifically, PtQDs@NiFe LDH only requires 53, 140, and 252 mV of overpotentials to 100, 1000, and 2000 mA·cm-2, respectively, which is far lower than NiFe LDH (η100 = 336 mV, η1000 = 515 mV, and η2000 = 676 mV), Pt/C (η100 = 67 mV, η1000 = 280 mV, and η2000 = 436 mV), and NF (η100 = 284 mV, η1000 = 474 mV, and η2000 = 641 mV). Furthermore, the reaction kinetics of synthesized samples were further evaluated using Tafel slopes. Supplementary Figure 10 illustrates that the Tafel slope of PtQDs@NiFe LDH is 35 mV dec-1, which is notably lower than other control samples. This indicates that PtQDs@NiFe LDH exhibits the most rapid reaction kinetics compared to the other samples and the rate-determining step in the HER process might be the electrochemical desorption (H* + H2O + e- → H2 + OH- + *)[37]. Furthermore, the intrinsic activity of the synthesized samples is assessed through the exchange current density (j0). Figure 3C and Supplementary Table 2 show that PtQDs@NiFe LDH has the highest j0 of 4.325 mA·cm-2 compared to other control samples, indicating its excellent HER activity. Additionally, the Δη/Δlog|j| within different ranges of current densities can be used to evaluate the mass transfer capability of electrocatalysts[42]. The variation of Δη/Δlog|j| for PtQDs@NiFe LDH under different current densities is more gradual compared to Pt/C, especially at high current densities, indicating that PtQDs@NiFe LDH possesses superior HER activity [Figure 3D]. Additionally, the charge transfer rates of the prepared samples were evaluated using electrochemical impedance spectroscopy (EIS), and the equivalent circuit diagram is shown in Supplementary Figure 11. Figure 3E shows that PtQDs@NiFe LDH exhibits the smallest semicircle diameter of 1.62 Ω, lower than other samples, indicating its rapid charge transfer kinetics. Additionally, the electrocatalytic activity of PtQDs@NiFe LDH and other samples was further evaluated by testing the cyclic voltammetry (CV) in the non-Faraday region [Supplementary Figure 12]. Figure 3F shows that the double-layer capacitance (Cdl) of PtQDs@NiFe LDH is 55 mF·cm-2, significantly exceeding the values of other control samples. This reveals the exposure of numerous active sites in PtQDs@NiFe LDH, demonstrating its superior HER activity. Moreover, Figure 3G shows that PtQDs@NiFe LDH can operate stably for 55 h at 500 and 1000 mA·cm-2, indicating its excellent durability. Notably, PtQDs@NiFe LDH exhibits superior catalytic performance and rapid reaction kinetics at high current densities, surpassing most previously reported works [Figure 3H and Supplementary Table 3]. Furthermore, the catalytic activity of PtQDs@NiFe LDH at the temperature (65 ℃) of industrial electrolysis water was evaluated. As shown in Supplementary Figure 13, at 65 ℃, PtQDs@NiFe LDH does not exhibit significant decay and still demonstrates excellent HER activity and the potential for industrial applications. In addition, the acidic HER performance of prepared samples was tested in a three-electrode system in 0.5 M H2SO4 solution. As shown in Supplementary Figure 14A and 14B, PtQDs@NiFe LDH exhibits superior HER catalytic activity under acidic conditions compared to other comparison samples. Specifically, PtQDs@NiFe LDH only requires overpotentials of 39, 59, and 85 mV to achieve 200, 500, and 800 mA·cm-2, respectively. Furthermore, PtQDs@NiFe LDH can operate for 45 h at 200 mA·cm-2 with minimal performance degradation [Supplementary Figure 14C]. These results demonstrate that PtQDs@NiFe LDH possesses excellent HER performance and has potential for industrial application.
Figure 3. HER performance tests. (A) LSV curves. (B) The overpotentials at 100, 1000 and 2000 mA·cm-2. (C) j0 of PtQDs@NiFe LDH and other control samples are derived by Tafel plots. (D) Ratios of Δη/Δlog|j| of PtQDs@NiFe LDH and Pt/C at different current density ranges. (E) Nyquist plots. (F) The Cdl. (G) Stability tests at 500 and 1000 mA·cm-2. (H) Comparison of catalytic activity (overpotentials at 1000 mA·cm-2) and HER kinetics (Tafel slopes) of PtQDs@NiFe LDH with other reported electrocatalysts.
