Bimetallic CuCo Research Articles

Anion Doping as a “Trigger” to Modulate Defect‐Tailored Dielectric Coupling for Ultrathin Microwave Absorber

AbstractAnion doping engineering is recognized as a prospective strategy to adjust the electronic configuration and transport capacity of carbon‐based magnetoelectric hybrids and to optimize defects for the modulation of electromagnetic (EM) properties. This study effectively accomplishes an overwhelming enhancement in the dielectric coupling between conduction and polarization for the CuCo bimetallic/carbon system by employing in situ (N, O)/ex situ (S, Se) doping and defect modulation strategies. The well‐designed lattice distortions are facilitated by the large atomic radii (Se) intercalated carbon skeleton and the bimetallic CuCo, which activate the reinforcement of the dipole polarization in the high‐frequency region. Interestingly, an appropriate number of vacancies acts as “electron traps” to accelerate the local charge redistribution, endowing the system with extremely strong electronic interactions and interface‐induced polarization. It is remarkable that the ultra‐thin feature (1.8 mm) is able to achieve an extraordinary microwave attenuation (‒56.1 dB). Additionally, specific defect upgrading of anionic Se doping beneficially hinders the development of phonon transmission, conferring Cu2Se/CoSe2/NC‐Se aerogel outstanding infrared stealth capabilities along with inheriting the advantages of traditional carbon‐based hybrids (lightness, compressive/structural stability, and hydrophobicity/anti‐corrosive properties). This research offers distinctive perspectives on the advanced design of multifunctional absorbers in complex environments.

Enhanced bimetallic CuCo nanoparticles on nitrogen-doped carbon for selective hydrogenation of furfural to furfuryl alcohol through strong electronic interactions

Bimetallic CuCo catalysts with different Cu to Co ratios on N-doped porous carbon materials (N-C) were achieved using impregnation method and applied in the hydrogenation of furfural (FAL) to furfuryl alcohol (FOL). The high hydrogenation activity of FAL over Cu1Co1/N-C was originated from the synergistic interactions of Cu and Co species, where Co0 and Cu0 simultaneously adsorb and activate H2, and Cu+ served as Lewis acid sites to activate C═O. Meanwhile, electrons transfer from Cu to Co promoted the formation of Cu+. In situ Fourier transform infrared spectroscopy analysis indicated that Cu1Co1/N-C adsorbed FAL with a tilted η1-(O) configuration. The superior Cu1Co1/N-C showed excellent adsorbed ability towards H2 and FAL, but weak adsorption for FOL. Therefore, Cu1Co1/N-C possessed 93.1% FAL conversion and 99.0% FOL selectivity after 5 h reaction, which also exhibited satisfactory reusability in FAL hydrogenation for five cycles.

Surface composition and electronic properties of Co-Cu mixed oxalates: A detailed XPS analysis

X-ray photoelectron spectroscopy and X-ray diffraction were employed to characterize the structure, surface composition, atoms’ chemical state and electronic structure of bimetallic Co-Cu oxalates with a nominal composition of Co0.75Cu0.25C2O4, Co0.5Cu0.5C2O4 and Co0.33Cu0.67C2O4. High-resolution core-level spectra of the components, X-ray induced Cu L3VV Auger spectra and valence band spectra are presented for these oxalates along with a detailed analysis of a number of spectral parameters in comparison with those for monometallic Co and Cu oxalates. A consistent variation of different spectral parameters is considered in terms of changes in the strength of Me–O bonding. Due to charge transfer processes, Co-rich Co0.75Cu0.25C2O4 (Co/Cu = 3) oxalate displays the highest degree of covalency of Co–O bonds and ionicity of Cu–O bonds compared to CoC2O4, CuC2O4 and the other Co-Cu oxalates. The role of Cu1+ ions either initially present in Cu-containing oxalates or progressively accumulated during their X-ray irradiation is discussed in terms of strengthening/weakening of interatomic Me–O bonds.

Silica Confinement for Stable and Magnetic Co-Cu Alloy Nanoparticles in Nitrogen-Doped Carbon for Enhanced Hydrogen Evolution.

