Ultra-low Voltage Research Articles

Fortifying Zinc Metal Anodes against Uncontrollable Side‐Reactions and Dendrite Growth for Practical Aqueous Zinc Ion Batteries: A Novel Composition of Anti‐Corrosive and Zn2+ Regulating Artificial Protective Layer

AbstractAqueous zinc‐ion batteries (AZIBs) have recently gained significant attention for grid‐scale energy storage applications owing to their high intrinsic energy density, low cost, and environmental benignity. Nevertheless, uncontrolled Zn dendrite accumulation, H2 gas generation, and inevitable corrosion resulting from intricate water‐induced side‐reactions remain the main hurdles to AZIB commercialization. To overcome these problems, it is imperative to develop easy‐to‐handle strategies for the construction of versatile artificial protective layers (APL) on Zn surfaces. Inspired by the suppressed HER and anti‐corrosive properties of zinc silicate (Zn2SiO4), this study rationally designed a novel APL consisting of Zn2SiO4 nanospheres and decorated surface‐modified carbon nanotube (CNT) to produce a stable and durable Zn anode (C‐ZSL@Zn). The C‐ZSL layer simultaneously improved Zn2+ transport kinetics and the Zn2+ de‐solvation effect, maintained electrically insulating properties, and uniformized Zn2+ flux on the Zn surface, synergistically enabling corrosion‐free and dendrite‐free Zn plating/stripping behavior on C‐ZSL@Zn. Consequently, the C‐ZSL@Zn achieved prolonged lifespans of ≈1600 (at 1 mA cm–2) and ≈1100 h (at a high depth of discharge of ≈51.24%) with ultralow voltage hysteresis in symmetric cells, together with improved cycling stability for coin‐ and pouch‐type Zn||α‐MnO2 full‐cells. This study creates a new avenue for constructing stable APL@Zn anodes for practical applications.

Design and analysis of hybrid 10T adder for low power applications

Recently, a growing focus has been on the need for ultra-low-voltage (ULV) functioning to reduce energy usage. The full adder is a fundamental computational arithmetic unit in various image and signal processing applications. This study presents a novel architectural design for a 1-bit adder that utilizes 10 transistors. The concept relies on an energy-efficient hybrid logic multiplexer approach incorporating Gate Diffusion Input (GDI) logic. The primary goal of the suggested design for a hybrid full adder is to decrease power consumption while concurrently decreasing the required area. The suggested innovative architectural design for a full adder incorporates level restoration carry logic and ensures a complete swing output voltage. The designs have been analyzed in a standard environment using 45-nm CMOS process technology, with various supply voltages utilized. The evaluation of the adder cells focuses on speed, power consumption, power-delay-product (PDP), and space efficiency compared to the existing full adders. The recommended full adder cells were subjected to comprehensive simulation tests utilizing the Mentor Graphics environment. The results suggest that these cells surpass their counterparts, exhibiting a minimum of 80 % enhancements in their power-delay product (PDP) parameters. Also the comparisons have been made between the proposed full adders with and without level restoration techniques. The proposed level restoration technique based full adder yields better performance in terms of power and delay when compared to proposed full adder without level restoration.

Recycled Tandem Catalysts Promising Ultralow Overpotential Li-CO2 Batteries.

Lithium-carbon dioxide (Li-CO2 ) batteries are regarded as a prospective technology to relieve the pressure of greenhouse emissions but are confronted with sluggish CO2 redox kinetics and low energy efficiency. Developing highly efficient and low-cost catalysts to boost bidirectional activities is craved but remains a huge challenge. Herein, derived from the spent lithium-ion batteries, a tandem catalyst is subtly synthesized and significantly accelerates the CO2 reduction and evolution reactions (CO2 RR and CO2 ER) kinetics with an in-built electric field (BEF). Combining with the theoretical calculations and advanced characterization techniques, this work reveals that the designed interface-induced BEF regulates the adsorption/decomposition of the intermediates during CO2 RR and CO2 ER, endowing the recycled tandem catalyst with excellent bidirectional activities. As a result, the spent electronics-derived tandem catalyst exhibits remarkable bidirectional catalytic performance, such as an ultralow voltage gap of 0.26V and an ultrahigh energy efficiency of 92.4%. Profoundly, this work affords new opportunities to fabricate low-cost electrocatalysts from recycled spent electronics and inspires fresh perceptions of interfacial regulation including but not limited to BEF to engineer better Li-CO2 batteries.

