Search

Effective selective recycling of spent lithium‐ion batteries (S‐LIBs) and giving recycled products a “second life” are crucial for advancing energy supply circularity, environmental and economic sustainability development. However, separating metal compounds with similar charge differences requires substantial energy, water, and chemical inputs. Herein, an innovative strategy is present for selective recycling S‐LIBs by photoexcitation inspired by the Hard Soft Acid Base (HSAB) principle. Theoretical calculations and experimental results show that photoexcitation drives charge transfer and modulates subtle charge density differences among metal components, thereby enhancing their solubility disparity and facilitating metal separation. Remarkably, the photoexcitation‐induced metal separation factor reaches 46900 and the metal recovery efficiency approaches 100%, representing a significant improvement over non‐photoexcitation separation with a separation factor of non‐photoexcitation of merely 2.7. Through techno‐economic analysis, the viability of photoexcitation selective recycling technology has been confirmed as an eco‐friendly and economical approach for battery recycling. Furthermore, high‐value reuse of recovered Mn components is implemented. The Recycled Mn components are treated by calcination to obtain porous, defect‐rich Mn2O3, which showed a specific capacity of 613 mAh g−1 at 0.1 A g−1) in aqueous Zn‐ion batteries (AZIBs). This work provides fresh insight into recycling S‐LIBs and moving toward more sustainable storage technologies. [ABSTRACT FROM AUTHOR]

Cold‐chain transport is a crucial cross‐regional transmission pathway for severe acute respiratory syndrome coronavirus 2 and other microorganisms. In this study, the mode‐combination method is adopted for sterilization in a 1.138 m3 freezer by mixing effluent gases of NOx and O3 mode air discharges. The mixed gas can effectively inactivate Staphylococcus aureus in 10 mm ice within 3 h, which significantly surpasses O3 gas. Moreover, the inactivation effect of the mixed gas can penetrate deep into ice, contrasting with the surface effect of O3 gas. This disparity is linked to the difference in penetration depth of strong oxidizing long‐lived reactive species. This study validates the sterilization efficacy of cold atmospheric plasma in practical cold‐chain environment, critical for curbing infectious disease transmission. [ABSTRACT FROM AUTHOR]

Directly repairing end‐of‐life lithium‐ion battery cathodes poses significant challenges due to the diverse compositions of the wastes. Here, we propose a water‐facilitated targeted repair strategy applicable to various end‐of‐life batches and cathodes. The process involves initiating structural repair and reconstructing particle morphology in degraded LiMn2O4 (LMO) through an additional thermal drive post‐ambient water remanganization, achieving elemental repair. Compared to solid‐phase repair, the resulting LMO material exhibits superior electrochemical and kinetic characteristics. The theoretical analysis highlights the impact of Mn defects on the structural stability and electron transfer rate of degraded materials. The propensity of Mn ions to diffuse within the Mn layer, specifically occupying the Mn 16d site instead of the Li 8a site, theoretically supports the feasibility of ambient water remanganization. Moreover, this method proves effective in the relithiation of degraded layered cathode materials, yielding single crystals. By combining low energy consumption, environmental friendliness, and recyclability, our study proposes a sustainable approach to utilizing spent batteries. This strategy holds the potential to enable the industrial direct repair of deteriorated cathode materials. [ABSTRACT FROM AUTHOR]

Photocatalytic synthesis of hydrogen peroxide (H2O2) is a potential clean method, but the long distance between the oxidation and reduction sites in photocatalysts hinders the rapid transfer of photogenerated charges, limiting the improvement of its performance. Here, a metal‐organic cage photocatalyst, Co14(L−CH3)24, is constructed by directly coordinating metal sites (Co sites) used for the O2 reduction reaction (ORR) with non‐metallic sites (imidazole sites of ligands) used for the H2O oxidation reaction (WOR), which shortens the transport path of photogenerated electrons and holes, and improves the transport efficiency of charges and activity of the photocatalyst. Therefore, it can be used as an efficient photocatalyst with a rate of as high as 146.6 μmol g−1 h−1 for H2O2 production under O2‐saturated pure water without sacrificial agents. Significantly, the combination of photocatalytic experiments and theoretical calculations proves that the functionalized modification of ligands is more conducive to adsorbing key intermediates (*OH for WOR and *HOOH for ORR), resulting in better performance. This work proposed a new catalytic strategy for the first time; i.e. to build a synergistic metal‐nonmetal active site in the crystalline catalyst and use the host–guest chemistry inherent in the metal‐organic cage (MOC)to increase the contact between the substrate and the catalytically active site, and finally achieve efficient photocatalytic H2O2 synthesis. [ABSTRACT FROM AUTHOR]