Ammonia borane (AB) with 19.6 wt % H2 content is widely considered a safe and efficient medium for H2 storage and release. Co-based nanocatalysts present strong contenders for replacing precious metal-based catalysts in AB hydrolysis due to their high activity and cost-effectiveness. However, precisely adjusting the active centers and surface properties of Co-based nanomaterials to enhance their activity, as well as suppressing the migration and loss of metal atoms to improve their stability, presents many challenges. In this study, mesoporous-silica-confined bimetallic Co-Cu nanoparticles embedded in nitrogen-doped carbon (CoxCu1-x@NC@mSiO2) were synthesized using a facile mSiO2-confined thermal pyrolysis strategy. The obtained product, an optimized Co0.8Cu0.2@NC@mSiO2 catalyst, exhibits enhanced performance with a turnover frequency of 240.9 molH2 ⋅ molmetal ⋅ min-1 for AB hydrolysis at 298 K, surpassing most noble-metal-free catalysts. Moreover, Co0.8Cu0.2@NC@mSiO2 demonstrates magnetic recyclability and extraordinary stability, with a negligible decline of only 0.8 % over 30 cycles of use. This enhanced performance was attributed to the synergistic effect between Co and Cu, as well as silica confinement. This work proposes a promising method for constructing noble-metal-free catalysts for AB hydrolysis.

Bimetallic CuCo nanoparticles optimized hydrogen generation active centers thereby significantly enhancing TiO2 photocatalytic activity

Bimetallic nanostructures are currently a hot pot material among many hydrogen generation co-catalysts. In this study, CuCo bimetallic nanostructures were formed by introducing Co into Cu as the co-catalyst for TiO2. Characterization results from XRD, XPS, and TEM indicated the successful preparation of the high-crystallinity, impurity-free CuCo/TiO2 photocatalyst, with CuCo bimetallic nanoparticles uniformly dispersed on TiO2. After the addition of Co, density functional theory (DFT) calculations showed that the free energy of H adsorption on the Cu site was optimized from 0.27 eV to −0.56 eV, which was beneficial for hydrogen production from TiO2. Electrochemical characterization, photoluminescence (PL) spectroscopy, infrared (IR) thermography, and finite difference in time domain (FDTD) results showed that the bimetallic CuCo acted as the co-catalyst, which increased the temperature of the reaction system, facilitated the separation of light-generated electron-hole pairs, and accelerated the charge transfer, thus promoting the photocatalytic hydrogen generation. The findings of the photocatalytic performance demonstrate that the photocatalyst exhibits the H2 generation rate of 1933.8 μmol/g/h, which is approximately 9 times greater than that of pure TiO2 (213.4 μmol/g/h), when the bimetallic CuCo is loaded in the molar ratio of 5:5 and at the loading amount of 2 wt%. Additionally, the photocatalyst demonstrated excellent catalytic stability, reaching 87.1% of the initial after 16 h of cycling tests. It is foreseen that further study and optimization of various metal couplings may enable the larger widespread application of bimetals as co-catalysts for hydrogen generation.

Integration of bimetallic CuCo into N-doping SiC hollow nanoreactor for pollutant removal coupled solar-driven cleanwater regeneration

Photothermal nanomaterials have showed great potential for development in simultaneous pollutant purification and freshwater recovery. In this study, a novel composite composed of hollow N-doping SiC porous hybrid network with the integration of CoCu bimetal species was constructed by a simple self-assembly and temperature-modulated approach. Such a hollow porous hybrid nanoreactor is endowed with abundant synergetic CuCo bimetallic reactive sites and polar pyrrolic N sites, which improves the enrichment of pollutants and intermetallic redox pairs. Ultrafine nanocrystals corresponding to Co2SiO4 over the hybrid framework can be evidenced by HRTEM technique. The experimental results showed that the optimal CoSiCu-6 degraded norfloxacin (NFX) by 90.7% in 10 min with a pseudo-first-order rate constant of 0.493 min−1, which was about 6.49 folds enhancement compared to Cu-free CoSi-6 counterparts, achieving a low reaction activation energy (18.02 kJ mol−1) during the reaction. Control experiments including anion interference and broad applicability for pollutants degradation were further explored, emphasizing the excellent performance of CoSiCu-6 in the practical contaminant removal. The mechanism study showed that, single linear oxygen (1O2) coupled with electron-transfer process work as the main activation routes dominating the degradation process. In addition, Co3+/Co2+/Cu2+ redox pairs and oxygen vacancies (Ov) play a key role in the PMS activation process. The obtained optimal catalyst was further explored for solar-driven photothermal interfacial water evaporation, showing a rational cleanwater recovery efficiency (∼1.3 kg m−2 h−1) from the polluted wastewater. In addition, monolith floatable evaporator was constructed by anchoring CoSiCu-6 onto a tailored melamine sponge foam via a calcium ion-triggered sodium alginate cross-linking strategy, affording an excellent evaporation performance (2.16 kg m−2 h−1) and coupled norfloxacin degradation efficiency (93.6%, within 5 min). This innovative monolithic evaporator made of CoCu integrated SiC hybrid nanosphere has a powerful dual function of rapidly degrading pollutants and facilitating solar-powered regeneration of contaminated wastewater due to its unique hollow porous structure and the CoCu bimetallic synergistic action that provides a rich set of reaction sites, which is promising for the treatment of complicated wastewater.