Ultra-low turn-on voltage (0.37 V) vertical GaN-on-GaN Schottky barrier diode via oxygen plasma treatment

In this work, vertical gallium nitride (GaN) Schottky barrier diodes (SBDs) with an ultra-low turn-on voltage VON (0.37 V) were demonstrated. Due to the process of O2 plasma treatment, GaON was formed on the surface of GaN and further modified the surface potential of the material surface, which made the VON decrease from 0.62 to 0.37 V. Spin-on-glass was deposited on top of devices to form the floating guard ring, which was used to improve the breakdown voltage to 681 V (at J = 1 A/cm2) by reducing the electric field distribution. The vertical GaN SBDs exhibit a specific on-resistance (RON) of 2.6 mΩ cm2. Deterioration of the device under different stress time changes slightly showed great stability of the devices.

Field-Assisted Regulation Induced by Cobalt-Doped ZnO for Dendrite-Free Lithium Metal Anodes.

Lithium metal batteries are deemed as an optimal candidate for the next generation of durable energy storage devices. However, the growth of lithium dendrite and significant volume expansion pose as obstacles that impede the application of lithium metal batteries. In this work, a functional copper current collector was designed by coating it with Co-doped ZnO (Co/ZnO) to enhance the lithiophilicity through local electric fields and built-in magnetic fields induced by the ferromagnetic material. The incorporation of Co not only induces a local electric field and thus accelerating electron transfer, but also imparts the ferromagnetic behavior to ZnO, resulting in an internal magnetic field to regulate the dynamic trajectory. Profiting from the above advantages, the symmetric cells have excellent cycle stability in 1 mA cm-2 and 1 mAh cm-2 , maintaining ultra-low voltage for over 2000 h. This study provides a realizable pathway for next-generation current collector of copper modification.

High-performance electroionic artificial muscles boosted by superior ion transport with Ti3C2Tx MXene/Cellulose nanocomposites for advanced 3D-motion actuation

Low-voltage driven electro-ionic soft actuators with large deformation strain are of promising candidate for high-performance artificial muscles, with practical applications in flexible electronics, biomedical assistive devices and soft robotics. However, enhancing the actuation response and long-term stability along with excellent bending properties simultaneously still remain significant challenges. Herein, an elaborate ionically crosslinked nanocomposite membrane, assembled with 1D bacterial cellulous (BC) nanofibers and 2D Ti3C2Tx MXene nanomaterials, is reported to improve constrained ion transport for high-performance electrically activated ionic actuator. The 3D interpenetrating frameworks, arising from the synergistic effects of such combination, not only serve to enhance ion selectivity through the presence of intrinsically negatively charged functional groups but also expand the initially confined pathways, thus diminishing the energy barrier to ion transport. As a result, the integrated superior functionalities of the soft actuator exhibit large bending strain of 0.88 % with the tip displacement of 10.8 mm, ultra-stable cycling performance (>99 % retention for 5 h), and ultrabroad material response range up to 18 Hz under an ultralow voltage exertion of 0.5 V. Furthermore, the demonstration of the prototype soft actuators as actuating tracking beams of 3D-adaptive motion platform for plate deformable mirror shows their potential applications of soft robotics, thereby offering a dependable solution for driving the next generation of sophisticated intelligent systems.

Crystalline Ni5P4/amorphous CePO4 core/shell heterostructure arrays for highly-efficient electrocatalytic overall water splitting

Exploring low-cost and highly efficient bifunctional electrocatalysts for overall water splitting has become a research focus recently. Crystalline/amorphous core/shell heterostructures have great potential for applications in the field of electrocatalytic overall water splitting. However, related research is still challenging. Herein, crystalline Ni5P4 nanosheets/amorphous CePO4 nanocrystals core/shell heterostructure arrays were developed for electrocatalytic overall water splitting. It is shown that the heterostructure array required competitive HER and OER overpotentials of 94 and 191 mV in alkaline environment (10 mA/cm2), respectively. Encouragingly, the symmetrical two-electrode system constructed with the heterostructure array only required an ultra-low cell voltage of 1.535 V to achieve a current density of 10 mA/cm2. This indicates the system has huge potential in overall water splitting. The electrocatalytic mechanism was studied systematically by combining theoretical calculation and experimental characterization. It was found that the surface coating of amorphous CePO4 could not only significantly increase the electrochemical active surface area and improve the charge transfer of crystalline Ni5P4 nanosheets, but could also regulate d-band center of Ni5P4 and optimize the adsorption towards reaction intermediates in water splitting. The results not only provide an excellent crystalline/amorphous core/shell heterostructure bifunctional electrocatalyst for overall water splitting but also greatly expand the application of rare earth metal phosphate CePO4.

