Remarkable Operational Stability Research Articles

Salt‐Based Catalyzer to Aid Heterogeneous Nucleation Enabling >23% Efficient Electron‐Transport‐Layer‐Free Perovskite Solar Cells

AbstractCharge transport layers are critical components in perovskite solar cells (PSCs) for achieving satisfied power conversion efficiencies (PCEs) and device stability. However, these layers often bring incompatible interfaces and complex fabrication, limiting the stability and scalability of PSC technology. Here an alternative strategy of salt‐based catalyzer (SBC) is proposed to regulate the heterogeneous nucleation of perovskite, which enables uniform and well‐controlled perovskite coverage directly onto the salt‐treated substrate without electron transport layers (ETLs). By carefully adjusting the cations, anions, and the thickness of SBC, high‐quality perovskite films along with superior buried interfaces suppress the carrier recombination losses and strengthen the interfacial stability, promoting the resultant device to achieve a record PCE of 23.04%, which represents the highest reported efficiency for ETL‐free PSCs. Meanwhile, the SBC technique can be well extended to large‐area, flexible, and module‐based devices. More encouragingly, the SBC‐based unencapsulated devices exhibit remarkable operational stability by retaining over 90% of initial efficiency for 1540 h under illumination and for 6312 h in an air environment. This work provides an advisable way to fabricate efficient and stable ETL‐free PSCs toward reliable and cost‐effective production.

Efficient and Highly Stable Lateral Perovskite Single‐Crystal Solar Cells through Crystal Engineering and Weak Ion Migration

AbstractThe lateral device structure for perovskite solar cells (PSCs) has garnered significant attention, primarily due to its elimination of the need for expensive transparent electrodes. However, the performance of lateral devices, which are more sensitive to crystal quality and charge carrier transport bottlenecks, has lagged far behind the predominant vertical PSCs. Herein, by modulating the crystal nucleation and growth processes of thin FA0.75MA0.25PbI3 (FA = formamidinium; and MA = methylammonium) single crystals, crystal quality and carrier transport are improved, resulting in a power conversion efficiency (PCE) of 12.64%, a record for lateral PSCs. Investigation of the device's stability reveals that iodide ion migration is suppressed due to a reduction in the iodide vacancy concentration combined with weak interface iodide ion migration. It is shown that the latter effect is a result of the perpendicular direction of the ion migration and the electric field in the lateral PSCs. Consequently, these lateral single‐crystal PSCs display remarkable operational stability, retaining 100% of their initial PCE after 1200 h of steady‐state output at the maximum power point voltage (Vmpp) under 1 sun illumination. This work highlights the advantages of lateral single‐crystal devices and their potential to address key ion migration issues of PSCs.

Improved performance of Pseudomonas fluorescens lipase immobilized on a magnetic mesoporous solvothermal hybrid-nanocarrier and its application in ultrasonication assisted estolide synthesis

The exponential growth of the biotechnological market necessitates the exploring novel, economically viable materials for enzyme immobilization to enhance the biocatalyst performance. This study involves preparing a hybrid carrier with a magnetic mesoporous nature, using milled rice husk (MRH) and multi-walled carbon nanotubes (MWCNTs) via a one-pot solvothermal process at 200 °C for 6 h. The carrier, rich in-NH2 groups, was chemically bonded to Pseudomonas fluorescens lipase (PFL) using EDC/NHS cross-linkers. The synthesized support achieved a maximum PFL loading of 94.92 mg of protein per gram of support. Moreover, the maximum activity recovery was achieved at 1196 %, under the optimal conditions: immobilization temperature 25℃, pH 9.0, immobilization time 2 h and PFL mass concentration 4 mg/mL. Subsequently, the derived enzyme was used to catalyze ricinoleic acid esterification to synthesize estolide under ultrasound-assisted conditions. The optimized principal parameters for reaction temperature, reaction time, and immobilized lipase loading were respectively determined to be 48.99 °C, 1.60 h, and 3.09 % via response surface methodology. Ricinoleic acid conversion reached 65.23 % under the optimal conditions with the assistance of 40 % power and 40 kHz ultrasonic frequency. Furthermore, remarkable operational stability was also observed, with a retention rate of 49.28 %, even after 10 consecutive batches. This study demonstrates promising prospects for industrial-scale application using ultrasound as a fast and ecologically friendly procedure.