Bimetallic CoCu nanoparticles anchored on COF/SWCNT for electrochemical detection of carbendazim

Carbendazim (CBZ) is a widespread fungicide used in crop protection, but the CBZ residues in drinking water, fruits, and vegetables can also cause adverse impacts on public health due to direct exposure. In this paper, a ternary synergistic composite of bimetallic CoCu nanoparticles anchored on covalent organic framework/single-walled carbon nanotube (CoCu/COF/SWCNT) was prepared and further applied as an electrochemical sensing platform for detecting CBZ. The sensor showed a sensitive response performance toward CBZ oxidation, as a result of the enhanced charge transfer ability, large electrochemically active surface area, and high electro-catalytic activity from the rational integration of the ternary components in CoCu/COF/SWCNT. Under the optimal conditions, the proposed sensor exhibited a detection range of 0.001 to 10 μM and a limit detection of 0.65 nM for CBZ detection. In addition, the sensor displayed practical feasibility for the determination of CBZ in water and pear samples with a recovery of 96.1 % to 102.1 %.

Low-crystalline CoCu–MgAl oxide nano sheet heterostructures immobilized by crab shell-derived phosphorus-doped carbon for hydrazine dehydrogenation

Background: Hydrogen production and transportation can be made safe and efficient through hydrazine dehydrogenation heterogeneous catalysis. Methods: The phosphate mediation synthesized CoCu@MgAl2O4 Nano sheets (0.89 nm in diameter) are anchored to crab shell-derived carbon (CSDC). Bimetallic CoCu2+ must be strongly absorbed and dispersed in the phosphate-modified CSDC to produce highly dispersed ultrafine NPs. The phosphate group successfully dispersed the ultrafine CoCu NPs with a size of 1.24 nm on MgAl2O4/(P)CSDC. The optimized Co0.7Cu0.3@MgAl2O4/(P)CSDC system has exceptional catalytic activity for hydrazine dehydrogenation, with a TOF value of 11,070 h−1 at 298 K and 100% H2 selectivity. Significant findings: The introduction of the phosphate group favors the production of ultrafine and well-dispersed bimetallic CoCu NPs and also influences the electronic structure of metal catalytic sites. This implies that the prepared catalyst could improve the catalytic performance for catalyzing hydrazine dehydrogenation. This research might lead to an effective system for developing high-performance bimetallic Nano systems for future catalytic applications.

Cu-Co Dual-Atom Catalysts Supported on Hierarchical USY Zeolites for an Efficient Cross-Dehydrogenative C(sp2)-N Coupling Reaction.

A cross-coupling reaction via the dehydrogenative route over heterogeneous solid atomic catalysts offers practical solutions toward an economical and sustainable elaboration of simple organic substrates. The current utilization of this technology is, however, hampered by limited molecular definition of many solid catalysts. Here, we report the development of Cu-M dual-atom catalysts (where M = Co, Ni, Cu, and Zn) supported on a hierarchical USY zeolite to mediate efficient dehydrogenative cross-coupling of unprotected phenols with amine partners. Over 80% isolated yields have been attained over Cu-Co-USY, which shows much superior reactivity when compared with our Cu1 and other Cu-M analogues. This amination reaction has hence involved simple and non-forceful reaction condition requirements. The superior reactivity can be attributed to (1) the specifically designed bimetallic Cu-Co active sites within the micropore for "co-adsorption-co-activation" of the reaction substrates and (2) the facile intracrystalline (meso/micropore) diffusion of the heterocyclic organic substrates. This study offers critical insights into the engineering of next-generation solid atomic catalysts with complex reaction steps.