Overall water splitting performance
The overall water splitting (OWS) performance of electrocatalysts is an important criterion for evaluating their potential for industrial application. The OER is a critical component of OWS. Therefore, the OER activity of PtQDs@NiFe LDH-1, PtQDs@NiFe LDH, PtQDs@NiFe LDH-5 electrocatalysts, and a NiFe LDH precursor was tested. Figure 4A and 4B indicates that the NiFe LDH precursor exhibits superior OER performance compared to the samples loaded with PtQDs. Specifically, NiFe LDH requires low overpotentials of 318, 360, and 412 mV to realize 500, 1000, and 1500 mA·cm-2, respectively, outperforming other compared samples. Furthermore, a two-electrode system was constructed using PtQDs@NiFe LDH with excellent HER performance as the cathode electrode and NiFe LDH with superior OER activity as the anode electrode to evaluate the OWS performance [PtQDs@NiFe LDH (-) || NiFe LDH (+)]. For better comparison, another two-electrode system was assembled using Pt/C and RuO2 as the cathode and anode electrodes, respectively, and named Pt/C (-) || RuO2 (+). Figure 4C and 4D demonstrates that the PtQDs@NiFe LDH (-) || NiFe LDH (+) achieves superior water electrolysis performance at high current densities, significantly surpassing the Pt/C (-) || RuO2 (+). Specifically, the PtQDs@NiFe LDH (-) || NiFe LDH (+) electrolyzer only requires 1.54, 1.75, and 2.02 V of the driving voltages to achieve 100, 1000, and 2000 mA·cm-2, respectively, which is notably superior to the commercial Pt/C (-) || RuO2 (+) electrolyzer, indicating that PtQDs@NiFe LDH (-) || NiFe LDH (+) has excellent OWS activity. Furthermore, the PtQDs@NiFe LDH (-) || NiFe LDH (+) electrolyzer can operate stably at 100 mA·cm-2 for 200 h, demonstrating outstanding durability [Figure 4E]. In addition, the Faraday efficiency (FE) of PtQDs@NiFe LDH (-) || NiFe LDH (+) was tested by the drainage method [Figure 4F]. Figure 4G shows that the measured ratio of H2 to O2 is 2 : 1, and the calculated FE is close to 100%, indicating its excellent catalytic activity. Additionally, the OWS performance of the PtQDs@NiFe LDH (-) || NiFe LDH (+) electrolyzer outperforms the majority of catalysts reported in previous studies [Figure 4H and Supplementary Table 4]. These results suggest that PtQDs@NiFe LDH (-) || NiFe LDH (+) has significant potential for industrial applications.
Figure 4. The OWS performance tests. (A) LSV curves of NiFe LDH, PtQDs@NiFe LDH-1, PtQDs@NiFe LDH, and PtQDs@NiFe LDH-5. (B) The overpotentials at 500, 1000 and 1500 mA·cm-2. (C) LSV curves of PtQDs@NiFe LDH (-) || NiFe LDH (+) and Pt/C (-) || RuO2. (D) The cell voltages at different current densities. (E) Stability tests. (F) Photographs of gas collection at different times. (G) Theoretical and measured gas production at different times. (H) Comparison of the driving voltage of PtQDs@NiFe LDH (-) || NiFe LDH (+) with other reported electrocatalysts.
CONCLUSIONS
In summary, a self-supported heterogeneous PtQDs@NiFe LDH electrocatalyst for water electrolysis at ampere-level current densities was successfully synthesized by coupling small and well-dispersed PtQDs with NiFe LDH nanosheets. The PtQDs@NiFe LDH exhibits attractive HER catalytic performance in an alkaline electrolyte, which achieves 500 and 1000 mA·cm-2 with low overpotentials of 92 and 140 mV, respectively, substantially lower than that of benchmark Pt/C (η500 = 190 mV, η1000 = 280 mV). In addition, PtQDs@NiFe LDH can operate stably at 500 and 1000 mA·cm-2 for 55 h, indicating its potential for scalable H2 production. A series of materials characterizations indicate that there are strong electronic interactions between PtQDs and NiFe LDH in PtQDs@NiFe LDH, which optimizes the charge distribution and balances the adsorption/desorption of H intermediates on PtQDs@NiFe LDH, thereby enhancing the HER performance. Furthermore, when using the NiFe LDH precursor and the prepared PtQDs@NiFe LDH catalyst as the anode and cathode in an OWS system, which requires only 1.66 V and 2.02 V to reach 500 and 2000 mA·cm-2, respectively, while maintaining robust stability for 200 hours. This study offers a reference for developing affordable and high-performance electrocatalysts for H2 production under large current densities.
DECLARATIONS
Authors’ contributions
Conceptualization, Investigation, Methodology, Data curation, Writing-Original draft: Wang B, Zhao X, Sun H
Conceptualization, Investigation, Software: Zhang M, Qiu G, Li D, Zhang J
Supervision, Project administration, Writing-review & editing: Sun H, Liu Q
Funding acquisition: Chen M, Zhang Y, Sun H, Liu Q
Validation, Software: Wu Y, Liu C, Yang H, Lu Q, Zhou T, Zhao J, Cui H, Liu F
Availability of data and materials
The raw data supporting the findings of this study are available within this Article and its Supplementary Materials. Further data is available from the corresponding authors upon reasonable request.
Financial support and sponsorship
This work was funded by the National Key Research and Development Program of China (2022YFB3803600); the National Natural Science Foundation of China (22368050, 22378346), the Key Research and Development Program of Yunnan Province (202302AF080002); the Yunnan Basic Applied Research Project (202401AT070460, 202401AU070229); the Scientific Research Fund Project of Yunnan Education Department (2024J0014, 2024J0013); and the Open Project of Yunnan Precious Metals Laboratory Co.; Ltd (YPML-2023050259, YPML-2023050260). The authors thank the Shiyanjia Lab (www.shiyanjia.com), the Electron Microscopy Center, and the Advanced Analysis and Measurement Center of Yunnan University for the sample testing and computational services.
Conflicts of interest
Hao Cui and Feng Liu are affiliated with Yunnan Precious Metals Laboratory Co., Ltd.
The other authors declared that there are no conflicts of interest.
Ethical approval and consent to participate
Not applicable.
Consent for publication
Not applicable.
Copyright
© The Author(s) 2025.
Supplementary Materials
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Wang, B.; Zhao, X.; Sun, H.; Zhang, M.; Chen, M.; Qiu, G.; Zhou, T.; Li, D.; Wu, Y.; Liu, C.; Yang, H.; Lu, Q.; Zhao, J.; Zhang, Y.; Zhang, J.; Cui, H.; Liu, F.; Liu, Q. Pt quantum dots coupled with NiFe LDH nanosheets for efficient hydrogen evolution reaction at industrial current densities. Microstructures 2025, 5, 2025024. http://dx.doi.org/10.20517/microstructures.2024.76
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