Reverse osmosis membrane with crown ethers decoration for enhanced radionuclides sieving

Reverse osmosis (RO) membranes have been widely applied in the increasingly discharged radioactive wastewater treatment. However, conventional RO membranes suffer from the issues of the limited nuclides rejections and the relatively low water permeance. In this work, a new type of RO membrane with decoration of crown ethers (15C5 and 18C6) was prepared via an interfacial polymerization process to remove the radionuclide-contaminated components. Due to the special hollow structure of crown ethers (CEs) and the hydrogen bonding within the amidogen, the obtained MPD@15C5-TMC and MPD@18C6-TMC membranes exhibited smoother surfaces and thinner polyamide active layers than the pristine MPD-TMC membrane. The optimized MPD@15C5-TMC and MPD@18C6-TMC RO membranes presented excellent pure water permeances up to 2.16 and 2.91 L m−2 h−1 bar−1, and maintained high rejections towards Cs+, Sr2+ and Co2+, respectively. Furthermore, the membrane possessed a remarkable operational stability and an excellent anti-fouling property. These results confirmed the possibility of adopting crown ethers for RO membrane fabrication and verified their great potential for the practical application in removing radioactive elements from wastewater.

Amine-releasable Mediator In situ Repair Perovskites for Efficient and Stable Perovskite Solar Cells.

Residual lead iodide (PbI2) is deemed to a double-edged sword in perovskite film as small amounts of PbI2 are beneficial to the photovoltaic performance, but excessive will cause degradation of photovoltaic performance and stability. Herein, an in situ repair strategy has been developed by introducing amine-releasable mediator (methylammonium pyridine-2-carboxylic, MAPyA) to eliminate over-residual PbI2 and regulate the crystal quality of perovskite film. Notably, MAPyA can be partially decomposed into methylamine (MA) gas and pyridine-2-carboxylic (PyA) during high temperature annealing. The released MA can locally form liquid intermediate phase, facilitating the reconstruction of perovskite microcrystals and residual PbI2. Moreover, the leftover PyA is confirmed to effectively passivate the uncoordinated lead ions in final perovskite film. Based upon this, superior perovskite film with optimized crystal structure and holistic negligible PbI2 is acquired. The assembled device realizes outstanding efficiency of 24.06 %, and exhibits a remarkable operational stability that maintaining 87 % of its origin efficiency after continuous illumination for 1480 h. And the unencapsulated MAPyA-treated devices present significant uplift in humidity stability (maintaining ~93 % of the initial efficiency over 1500 h, 50-60 % relative humidity). Furthermore, the further optimization of this strategy with nanoimprint technology proves its superiority in the amplificative preparation for perovskite films.

Amine‐releasable Mediator In situ Repair Perovskites for Efficient and Stable Perovskite Solar Cells

AbstractResidual lead iodide (PbI2) is deemed to a double‐edged sword in perovskite film as small amounts of PbI2 are beneficial to the photovoltaic performance, but excessive will cause degradation of photovoltaic performance and stability. Herein, an in situ repair strategy has been developed by introducing amine‐releasable mediator (methylammonium pyridine‐2‐carboxylic, MAPyA) to eliminate over‐residual PbI2 and regulate the crystal quality of perovskite film. Notably, MAPyA can be partially decomposed into methylamine (MA) gas and pyridine‐2‐carboxylic (PyA) during high temperature annealing. The released MA can locally form liquid intermediate phase, facilitating the reconstruction of perovskite microcrystals and residual PbI2. Moreover, the leftover PyA is confirmed to effectively passivate the uncoordinated lead ions in final perovskite film. Based upon this, superior perovskite film with optimized crystal structure and holistic negligible PbI2 is acquired. The assembled device realizes outstanding efficiency of 24.06 %, and exhibits a remarkable operational stability that maintaining 87 % of its origin efficiency after continuous illumination for 1480 h. And the unencapsulated MAPyA‐treated devices present significant uplift in humidity stability (maintaining ~93 % of the initial efficiency over 1500 h, 50–60 % relative humidity). Furthermore, the further optimization of this strategy with nanoimprint technology proves its superiority in the amplificative preparation for perovskite films.

Enhancing the Efficiency and Stability of Perovskite Solar Cells through Defect Passivation and Controlled Crystal Growth Using Allantoin.