Hydrolysis of Ammonia Borane for Hydrogen Generation on Bimetallic CoCu Catalysts: Regulation of Synergistic Effect

Hydrolysis of Ammonia Borane for Hydrogen Generation on Bimetallic CoCu Catalysts: Regulation of Synergistic Effect

LaCo1-x-yCuxTiyO3/KIT-6 perovskites: synthesis and catalytic behavior in syngas conversion to higher alcohols.

Highly dispersed LaCo1-x-yCuxTiyO3/KIT-6 perovskites were synthesized by the citrate method with inert mesoporous KIT-6 addition. The KIT-6 matrix was removed by dissolution in 7% NaOH aqueous solution. The dispersity of perovskites probably varies depending on the largest cation and its content at the B position of the perovskite ABO3 structure. The CoS=23+/CoS=03+ ratio increases with the increase in copper content and in the presence of Ti4+. It may be explained by the compensation of the distortion of the perovskite structure. The maximum syngas conversion is achieved at nCo/nCu = 7/3. At a higher copper content, the activity of the samples decreases due to the formation of large copper particles (up to 40 nm) in the course of the reduction. The selectivity for alcohols increases with an increase in the proportion of copper and reaches maximum values at a ratio of nCo/nCu close to 1. The distribution of alcohols is the same for all samples, except for LaCo0.35Cu0.35Ti0.3O3/KIT-6. It can be assumed that the synthesis of alcohols proceeds on bimetallic CoCu particles 3 nm in size and cobalt particles 4-6 nm in size, most likely enriched with copper on the surface.

Bimetallic CuCo nanocrystals to tailor absorption energy of intermediators for efficient electrochemical nitrate conversion to ammonia in neutral electrolyte

Electrocatalytic nitrate reduction to ammonia (NRA) is a promising approach to solve nitrate elimination for ammonia synthesis under mild conditions, but there still lack efficient NRA electrocatalysts. Herein, we developed a bimetallic CuCo nanocrystal with 2.5 at.% Co to Cu, which achieves 100% nitrate conversion rate and also maintains a high NH3 Faradaic efficiency of 95% at −0.65 V vs. RHE in neutral electrolyte. More importantly, its high catalytic activity enables a conversion rate of more than 97% for nitrate to ammonia. Density functional theory calculation reveals that the excellent catalytic activity is attributed to a strong NO3− absorption together with suppression of hydrogen evolution reaction. This work provides a new insight for developing highly active and selective NRA electrocatalysts.

Kinetically accelerated lithium storage in dumbbell-like Co/Cu@CN composite derived from a bimetallic-organic framework

Compared with single-component anode materials with obvious shortcomings, multi-component structured carbonaceous composites are expected to possess higher electrochemical activity and fast diffusion kinetics. Therefore, they show promising prospects in electrochemical energy storage applications. However, their synthesis is also challenging. Here, we report the preparation of dumbbell-shaped rod-like N-doped bimetallic CuCo carbonaceous composites (Cu/Co@CN) as high-performance anode materials for lithium storage using a bimetal-organic framework (MOF)-derived synthesis method. This unique dumbbell-shaped rod-like structure obtained by a facile solid-state sintered metal-organic framework can effectively withstand volumetric strain and can be beneficial towards structural stability. Highly dispersed Cu/Co and carbonaceous materials exert compositional synergistic effects to improve electrical conductivity and lithium-ion storage capacity, in turn enhancing the electrochemical activity. Abundant N doping and dumbbell rod structure provide additional active sites for directing Li reactions and accelerating ion/electron mobility. The results show that Cu/Co@CN-500 exhibits outstanding electrochemical performance, including remarkable specific capacity (1115.3 mAh g−1 at 200 mA g−1), extraordinary rate performance (419.5 mAh g− even at 2 A g−1) and good cycling stability (545.4 mAh g−1 upon 750 cycles at 1000 mA g−1). These bimetallic carbonaceous composites with ideal structure, composition, and properties showed a great potential towards being qualified as anode candidates for advanced lithium storage.