Plasma‐based technology has been widely applied in the biomedicine, agriculture, and environmental fields. In this study, a new application mode, namely plasma‐activated nebulized mist (PANM) was proposed. The saline was nebulized by the plasma‐activated air to form a mist, and the inactivation effects on Pseudomonas aeruginosa were analyzed based on the simulated respiratory tract. The PANM through the simulated trachea with different lengths or diameters, and the branched once or twice simulated respiratory tract exhibited effective inactivation effects. The PANM through the combined simulated trachea and pig trachea could also inactivate the bacteria on the inner wall of the pig trachea. This study supplied a potent alternative to antibiotics for the treatment of respiratory tract infections. [ABSTRACT FROM AUTHOR]

Structural variants of high‐nuclearity clusters are extremely important for their modular assembly study and functional expansion, yet the synthesis of such giant structural variants remains a great challenge. Herein, we prepared a lantern‐type giant polymolybdate cluster (L‐Mo132) containing equal metal nuclearity with the famous Keplerate type Mo132 (K‐Mo132). The skeleton of L‐Mo132 features a rare truncated rhombic triacontrahedron, which is totally different with the truncated icosahedral K‐Mo132. To the best of our knowledge, this is the first time to observe such structural variants in high‐nuclearity cluster built up of more than 100 metal atoms. Scanning transmission electron microscopy reveals that L‐Mo132 has good stability. More importantly, because the pentagonal [Mo6O27]n− building blocks in L‐Mo132 are concave instead of convex in the outer face, it contains multiple terminal coordinated water molecules on its outer surface, which make it expose more active metal sites to display superior phenol oxidation performance, which is more higher than that of K‐Mo132 coordinated in M=O bonds on the outer surface. [ABSTRACT FROM AUTHOR]

Interactions of cold atmospheric‐pressure plasma jets (APPJs) and water are important for water purification, chemical synthesis, medicine, and biotechnology. However, the reactivity and bactericidal effects of water activated with jets of different ionized gases remain unclear, especially in the commonly used helium (He)‐ and argon (Ar)‐APPJ systems. Here, He and Ar are used as working gases to produce APPJ for comparing the plasma‐induced aqueous reactive species and bacteria inactivation effects in solutions. Experimental results indicate that the Ar plasma jet shows a quicker propagation velocity and higher concentrations of gaseous reactive species, and the gas and electron temperature are different for the He and Ar plasma. Moreover, the higher concentration of aqueous reactive species, such as ∙OH, ∙O2−/ONOOH, H2O2, NO2−, and NO3−, and better bacterial inactivation effects are achieved by the Ar plasma treatment. Water deformation induced from plasma water is found as the reason for the different reactivity and bactericidal effects. Further validation experiments using a film with different pore diameters confirm that the molecular weight of the working gas influences the shape and stability of the cavity induced by the gas flow in the plasma jet, and plays a vital role in the production of aqueous reactive species with variable concentrations. [ABSTRACT FROM AUTHOR]

The non‐destructive repair of spent lithium‐ion batteries cathode materials has been the holy grail in the field of waste‐to‐resource research due to the potential for optimal environmental and economic benefits. Here, Mn deficiency and cationic disorder in degraded materials are discovered for the first time and the degraded crystal structure is repaired by the in situ upcycling process using a low‐carbon and economical technique. The repaired disordered LiMn2O4 (LMO) material can contribute higher capacity and greater stability than ordered LMO materials. This unexpected behavior is attributed to the in‐situ upcycling process that enhances the Li/Mn atomic disorder, thereby altering the electrochemical activity as well as the structural stability of the cathode material. Specifically, the Li/Mn disorder can effectively suppress the Jahn–Teller distortion and two‐phase phase transition and activate the activity of disordered Li, contributing to a stable high discharge capacity of upcycled material. The discovery of the Mn‐deficiency mechanism solves many doubts as to the conventional repair technology and can provide a more adequate theoretical guidance of the development of recycling technology together with the Li‐deficiency mechanism. The atomic disorder structure also provides guidance for the design of battery materials and promotes the sustainable development of future green lithium‐ion batteries. [ABSTRACT FROM AUTHOR]