In this study, we present a robust approach that concurrently manages crystal growth and defect passivation within the perovskite layer through the introduction of a small molecule additive─allantoin. The precise regulation of crystal growth in the presence of allantoin yields perovskite films characterized by enhanced morphology, larger grain size, and improved grain orientation. Notably, the carbonyl and amino groups present in allantoin passivate under-coordinated Pb2+ and I- defects, respectively, through molecular interactions. Trap density in the perovskite layer is measured, and it is 0.39 × 1016 cm-3 for the allantoin-incorporated device and 0.83 × 1016 cm-3 for the pristine device. This reduction in defects leads to reduced trap-assisted nonradiative recombination, as confirmed by the photoluminescence, transient photo voltage, and impedance measurements. As a result, when these allantoin-incorporated perovskite films are implemented as the active layer in solar cells, a noteworthy efficiency enhancement to 20.63% is attained, surpassing the 18.04% of their pristine counterparts. Furthermore, devices with allantoin exhibit remarkable operational stability, maintaining 80% of their efficiency even after 500 h of continuous illumination, whereas the pristine device degraded to 65% of its initial efficiency in 400 h. Also, allantoin-incorporated devices exhibited exceptional stability against high humidity and elevated temperatures.

Synchronous Elimination of Excess Photoinstable PbI2 and Interfacial Band Mismatch for Efficient and Stable Perovskite Solar Cells.

Eliminating the undesired photoinstability of excess lead iodide (PbI2 ) in the perovskite film and reducing the energy mismatch between the perovskite layer and heterogeneous interfaces are urgent issues to be addressed in the preparation of perovskite solar cells (PVSCs) by two-step sequential deposition method. Here, the 1-ethyl-3-methylimidazolium tetrafluoroborate (EMIMBF4 ) is employed to convert superfluous PbI2 to more robust 1D EMIMPbI3 which can withstand lattice strain, while forming an interfacial dipole layer at the SnO2 /perovskite interface to reconfigure the interfacial energy band structure and accelerate the charge extraction. Consequently, the unencapsulated PVSCs device attains a champion efficiency of 24.28 % with one of the highest open-circuit voltage (1.19 V). Moreover, the unencapsulated devices showcase significantly improved thermal stability, enhanced environmental stability and remarkable operational stability accompanied by 85 % of primitive efficiency retained over 1500 h at maximum power point tracking under continuous illumination.

Synchronous Elimination of Excess Photoinstable PbI2 and Interfacial Band Mismatch for Efficient and Stable Perovskite Solar Cells

AbstractEliminating the undesired photoinstability of excess lead iodide (PbI2) in the perovskite film and reducing the energy mismatch between the perovskite layer and heterogeneous interfaces are urgent issues to be addressed in the preparation of perovskite solar cells (PVSCs) by two‐step sequential deposition method. Here, the 1‐ethyl‐3‐methylimidazolium tetrafluoroborate (EMIMBF4) is employed to convert superfluous PbI2 to more robust 1D EMIMPbI3 which can withstand lattice strain, while forming an interfacial dipole layer at the SnO2/perovskite interface to reconfigure the interfacial energy band structure and accelerate the charge extraction. Consequently, the unencapsulated PVSCs device attains a champion efficiency of 24.28 % with one of the highest open‐circuit voltage (1.19 V). Moreover, the unencapsulated devices showcase significantly improved thermal stability, enhanced environmental stability and remarkable operational stability accompanied by 85 % of primitive efficiency retained over 1500 h at maximum power point tracking under continuous illumination.

Electrocatalytic Coenhancement of Bimetallic Polyphthalocyanine-Anchored Ru Nanoclusters Enabling Efficient Overall Water Splitting at Ampere-Level Current Densities.

Efficient electrocatalysts capable of operating continuously at industrial ampere-level current densities are crucial for large-scale applications of electrocatalytic water decomposition for hydrogen production. However, long-term industrial overall water splitting using a single electrocatalyst remains a major challenge. Here, bimetallic polyphthalocyanine (FeCoPPc)-anchored Ru nanoclusters, an innovative electrocatalyst comprising the hydrogen evolution reaction (HER) active Ru and the oxygen evolution reaction (OER) active FeCoPPc, engineered for efficient overall water splitting are demonstrated. By density functional theory calculations and systematic experiments, the electrocatalytic coenhancement effect resulting from unique charge redistribution, which synergistically boosts the HER activity of Ru and the OER activity of FeCoPPc by optimizing the adsorption energy of intermediates, is unveiled. As a result, even at a large current density of 2.0 A cm-2 , the catalyst exhibits low overpotentials of 220 and 308mV, respectively, for HER and OER. It exhibits excellent stability, requiring only 1.88V of cell voltage to achieve a current density of 2.0 A cm-2 in a 6.0m KOH electrolyte at 70°C, with a remarkable operational stability of over 100 h. This work provides a new electrocatalytic coenhancement strategy for the design and synthesis of electrocatalyst, paving the way for industrial-scale overall water splitting applications.