Iron-doped cobalt nitride as an efficient electrocatalyst towards energy saving hydrazine assisted seawater splitting in near neutral to highly alkaline pH achieving industry level current density

Replacing sluggish anodic oxygen evolution reaction by hydrazine oxidation reaction in seawater electrolysis is one of the smartest ways of getting multiple benefits as it offers an energy saving route for hydrogen production keeping the cell voltage way smaller than responsible voltage for corrosive chloride oxidation. Here, we report iron-doped Co3N as highly active electrocatalyst towards hydrazine oxidation reaction and hydrogen evolution reaction in wide pH range of 7–14. The two-electrode electrolyser system reached industry scale current density of 1000 mA cm−2 at ultralow cell voltage of 0.65 V, and found sustainable at 500 mA cm−2 over 95 h in hydrazine assisted alkaline seawater splitting. The electrolyser system also achieved 200 mA cm−2 current density at 0.75 V in hydrazine assisted neutral seawater medium. Interestingly, a thin amorphous iron oxide layer formed in Fe-doped Co3N provided much needed protection during electrocatalysis offering long term stability at industry level current density.

Lowering Sodium‐Storage Lattice Strains of Layered Oxide Cathodes by Pushing Charge Transfer on Anions

Due to a high energy density, layered transition‐metal oxides have gained much attention as the promising sodium‐ion batteries cathodes. However, they readily suffer from multiple phase transitions during the Na extraction process, resulting in large lattice strains which are the origin of cycled‐structure degradations. Here, we demonstrate that the Na‐storage lattice strains of layered oxides can be reduced by pushing charge transfer on anions (O2−). Specifically, the designed O3‐type Ru‐based model compound, which shows an increased charge transfer on anions, displays retarded O3–P3–O1 multiple phase transitions and obviously reduced lattice strains upon cycling as directly revealed by a combination of ex situ X‐ray absorption spectroscopy, in situ X‐ray diffraction and geometric phase analysis. Meanwhile, the stable Na‐storage lattice structure leads to a superior cycling stability with an excellent capacity retention of 84% and ultralow voltage decay of 0.2 mV/cycle after 300 cycles. More broadly, our work highlights an intrinsically structure‐regulation strategy to enable a stable cycling structure of layered oxides meanwhile increasing the materials' redox activity and Na‐diffusion kinetics.

Hierarchical electronic coupling engineering of bimetallic sulfide driven by CoFe bimetal MOFs anchored on MXene promotes efficient overall water splitting

Rational design cost-effective water-splitting catalysts are essential for current energy storage and conversion. Here, we ingeniously design alloy-phase bimetallic sulfides anchored on the conductive substrate MXene, obtained by a facile topological hydrothermal sulfide method of self-template sacrifice using bimetallic MOFs. Density functional theory calculations (DFT) and related material characterization demonstrate that electron rearrangement at the atomic/orbital level and hierarchical electronic coupling between Schottky heterostructures of MXene boosts charge transfer efficiency, the asymmetric 3d electronic structure of the Co-Fe atoms optimizes the d-band center value εd of the Co8FeS8 MXene/NF. Thus, the efficient composite electrocatalyst of Co8FeS8 MXene/NF with multi-metal active sites exhibits extraordinary electrocatalytic performance with remarkably low overpotentials of 171 mV (OER) and 108 mV (HER) at 10 mA cm−2, respectively. Notably, when used in 1 M KOH electrolytic cell, Co8FeS8 MXene/NF also accelerate overall water splitting at an ultra-low cell voltage of only 1.51 V at 10 mA cm−2, far exceeding that of standard Pt-C/NF//RuO2/NF electrodes (1.59 V). This work gives an effective strategy to construct MOF-derived alloy-phase bimetallic sulfides and improve the intrinsic activity of alloy-phase bimetallic sulfides electrochemical catalysts.