Catalytic oxidation of toluene over Co-Cu bimetallic oxides derived from CoyCu3−y-MOF-74

As a precursor material, CoyCu3−y-MOF-74 has been synthesized by using a cost-effective and environmentally friendly mechanochemical method. It had a uniform nano-morphology and a controllable stoichiometric composition. By calcinating the CoyCu3−y-MOF-74 material, a bimetallic Co-Cu oxide catalytic material, with the formula M-CoyCu3−yOx, could, thereafter, be prepared. It was later on used for catalytic oxidation of toluene. The effect of calcination temperature and Co/Cu molar ratio on the redox properties, catalytic activity, and structural properties of the catalyst, were also systematically studied. The M-Co2Cu1Ox catalyst showed a complete toluene conversion of 1000 ppm toluene at 225 ℃ and with a under weight hour space velocity of 30,000 ml/ (g h). The corresponding conversion temperature for 50% and 90% of the original amount of M-Co2Cu1Ox (i.e., T50 and T90) were 202 and 220 ℃, respectively. X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, and electron paramagnetic resonance (EPR) results also showed a high density of oxygen vacancies in M-Co2Cu1Ox. Also, in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) experiments indicated that benzaldehyde and benzoic acid were the main intermediates formed during the catalytic oxidation of toluene. In addition, the M-Co2Cu1Ox catalyst did also show an excellent durability and good water resistance by exposing it to a 5% water vapor for 24 h. Thus, the green and facile mechanical synthesis of the MOF-74 precursor has been proven to be very beneficial for the design and synthesis of a mixed metal oxide catalyst with a high toluene catalytic oxidation efficiency.

Tuning the electronic structure of bimetallic CoCu clusters for efficient hydrolysis of ammonia borane

Efficient and low cost catalysts for the hydrogen production from ammonia borane (AB) are highly required to build up the upcoming hydrogen economy. Here we demonstrated that the non-active material could be directly transformed to highly active catalyst for the hydrolysis of AB when the surface parts were stripped to form tiny clusters on graphene oxide (GO), with the presence of strong cluster-support interaction. Moreover, the catalytic activity can be greatly enhanced by further tuning the electronic structure of clusters with various compositions. As a result, the final bimetallic CoCu catalyst on GO can achieve a high total turnover frequency (TOF) value of 72.4 (H2) mol/(Cat-metal) mol·min with an activation energy of 47.8 kJ/mol, which is over 3 times higher than the monometallic clusters on GO. The cluster-support interaction has been clearly identified by synchrotron radiation X-ray absorption spectroscopy. An internal charge transfer from Cu to Co in the clusters can also be identified, which will weaken the B-N bond in AB and then effectively accelerate the hydrolysis of AB to achieve the high performance.

Electrochemical reduction of CO2 to CO on bimetallic CoCu–N–C catalyst

Electrochemical reduction of CO2 to valuable chemicals using electricity from renewable sources is a promising approach to realize the carbon cycle. Here, a novel bimetallic nitrogen-doped carbon catalyst (M-N-C, where M denotes the metal) CoCu–N–C electrocatalyst has been synthesized by pyrolyzing a copper-doped cobalt(II) acetate–phenanthroline complex formed from the metal acetates and 1,10-phenanthroline dissolved in ethanol. The optimal CoCu–N–C catalyst with molar ratio of Cu/(Co + Cu) = 0.15 displayed superior performance, enabling a faradaic efficiency of CO production of 76.5% at an overpotential of 0.57 V as well as an increased CO current density of 8.48 mA cm−2 at −0.98 V versus reversible hydrogen electrode (far superior than the Co–N–C of 4.20 mA cm−2 and Cu–N–C of 0.07 mA cm−2) and a decreased charge-transfer resistance compared with Co–N–C and Cu–N–C catalysts. The addition of Cu, which serves as a structure promoter to improve the dispersion of Co, thereby providing sufficient Co-Nx active sites for the electrochemical CO2 reduction reaction (CRR). Moreover, doping Cu changes the electronic environment around Co slightly and promotes the charge transfer capability so that reduces the energy barrier of potential-limiting energy, thereby improving the CRR performance of catalyst.