Pollution from spent batteries is causing an environmental crisis, driving the development of innovative recycling and upcycling methods. Conventional recycling technologies are plagued by the technical barriers of high pollution, low efficiency, and poor product utilization. Herein, an innovative and sustainable method is reported of in situ selective and precise recycling of cathode scrap into high value‐added transition metal oxides, as well as in‐depth verification of their suitability as lithium‐ion batteries (LIBs) anodes. The recycled ZnMn2O4 material exhibits extremely high discharge specific capacity and performs well at high rates. This unique selective conversion technology, attributed to the co‐octahedral retention conversion, can be applied to obtain a variety of anode materials from aged cells. A successful demonstration of the reconversion of waste LiMn2O4 and LiCoO2 to obtain transition metal oxide materials provides the possibility of further efficient green recycling approaches for large‐scale applications. [ABSTRACT FROM AUTHOR]

Superior lithophilicity for the 3D host is essential to enable both uniform molten lithium (Li) infusion during synthesis and a low Li nucleation barrier during cycling. The wetting behavior between the host surface and molten Li can be reasonably predicted by the typical Wenzel model. Herein, inspired by the model, a lotus‐leaf‐like carbon nanotube (CNT)/NiO spheres hybrid structure is employed to improve the wettability and regulate Li plating/stripping. First, the CNTs interweave to form a highly conductive and robust sponge with accelerated Li+ transport and reinforced stability. Second, the embedded NiO microspheres possess the Li‐active nature. More importantly, the surface roughness caused by nano‐sized protuberances over its surface further stronger the lithiophilicity. By the in situ optical microscope and calculations, this multistage structure is proven to homogenize the Li deposition and inhibit dendrite growth. As a result, the composite anode enables excellent cycling performance at both symmetric and full cells. This design of micro/nanostructured host provides a new perspective on the development of an excellent wettable host for Li‐metal anode. [ABSTRACT FROM AUTHOR]

Effective and scalable recycling of spent lithium‐ion batteries is an urgent need to address the environmental pollution and resource consumption caused by improper disposal. Herein, a practical solution is presented to recover and increase the stability of the layered structure from scrap Li1−xCoO2 via high‐temperature supplementation of Li and Mg doping, without an extra synthesis step or cost. All the regenerated products exhibit better electrochemical performance compared with the commercial cathode material. Within the voltage window of 3.0–4.6 V, 5% Mg‐recovery LiCoO2 (LMCO) exhibits a high discharge capacity of 202.9 mA h g−1 at 0.2 C, and 3% Mg‐recovery LiCoO2 shows enhanced capacity retention of 99.5% at 0.2 C after 50 cycles and maintains 96.8% at 1 C after 100 cycles. This is because high‐temperature supplementing metal ions is beneficial for eliminating the cracks and nano‐impurity particles on the surface of spent materials, thereby restoring the layered structure and electrochemical performance. The excellent electrochemical performances of Mg‐recovery LiCoO2 are attributed to Mg ions doping, which can inhibit the release of lattice oxygen and stabilize the surface structure. This process maximizes the utilization of the spent materials and provides a novel perspective for the non‐constructive recovery of spent materials. [ABSTRACT FROM AUTHOR]

Antituberculosis drug-induced liver injury (ATDILI) has received increasing attention globally, which may limit the effectiveness of antituberculosis (anti-TB) treatment. Many host genetic determinants of ATDILI have been identified recently. As little knowledge is currently available about the association between aldehyde dehydrogenase 1 family member A1 (ALDH1A1) polymorphisms and ATDILI, the association between their variants and the susceptibility to ATDILI was investigated. A total of 747 patients with TB treated by first-line anti-TB drugs were prospectively enrolled at West China Hospital. Genomic DNA was extracted from the peripheral blood sample of each patient and seven single-nucleotide polymorphisms (SNPs) of ALDH1A1 gene were screened and genotyped with a custom-designed 2×48-plex SNP Scan TM kit. The patients were followed up monthly to monitor the development of ATDILI. The C allele and the CA genotype of rs7852860 were significantly associated with an elevated risk for ATDILI (p = .006 and 0.005, respectively), which was consistent with the results in the dominant and additive models. No allele, genotype, or genetic model of the other six SNPs (rs3764435, rs348471, rs63319, rs610529, rs7027604, rs8187876) were found to be associated with susceptibility to ATDILI. The findings first demonstrate that rs7852860 variants in ALDH1A1 gene is associated with susceptibility to ATDILI in the Chinese Han population. Validation studies with larger sample sizes and other ethnic groups are needed to confirm the findings. [ABSTRACT FROM AUTHOR]