Interfacial electronic engineering of heterostructured Co2P-MoNiP/NF nano-sea-urchin catalysts for efficient and stable hydrogen evolution via water/seawater splitting

Using hydrogen as a fuel is an effective way to combat the energy crisis, at the same time, reduce greenhouse gas emissions. Designing high-performance and low-cost catalysts for the hydrogen evolution reaction (HER) is critical for commercial seawater electrolysis. Here, we designed a heterostructured Co2P-MoNiP/NF nano-sea-urchin catalyst that only showed an overpotential of 46 mV for 10 mA cm−2 to actuate HER in alkaline electrolytes along with superior stability. Theoretical calculations demonstrate that the constructed heterogeneous interfaces effectively promote the redistribution of the charge density and optimize the adsorbed hydrogen intermediates, lowering the hydrogen adsorption free energy barrier and promoting H2 desorption, thus boosting the HER activity. Moreover, the assembled two-electrode electrolyzer only required ultra-low voltages of 1.51 and 1.66 V to deliver current densities of 10 and 100 mA cm−2, respectively. The solar-driven water electrolysis system achieves a high and stable solar-to-hydrogen (STH) conversion efficiency of 19.68 %.

Improved oxygen ion migration efficiency and resistive switching properties in SrFeOx memristor with vertical superlattice-like structure

The resistive switching (RS) behaviour between high and low resistance states in SrFeOx memristors originates from topological phase transition (TPT) induced by the migration of oxygen ions. Accelerating the migration of oxygen ions in the anisotropic crystal structure of SrFeO2.5 is of great importance for improving the RS properties and promoting the application for this TPT memristor. In this study, SrFeOx TPT memristors with different superlattice-like (SLL) structures were fabricated and the prepared devices with a vertical-type SIL structure display an ultra-low operation voltage of only 0.6 V, excellent cycling stability, data retention, and endurance performance. Moreover, the microstructures of vertical and horizontal SLL SrFeO2.5 were characterized with X-ray diffraction and transmission electron microscope. Furthermore, the differences in oxygen ion migration rate in the two structures were also tested by in-situ X-ray photoelectron spectroscopy. Finally, the optical band gaps and oxygen ion migration barriers of the two structures were calculated using first principles. All the characterizations and simulation results prove that the vertical type SrFeOx shows a higher oxygen ion migration efficiency. More encouragingly, the vertical SLL devices exhibit up to 96 % recognition accuracy for the Mixed National Institute of Standards and Technology image recognition task.

Metal Clusters Effectively Adjust the Local Environment of Polymeric Carbon Nitride for Bifunctional Overall Water Splitting.

Compared with single-atom catalysts, clusters not only possess more metal-loadings and stability but also provide flexible active sites to break the linear scaling relationship of multistep reactions. However, exploring precise structure-activity relationships and the synergistic effect between clusters and nanosheets is still in its infancy. Here, based on first-principles and nonequilibrium Green's function simulation, the C2N-supported Fe and Co tetrahedral clusters exhibit remarkable bifunctional catalytic performance with a very low overpotential of hydrogen (0.12 and 0.07 V) /oxygen (0.20 and 0.55 V) evolution reactions (HER/OER), respectively. The C2N-regulated Fe and Co clusters have suitable d-band centers around the Fermi surface for HER. In turn, the Fe and Co clusters activate the subadjacent dual-carbon sites for OER. Simultaneously, the cluster enhances the electronic conductivity of C2N, and the initial current only needs ultralow bias voltage around 0.1-0.4 V. The desired metal cluster regulation strategy offers cost-effective potential for advancing clean energy technology.

A flexible carbon nanotube film modified with gradient lithiophilic Cu2O/Cu heterojunction for dendrite-free lithium metal anodes

Lithium (Li) metal batteries have been extensively studied for their high energy density, but uncontrolled Li dendrites and severe volume fluctuation significantly limit their commercial applications. To address this issue in Li metal anodes, a flexible self-supporting film was developed by integrating Cu2O/Cu heterojunction with a gradient distribution and a three-dimensional (3D) single-walled carbon nanotube (SWCNT) network. The top-down gradient distribution of Cu2O/Cu effectively reduces the Li+ concentration polarization and conductivity polarization in the vertical direction within the 3D framework, achieving bottom-up deposition of Li inside the framework. Moreover, Mott-Schottky junction between lithiophilic Cu2O and Cu can trigger the built-in electric field (BIEF) at their heterointerfaces, thereby accelerating electron transfer and Li+ migration. Benefiting from the physicochemical bidirectional regulation, the Cu2O/Cu@SWCNT/Li realizes an ultralow voltage polarization of 13 mV and a prolonged cycling stability over 1800 h in a symmetric cell (1 mA cm−2 and 1 mAh cm−2). Additionally, the film shows excellent cycle stability in the Cu2O/Cu@SWCNT-Li//LiFePO4 full cell, providing practical ideas for the subsequent design of lithium metal anodes.