NiMo-MOF-Derived Carbon-Armored Ni4Mo Alloy of an Interwoven Nanosheet Structure as an Outstanding pH-Universal Catalyst for Hydrogen Evolution Reaction at High Current Densities

Development of highly efficient and stable non-precious metal-based pH-universal catalysts for hydrogen evolution reaction (HER) at high current densities remains challenging for water electrolysis-based green hydrogen production. Herein, a simple solvothermal process was developed to synthesize a NiMo metal-organic framework (MOF), from which a carbon-armored Ni4Mo alloy of an interwoven nanosheet structure was derived with a two-stage thermal treatment, to serve as a high-performance pH-universal HER catalyst. It requires low overpotentials of 22, 48, and 98 mV to achieve a current density of -10 mA cm-2 and 192, 267, and 360 mV to deliver an ultrahigh current density of -500 mA cm-2 in alkaline, acidic, and neutral media, respectively, and exhibits remarkable operational stability at an ultrahigh initial current density of -500 mA cm-2 for over 50 h, making it promising for applications in large-scale green hydrogen production. The success can be attributed to the unique catalyst design of a carbon-armored, composition-optimized NiMo alloy of an advantageous nanostructure of interwoven nanosheets for enhanced utilization of active sites and mass transfer of electrolytes and gaseous products, made possible with a MOF-derivation fabrication approach.

Dual-oxidation-induced lattice disordering in a Prussian blue analog for ultrastable oxygen evolution reaction performance.

Enriching the active sites and enhancing the intrinsic activity of a single site are two basic strategies for improving the activity toward the electrocatalytic oxygen evolution reaction (OER), and designing an advanced microstructure with a boosted pre-oxidation process can further guarantee durability toward long-term catalysis. Herein, we propose a dual oxidation strategy of a Co Prussian blue analog (Co PBA), which simultaneously achieves Co3+ active site enrichment, in situ CeO2 decoration and lattice disordering with abundant undercoordinated sites, realizing highly efficient and ultrastable OER performance. The dual oxidation process can induce the enrichment of high-valence Co ions by combined chemical oxidation and d-f electron coupling compared to the singly oxidized catalysts, thereby providing more active sites with enhanced intrinsic activity for the early triggered OER process. In addition, the disordered lattice can provide abundant reactive Co sites for the pre-oxidation process, thereby leading to obvious activation of the catalysts and remarkable operational stability due to the substantially accumulated Co3+ sites. Benefitting from the structural advantages of lattice-disordered dual-oxidized Co PBA nanocages, a low overpotential of 240mV can be achieved for a 10mAcm-2 current density, and the large catalytic current density and intrinsic activity are among the best compared to those of previously reported PBA-based and PBA-derived catalysts and even RuO2 and IrO2. In addition, ultrastable OER behavior with a 263% activity enhancement in 150h can result, making the dual-oxidized catalyst a promising candidate for water electrolysis.

Green synthesis of isopropyl palmitate using immobilized Candida antarctica lipase: Process optimization using response surface methodology

This work aims to produce isopropyl palmitate (IPP), a common emollient ester in a solvent-free system. An esterification reaction between isopropyl alcohol (IPA) and palmitic acid (PA) was performed in a closed batch reactor using immobilized Candida antarctica lipase as a biocatalyst. Reaction conditions were optimized using response surface methodology based on a five-level, three-variable composite design. The interactive effects of conditions on the IPP yield were investigated in the following ranges: IPA-to-PA molar ratio of 3:1–15:1, 1%–4% (w/w) Novozym 435, and 1%–10% (w/w) molecular sieves. The optimum conditions were IPA-to-PA molar ratio of 15:1, 4% w/w of Novozym 435, and 10% w/w of molecular sieves at 60°C and 150 RPM for 2.5 h. The maximum experimental and predicted conversion values were 90.00% and 90.92%, respectively. Moreover, Novozym 435 exhibited remarkable operational stability because it was used for 15 cycles without considerably losing its original activity. In studying the feasibility of the proposed method, a process flow diagram was suggested to perform the semicontinuous production of IPP in a solvent-free medium.