CHESS is a new direct‐geometry inelastic spectrometer, which is planned for the Second Target Station (STS) at the Spallation Neutron Source (SNS) in Oak Ridge. It will take full advantage of the increased peak brilliance of the high‐brightness STS coupled moderators and of recent advances in instrument design and technology to achieve unprecedented performance for inelastic scattering in the cold energy range. This paper presents a conceptual design that addresses key requirements and technical solutions which are derived directly from the science case and anticipated use of the instrument. [ABSTRACT FROM AUTHOR]

Gemfibrozil is a fibrate drug used widely for dyslipidemia associated with atherosclerosis. Clinically, both gemfibrozil and its phase II metabolite gemfibrozil 1-O-β-glucuronide (gem-glu) are involved in drug-drug interaction (DDI). But the DDI risk caused by gem-glu between human and mice has not been compared. In this study, six volunteers were recruited and took a therapeutic dose of gemfibrozil for 3 days for examination of the gemfibrozil and gem-glu level in human. Male mice were fed a gemfibrozil diet (0.75%) for 7 days, following which a cocktail-based inhibitory DDI experiment was performed. Plasma samples and liver tissues from mice were collected for determination of gemfibrozil, gem-glu concentration and cytochrome p450 enzyme (P450) induction analysis. In human, the molar ratio of gem-glu/gemfibrozil was 15% and 10% at the trough concentration and the concentration at 1.5 h after the 6th dose. In contrast, this molar ratio at steady state in mice was 91%, demonstrating a 6- to 9-fold difference compared with that in human. Interestingly, a net induction of P450 activity and in vivo inductive DDI potential in mice was revealed. The P450 activity was not inhibited although the gem-glu concentration was high. These data suggested species difference of relative gem-glu exposure between human and mice, as well as a net inductive DDI potential of gemfibrozil in mouse model. [ABSTRACT FROM AUTHOR]

Dark-field illumination is shown to make planar chiral nanoparticle arrangements exhibit circular dichroism in extinction, analogous to true chiral scatterers. Single oligomers, consisting rotationally symmetric arrangements of gold nanorods, are experimentally observed to exhibit circular dichrosim at their maximum scattering with strong agreement to numerical simulation. A dipole model is developed to show that this effect is caused by a difference in the projection of a nanorod onto the handed orientation of electric fields created by a circularly polarized dark-field normally incident on a glass-air interface. Owing to this geometric origin, the wavelength of the peak chiral response is experimentally shown to shift depending on the separation between nanoparticles. All presented oligomers have physical dimensions less than the operating wavelength, and the applicable extension to closely packed planar arrays of oligomers is demonstrated to amplify the magnitude of circular dichroism. This realization of strong chirality in these oligomers demonstrates a new path to engineer optical chirality from planar devices using dark-field illumination. [ABSTRACT FROM AUTHOR]

Background and Purpose: Fenofibrate, a PPARα agonist, is the most widely prescribed drug for treating hyperlipidaemia. Although fibrate drugs are reported to be beneficial for cholestasis, their underlying mechanism has not been determined.Experimental Approach: Wild-type mice and Pparα-null mice were pretreated orally with fenofibrate for 3 days, following which α-naphthylisothiocyanate (ANIT) was administered to induce cholestasis. The PPARα agonist WY14643 and JNK inhibitor SP600125 were used to determine the role of PPARα and the JNK pathway, respectively, in cholestatic liver injury. The same fenofibrate regimen was applied to investigate its beneficial effects on sclerosing cholangitis in a DDC-induced cholestatic model.Key Results: Fenofibrate, 25 mg·kg-1 twice a day, totally attenuated ANIT-induced cholestasis and liver injury as indicated by biochemical and histological analyses. This protection occurred in wild-type, but not in Pparα-null, mice. Alterations in bile acid synthesis and transport were found to be an adaptive response rather than a direct effect of fenofibrate. WY14643 attenuated ANIT-induced cholestasis and liver injury coincident with inhibition of JNK signalling. Although SP600125 did not affect cholestasis, it inhibited liver injury in the ANIT model when the dose of fenofibrate used was ineffective. Fenofibrate was also revealed to have a beneficial effect in the sclerosing cholangitis model.Conclusions and Implications: These data suggest that the protective effects of fenofibrate against cholestasis-induced hepatic injury are dependent on PPARα and fenofibrate dose, and are mediated through inhibition of JNK signalling. This mechanism of fenofibrate protection against intrahepatic cholestasis may offer additional therapeutic opportunities for cholestatic liver diseases. [ABSTRACT FROM AUTHOR]