Charge Self-Regulation of Metallic Heterostructure Ni2 P@Co9 S8 for Alkaline Water Electrolysis with Ultralow Overpotential at Large Current Density.

Designing cost-effective alkaline water-splitting electrocatalysts is essential for large-scale hydrogen production. However, nonprecious catalysts face challenges in achieving high activity and durability at a large current density. An effective strategy for designing high-performance electrocatalysts is regulating the active electronic states near the Fermi-level, which can improve the intrinsic activity and increase the number of active sites. As a proof-of-concept, it proposes a one-step self-assembly approach to fabricate a novel metallic heterostructure based on nickel phosphide and cobalt sulfide (Ni2 P@Co9 S8 ) composite. The charge transfer between active Ni sites of Ni2 P and Co─Co bonds of Co9 S8 efficiently enhances the active electronic states of Ni sites, and consequently, Ni2 P@Co9 S8 exhibits remarkably low overpotentials of 188 and 253mV to reach the current density of 100mAcm-2 for the hydrogen evolution reaction and oxygen evolution reaction, respectively. This leads to the Ni2 P@Co9 S8 incorporated water electrolyzer possessing an ultralow cell voltage of 1.66 V@100mAcm-2 with ≈100% retention over 100h, surpassing the commercial Pt/C║RuO2 catalyst (1.9 V@100mAcm-2 ). This work provides a promising methodology to boost the activity of overall water splitting with ultralow overpotentials at large current density by shedding light on the charge self-regulation of metallic heterostructure.

Dealloying-derived TiC hierarchical porous frameworks as stable host for advanced Li metal electrode

Metallic Li has been presented to be an attractive anode for next generation energy storage devices. Nevertheless, uncontrollable Li dendrites growth and great volume change seriously restrict its applicability. Herein, we designed a hierarchical porous TiC as Li host for the advanced Li metal anode through a one-step mild dealloying method. The Li nucleation overpotential was effectively reduced due to the lithiophilic TiC as nucleation sites. Furthermore, the multilayered hierarchical structure could homogenize the current distribution and provide enough space to restrict the volume change during the cycling. As a result, the half-cell assembled with as-dealloyed TiC exhibited a markedly enhanced Coulombic efficiency of 98.5% over 400 cycles at 1 mA cm−2. The TiC/Li electrode cycled for over 1000 h with an ultralow voltage hysteresis of 17.1 mV in a symmetrical cell at 1 mA cm−2 for 1 mAh cm−2, which showed a stable cycle capacity of 117.2 mAh g− 1 at 1 C after 700 cycles in a full cell with a LiFePO4 cathode. This work provided a facile strategy to design stable host and solve the problem with Li metal batteries.

Unveiling the origin of activity in RuCoOx-anchored nitrogen-doped carbon electrocatalyst for high-efficiency hydrogen production and hydrazine oxidation using Raman spectroscopy

Hydrazine-assisted water electrolysis has gained much attention nowadays as an energy-saving strategy for the large-scale production of hydrogen fuel. Regardless, the synthesis of highly proficient bifunctional electrocatalysts remains a major challenge. Metal–organic frameworks (MOF) derived electrocatalysts have recently demonstrated excellent bifunctional activity in water electrolysis. Herein, we developed a new type of Ru-MOF on rod-like Co-MOF (Ru/Co-MOF) microstructures via a two-step solvothermal route. Subsequently, the Ru/Co-MOF was used as a precursor and self-template to synthesize an electrocatalytically active RuO2/Co3O4 anchored nitrogen-doped carbon (RuCoOx@NC) composite via a one-pot pyrolysis–oxidation strategy under atmospheric air. The RuCoOx@NC composite showed an ultralow overpotential of 44 mV for the hydrogen evolution reaction and 255 mV for the oxygen evolution reaction at 10 mA cm−2 in a 1 M KOH solution. Besides, the RuCoOx@NC composite exhibited an ultra-small working potential of − 0.040 V (vs. reversible hydrogen electrode (RHE)) for the hydrazine oxidation reaction at 10 mA cm−2 in a 1 M KOH/0.5 M hydrazine solution. The assembled RuCoOx@NC∥RuCoOx@NC membrane-free overall hydrazine splitting electrolyzer only required ultralow cell voltages of 0.063 and 0.505 V to produce 10 and 100 mA cm−2, with remarkable long-term stability, demonstrating its exceptional bifunctional activity. Ex situ Raman spectroscopy results indicate that both Co3O4 and RuO2 species contribute to the electrocatalytic activity of the RuCoOx@NC composite. This work suggests a potential strategy for developing bifunctional electrocatalytic materials for energy-saving hydrogen production to solve future energy demands.