Bimetallic CuCo@Nitrogen/Carbon Nanoparticles as a Cathode Catalyst for Magnesium‐Air Batteries

AbstractMg‐air batteries are regarded as one of the most promising electrochemical energy storage and conversion devices. Developing high‐performance, low‐cost and durable non‐noble metal electrocatalysts for oxygen reduction reaction (ORR) at cathode is extremely critical for promoting the practical applications of Mg‐air batteries. The bimetallic M−N−C catalysts possess the superior ORR activity and stability due to the synergetic effect of metal atoms. Herein, prussian blue analogues (PBA) were employed as precursors to prepare bimetallic M−N−C electrocatalysts. The CuCo@N/C and Co@N/C were derived from CuCo−PBA and CoCo−PBA calcined under different temperatures. The bimetallic CuCo@N/C nanoparticles pyrolyzed at 800 °C (CuCo@N/C‐800) displays superior ORR performances and outstanding stability in alkaline and neutral electrolytes. The primary Mg‐air batteries assembled with the CuCo@N/C‐800 as the cathode catalyst displays better discharge performances than that of Co@N/C‐800. This work provides an effective strategy to synthesize bimetallic and non‐noble ORR catalysts for Mg‐air batteries.

Bimetallic CuCo Prussian blue analogue nanocubes induced chemiluminescence of luminol under alkaline solution for uric acid detection in human serum

In this paper, bimetallic CuCo Prussian blue analogue (CuCo PBA) nanocubes, synthesized through a self-assembly method, were found to induce chemiluminescence (CL) of luminol-NaOH since the catalytic oxidation activity of CuCo PBA. The CL intensity of luminol-NaOH system was enhanced about 50 times with the addition of CuCo PBA. When uric acid (UA) was added to the new luminol-NaOH-CuCo PBA system, the CL signal could be reduced significantly. Based on these, an enzyme-free CL sensor was constructed for UA detection with a linear response range from 0.30 to 5.00 μM, and detection limit of 0.16 μM (S/N = 3). The other common species in human serum didn’t affect UA detection. Furthermore, this CL sensor was successfully applied to detect the UA in human serum samples with high sensitivity. This work not only discovered the enzyme-like properties of CuCo PBA, but also broadened its application in CL bioassays.

Understanding the surface segregation behavior of bimetallic CoCu toward HMF oxidation reaction

Surface segregation is ubiquitous in multi-component materials and is of great important for catalysis but little is known on the surface structure under graphene encapsulation. Here, we show that the graphene encapsulated CoCu performs well for the electrocatalytic oxidation of 5-hydroxymethylfurfural (HMF) to 2,5-furandicarboxylic acid (FDCA) with the onset potential before 1.23 VRHE and a nearly 100% selectivity of FDCA under 1.4 VRHE. From the experimental results, the unprecedented catalytic performance was attributed to local structural distortion and sub-nanometer lattice composition of the CoCu surface. We accurately show the dispersed Cu doped Co3O4 nano-islands with a lot of edge sites on the bimetallic Co-Cu surface. While, the gradient components effectively facilitate the establishment of built-in electric field and accelerate the charge transfer. Theoretical and experimental results reveal that the surface Co and neighbouring Cu atoms in sub-nanometer lattice synergistically promote the catalysis of HMF. This work offers new insights into surface segregation in tuning the element spatial distribution for catalysis.

Electron-rich interface of Cu-Co heterostructure nanoparticle as a cocatalyst for enhancing photocatalytic hydrogen evolution

Heterogeneous nano-metal structures are widely used in the field of photocatalysis as an efficient cocatalyst, but the structure–activity relationship has not been elucidated clearly. In this work, a classical CuCo@C nanoparticle with a core of bimetallic CuCo and a carbon shell was used as a cocatalyst to explore and reveal the mechanism of interfacial effect for enhanced photocatalytic hydrogen evolution. It was found that the bimetallic CuCo had a heterogeneous structure with abundant Cu-Co interfaces. The desirable visible-light-driven photocatalytic hydrogen evolution rate of CuCo@C/g-C3N4 was much higher than that of Cu@C/g-C3N4, Co@C/g-C3N4, and superior to that of the control group loaded with 1 wt% Pt (Pt/g-C3N4). According to the experimental characterizations and density functional theory calculations, electrons were enriched at the Cu-Co interface, which can promote the electron-hole pairs separation and accelerate charge transfer of the g-C3N4 host photocatalysts. On the other hand, the surface carbon layer and Cu-Co interface modulated the H adsorption free energy on the CuCo@C, which was favorable for hydrogen evolution. It is conceivable that further investigating and tuning different metal interfaces will facilitate the large-scale application of bimetallic cocatalysts.