Holography is of great interest for both scientific research and industry applications, but it has always suffered from the strong dependence on wavelength and polarization of the incident light. Having revisited the Huygens-Fresnel principle, we propose a novel holography mechanism by elaborately choosing discrete point sources (PSs) and realize it experimentally by mimicking the radiated fields of these PSs through carefully designed photon-nanosieves. Removing the modulation dispersion usually existing in traditional and metasurface holograms, our hologram empowers the simultaneous operation throughout the ultraviolet, entire visible and near-infrared wavelength regions without polarization dependence. Due to the deep-subwavelength dimension of nanosieves, this robust hologram offers a large angle-of-view of 40°×40° and possesses a lensing effect under a spherical-wave illumination, which can work as a high-resolution, lens-less and distortion-free microprojector that displays a 260× magnified image. It might open an avenue to a high-tolerance holographic technique for electromagnetic and acoustic waves. [ABSTRACT FROM AUTHOR]

Traditional detour-phase hologram is a powerful optical device for manipulating phase and amplitude of light, but it is usually not sensitive to the polarization of light. By introducing the light-metasurface interaction mechanism to the traditional detour phase hologram, we design a novel plasmonic nano-slits assisted polarization selective detour phase meta-hologram, which has attractive advantages of polarization multiplexing ability, broadband response, and ultra-compact size. The meta-hologram relies on the dislocations of plasmonic slits to achieve arbitrary phase distributions, showing strong polarization selectivity to incident light due to the plasmonic response of deep-subwavelength slits. To verify its polarization sensitive and broadband responses, we experimentally demonstrate two holographic patterns of an optical vortex and an Airy beam at p- and s-polarized light with wavelengths of 532nm, 633nm and 780nm, respectively. Furthermore, we realize an application example of the meta-hologram as a polarization multiplexed photonic device for multi-channel optical angular momentum (OAM) generation and detection. Such meta-holograms could find widespread applications in photonics, such as chip-level beam shaping and high-capacity OAM communication. [ABSTRACT FROM AUTHOR]

Much effort has been devoted to develop new porous structures for methane storage. We report a new porous coordination framework showing exceptional methane uptakes (e.g. 263 v/ v at 298 K and 65 bar) and adsorption enthalpies (21.6 kJ mol−1) as high as current record holders functionalized by open metal sites. Computational simulations demonstrated that the hierarchical pore structure consisting of single-wall nanocages has suitable sizes/shapes and organic binding sites to enforce not only strong host-methane and methane-methane interactions but also dense packing of methane molecules. [ABSTRACT FROM AUTHOR]

A dual-resonance surface-enhanced Raman scattering (SERS) chip which also serves as a localized surface plasmon resonance (LSPR) refractive index sensor is proposed. The dual-resonance SERS chip can simultaneously enhance excitation and Stokes lines for Raman signals detection in a broad wavelength region with virtually no limitation. Thus, it is especially useful for Raman detection at long wave numbers and hyper Raman. The great performance of this chip relies on the highly independent tunability of the two localized plasmonic resonances from the optical to the near-infrared region and the strict 'hot spot' match in space for both resonant wavelengths. Furthermore, Raman signals of poly-methyl-methacrylate (PMMA) from 500 cm−1 to 3300 cm−1 are measured in the experiments and an obvious superiority can be seen compared to a single-resonance SERS chip. In an addition, by using the subradiant magnetic dipole resonance, the LSPR refractive sensor gives a high sensitivity of 577 nm/RIU and high figure of merit (FoM) of 14.2. The experimental results are consistent with the simulated results. This dual-functional sensing chip opens a route for dual-modality detection of the concentration of some specific molecules. [ABSTRACT FROM AUTHOR]