Energy‐efficient organic photoelectric synaptic transistors with environment‐friendly CuInSe2 quantum dots for broadband neuromorphic computing

AbstractPhotoelectric synaptic device is a promising candidate component in brain‐inspired high‐efficiency neuromorphic computing systems. Implementing neuromorphic computing with broad bandwidth is, however, challenging owing to the difficulty in realizing broadband characteristics with available photoelectric synaptic devices. Herein, taking advantage of the type‐II heterostructure formed between environmentally friendly CuInSe2 quantum dots and organic semiconductor, broadband photoelectric synaptic transistors (BPSTs) that can convert light signals ranging from ultraviolet (UV) to near‐infrared (NIR) into post‐synaptic currents are demonstrated. Essential synaptic functions, such as pair‐pulse facilitation, the modulation of memory level, long‐term potentiation/depression transition, dynamic filtering, and learning‐experience behavior, are well emulated. More significantly, benefitting from broadband responses, information processing functions, including arithmetic computing and pattern recognition can also be simulated in a broadband spectral range from UV to NIR. Furthermore, the BPSTs exhibit obvious synaptic responses even at an ultralow operating voltage of −0.1 mV with an ultralow energy consumption of 75 aJ per event, and show their potential in flexible electronics. This study presents a pathway toward the future construction of brain‐inspired neural networks for high‐bandwidth neuromorphic computing utilizing energy‐efficient broadband photoelectric devices.

A Highly Active and Durable Hierarchical Electrocatalyst for Large-Current-Density Water Splitting.

Designing bifunctional catalysts with high current densities under industrial circumstances is crucial to propelling hydrogen energy with a boost from fundamental to practical application. In this work, heterojunction nanowire arrays consisting of manganese oxide and cobalt phosphide (denoted as MnO-CoP/NF) are designed to meet the industrial demand by regulating the synergic mass transport and electronic structure coupling with numerous nano-heterogeneous interfaces. The optimal MnO-CoP/NF electrode exhibits remarkable bifunctional electrocatalytic performance with overpotentials of 259.5 mV for hydrogen evolution at a large current density of 1000 mA cm-2 and 392.2 mV for oxygen evolution at 1500 mA cm-2. Moreover, the MnO-CoP/NF electrode demonstrates superior durability and an ultralow voltage of 1.76 V at 500 mA cm-2, outperforming that of a commercial RuO2||Pt/C electrode. This work sheds light on the design of metallic heterostructures with optimized interfacial electronic structures and a high abundance of active sites for practical industrial water splitting applications.

Formaldehyde oxidation boosts ultra-low cell voltage industrial current density water electrolysis for dual hydrogen production

The high cost is a major issue that has contributed to the slow industrialization of electrolytic water. To reduce the cell voltage to below 0.5 V, we constructed a hybrid electrolytic water system with coupled hydrogen evolution reaction (HER) and formaldehyde oxidation reaction (FOR). For FOR, the abundant Cu0 and Cu+ in nitrogen-doped Cu/Cu2+1O on Cu foam (N-Cu/Cu2+1O/CF) can effectively promote the adsorption and activation of H2O and HCHO molecules, and facilitate the cleavage of O-H and C-H, while nitrogen doping can promote the exposure of Cu active sites. For HER//FOR, a cell voltage of only 0.42 V is required to achieve 500 mA cm−2. The system can not only produce H2 routinely at the cathode through HER but also release H2 by HCHO oxidation. The construction of a dual hydrogen production system with industrial current density at ultra-low voltage provides a new idea to reduce the cost of hydrogen production.