Soft perovskites stabilized by robust heterojunctions

Rapid progress has recently been made in the development of perovskite solar cells (PSCs) with power conversion efficiencies (PCEs) that are now comparable with those of crystalline Si, the traditional and well-established solar cell technology. Recently in <i>Science</i>, Fang and co-workers reported a PSC in an inverted configuration with a high efficiency of >24% (23.5% certified) and remarkable operational stability. In this work, robust heterojunctions were constructed at the interface to suppress ion migration and favorably adjust the interfacial energy band alignment, addressing two major issues associated with the poor PCEs and stability of inverted PSCs.

Production and immobilization of \u03b2-glucanase from Aspergillus niger with its applications in bioethanol production and biocontrol of phytopathogenic fungi

β-Glucanase has received great attention in recent years regarding their potential biotechnological applications and antifungal activities. Herein, the specific objectives of the present study were to purify, characterize and immobilize β-glucanase from Aspergillus niger using covalent binding and cross linking techniques. The evaluation of β-glucanase in hydrolysis of different lignocellulosic wastes with subsequent bioethanol production and its capability in biocontrol of pathogenic fungi was investigated. Upon nutritional bioprocessing, β-glucanase production from A. niger EG-RE (MW390925.1) preferred ammonium nitrate and CMC as the best nitrogen and carbon sources, respectively. The soluble enzyme was purified by (NH4)2SO4, DEAE-Cellulose and Sephadex G200 with 10.33-fold and specific activity of 379.1 U/mg protein. Tyrosyl, sulfhydryl, tryptophanyl and arginyl were essential residues for enzyme catalysis. The purified β-glucanase was immobilized on carrageenan and chitosan with appreciable yield. However, the cross-linked enzyme exhibited superior activity along with remarkable improved thermostability and operational stability. Remarkably, the application of the above biocatalyst proved to be a promising candidate in liberating the associate lignocellulosic reducing sugars, which was utilized for ethanol production by Saccharomyces cerevisiae. The purified β-glucanase revealed an inhibitory effect on the growth of two tested phytopathogens Fusarium oxysporum and Penicillium digitatum.

Design of binder-free hierarchical Mo-Fe-Ni phosphides nanowires array anchored on carbon cloth with high electrocatalytic capability toward hydrogen evolution reaction

It is of immense importance to design and explore efficient electrocatalysts based on low-cost noble-metal free nanostructures toward hydrogen evolution reaction (HER), which remains an immense challenge. Herein, we designed a novel tri-metal phosphides based on Mo-Fe-Ni phosphides nanowires (Mo-Fe-Ni-P NWs) that directly grown on CC through a facile and simple hydrothermal process followed by a phosphorization step in the presence of NaH2PO2 as the P source. Outstandingly, benefiting from the unparalleled hierarchical NWs structure with large surface areas, open channels for effective releasing of gas products, and also special electronic structure engineering with rapid mass/electron transport, the resulting advanced binder-free Mo-Fe-Ni-P NWs@CC renders supreme HER performance in the KOH (alkaline) electrolyte. At an overpotential as low as 75 mV, it renders a current density of 10 mA cm−2. More importantly, it can achieve remarkable operational stability that is very desirable for practical application. Our design exhibits a rational strategy for the fabrication of advanced binder-free ternary metal phosphide NWs as a noble-metal free HER electrocatalyst toward high efficient with low cost H2 production.

γ-In2S3 nanosheets-composed flowerlike nanostructure doped by Al3+ ions with optimal electronic structure and decreased work function of γ-In2S3 for CO2 electroreduction to formate

It is an urgent imperative to convert CO2 molecules into valuable chemicals or fuels for mitigating the greenhouse effect and energy dilemma. Herein, γ-In2S3 nanosheets-composed flowerlike nanostructure doped by tunable amount of Al3+ ions was fabricated by a one-step solution-phase avenue for efficient CO2ER to formate. The particular nanosheets-composed flowerlike nanostructure exhibited good gas-permeable behavior, enlarging the capacity of CO2 adsorption and accelerating the mass-transport efficiency. The Al dopant in γ-In2S3 optimized the electronic structure of γ-In2S3, which enhanced the carrier density, conductivity, and exposed active sites. Besides, Al doping reduced the work function of γ-In2S3, which brought about the fast Faradaic process of CO2 activation and speeded up the subsequent reduction reaction. The optimal Al4.8%-In2S3 displayed the maximal formate Faradaic efficiency (FEHCOO–) of 91.2% at −1.0 V and maintained with a high FEHCOO–> 80% in a potential range of −0.9 to −1.2 V. Moreover, it exhibited a high formate energy efficiency (EEHCOO–) of 58.5% at −1.0 V and kept with a high EEHCOO–> 50% in a potential range of −0.9 to −1.2 V. Besides, Al4.8%-In2S3 delivered the partial current density of 23 mA cm−2 at −1.0 V for formate and increased to 31.7 mA cm−2 at −1.2 V. It also maintained over 90.8% of FEHCOO– and the current value decayed less than 2% after 14 h continuous electrocatalysis at −1.0 V, exhibiting remarkable operational stability in CO2ER. This work optimized electronic structure of metal chalcogenides by heterocations doping toward highly active and selective CO2ER to formate and beyond.