A hydrated 5-azotriazolyl salicylic acid of [(H3ATSA)]⋅2 H2O ( 1) and its CdII complex of [Cd2(H2ATSA)4]⋅13 H2O ( 2) have been synthesized and characterized by single-crystal X-ray diffraction analysis and a neutral trans- Z-enol form of H3ATSA and another anionic trans- E-enol H2ATSA− isomer have been found in 1 and 2, respectively. The yellow crystal of 2 can be transformed in situ into red crystals in NaOH solution. The diffuse reflectance and photoluminescent spectra for the crystal powder samples and the aqueous solutions of 1 and 2 have been investigated. The DFT and TDDFT calculations at B3LYP/6-31G* level for 1 and B3LYP/Lanl2dz level for 2 have been used to demonstrate the characteristic absorption spectra and the trans-enol to cis-keto photo- and thermoisomeric reaction for the ATSA3− anion. The onion cell imaging taken by confocal laser scanning microscope was observed with 1 and 2 as fluorescent labels. [ABSTRACT FROM AUTHOR]

The article discusses the development of the user-friendly interface AtomSim intended for atomistic simulation of crystallographic materials. AtomSim is created using forcefield-based dynamics through physics engines like the General Utility Lattice Program and utilizes operating-system-independent Java with Swing components. The organization of the source code of the AtomSim is also described.

Cold atmospheric plasma has selective anticancer effects, while limited penetration depth and lifetime of reactive species restrict its usage. Herein, we adopt saline and hydrogel as carriers of plasma‐induced reactive species, and link reactive species accumulation, attenuation, storage, and slow‐release to anticancer effects of plasma‐activated media. Results reveal that plasma‐activated hydrogel (PAH) has a sustained anticancer effect and prolongs the storage duration of reactive species, thus causing more intracellular oxidative species accumulation and inducing melanoma cell apoptosis with reactive species continuously released to cell medium. In contrast, plasma‐activated saline has an attenuated anticancer effect with decline in reactive species. Therefore, PAH serves as a useful reactive species carrier and has potential for further anticancer research. [ABSTRACT FROM AUTHOR]

Polarization–phase interaction on the nanoscale is the cause of many unique effects that are absent or weak in traditional optics. These effects enable various applications in physics, nano‐optics, and material science. Here, by making use of a properly designed metasurface, polarization‐to‐phase coupling in a structured surface is investigated. The wavefront of a surface plasmon polariton (SPP), emitted from the metasurface, can be tuned continuously and linearly by changing the incident polarization along the longitudinal line at the Poincaré sphere. This type of phase modulation with polarization enables dynamic control of the wavefront. This is very different from other methods that achieve phase modulation through nano‐structures, which offer little room for tuning after the structure has been completed. As a demonstration of application, a plasmonic structured illumination microscope is achieved, where the near‐field standing‐wave of the SPP is controlled dynamically through the incident polarization. This improves both reliability and stability substantially. Metasurfaces are powerful tools to modulate the wavefront of an electromagnetic field. In combination with structured illumination microscopy (SIM) (the "Meta‐SIM"), this allows more degrees of freedom and should accelerate the progress of SIM technology. A kind of birefringent metasurface, composing of a pair of perpendicular nano‐hole arrays, enables dynamic control of the near‐field standing waves of surface plasmon polaritons with incident polarizations, which is employed in plasmonic structured illumination microscopy. [ABSTRACT FROM AUTHOR]

The title complex, [Cd(C(2)HN(9))(C(10)H(8)N(2))(2)]·0.5C(10)H(8)N(2)·H(2)O, was prepared under hydro-thermal reaction conditions. The asymmetric unit contains the cadmium complex, half a 2,2'-bipyridine solvent mol-ecule and a solvent water mol-ecule. The Cd(II) ion is coordinated by four N atoms from two 2,2'-bipyridine ligands and two N atoms from an HBTA(-) anion ligand [where H(2)BTA is N,N-bis-(1H-tetra-zol-5-yl)amine], forming an octa-hedral geometry. The complex is linked into a three-dimensional network by O-H⋯N and N-H⋯N hydrogen bonds and by the stacking inter-actions of rings, with distances of 3.5-3.7 Å between the atoms of two parallel 2,2'-bipyridine rings.