Achieving stable and high-efficiency (>21%) lead halide perovskite solar cells with δ-CsPbI2Br seed–assisted growth strategy

Recently, mixed cation-halide perovskites have become particularly interesting for high-performance perovskite solar cells (PSCs) owing to their near-ideal bandgap. Nevertheless, mixed cation-halide perovskites prepared via the existing methods are often subject to high defect density and poor stability, especially the sequential deposition methods in view of the difficulty of incorporating cesium cations (stabilizer). Herein, a simple and effective approach of δ-CsPbI2Br seed–assisting sequential deposition is developed. It is revealed that introducing δ-CsPbI2Br seeds into PbI2 film could not only effectively incorporate Cs+ into the mixed cation-halide perovskite film but also afford δ phase crystal lattices to promote the growth of α phase perovskites during annealing. Such a process can prepare high-quality perovskite film with larger grain size, lower defect density, and longer photoluminescence carrier lifetime (1658 ns). In addition, the thermal stability and humidity stability of the perovskite film are significantly boosted. Consequently, the optimized device delivers a champion efficiency of 21.62%, with an average efficiency of 1.5% higher than that of the control device. In addition, the unencapsulated device exhibits remarkable operational stability, retaining ~92% of the initial efficiency after aging for 1000 h in ambient air. This work provides insight for further preparing the high-quality perovskite film and improving the performance of PSCs.

Sandwiched electrode buffer for efficient and stable perovskite solar cells with dual back surface fields

<h2>Summary</h2> With the rapid progress of perovskite solar cells (PSCs), both high efficiency and sufficient stability are required simultaneously for their real-life application, wherein interfaces play an essential role. In this work, we develop sandwiched electrode buffer (SEB) with respect to the hole-transport layer (HTL), wherein dual back surface fields are implemented at two interfaces in relevance. The SEB bridges the absorber to the back electrode with the desired band alignment and multi-defect passivation effects, which stabilize the perovskite, HTL, and metal electrodes. Accordingly, planar n-i-p PSCs with SEB achieve an efficiency of 23.9% (certified 23.4%). Notably, they exhibit a remarkable operational stability with only a 3% efficiency decline for 2,000 h maximum power point tracking under 1-Sun illumination. Furthermore, the devices also show excellent thermal stability and humidity stability. Therefore, the SEB configuration boosts both efficiency and stability of PSCs, which paves the way for the commercialization of perovskite optoelectronics.

Co(OH)2 Nanosheets Array Doped by Cu2+ Ions with Optimal Electronic Structure for Urea‐Assisted Electrolytic Hydrogen Generation

AbstractUrea electrolysis supplies a great potential in energy‐saving hydrogen generation accompanied by simultaneous urea‐containing wastewater remediation. Herein, the Co(OH)2 nanosheets arrays doped by different amount of Cu2+ ions were prepared via a one‐step solution‐phase method for urea‐assisted electrolytic hydrogen generation. The Cu integration can regulate electronic structure, activate Co active sites at low potential, and optimize the charge transfer properties and adsorption states of the catalyst. Moreover, the partially distorted cobalt surroundings caused by Cu dopant in the catalyst is conductive to favor the adsorption of urea and water molecules to the active sites. The optimal Cu6.2%‐Co(OH)2 nanosheets array exhibited superior urea oxidation reaction (UOR) and hydrogen evolution reaction (HER) performances. Assembling an overall urea electrolyzer using two Cu6.2%‐Co(OH)2 electrodes gave rise to very small voltages of 1.389 V for 10 mA cm−2 and 1.781 V for a high current density of 500 mA cm−2 with remarkable operational stability. The Cu2+ ions doping strategy can be extended to a series of Ni‐based compounds with adjustable electronic structures for boosting the activities of UOR and HER.