As a conceptually new class of two-dimensional (2D) materials, the ultrathin nanosheets as inorganic graphene analogues (IGAs) play an increasingly vital role in the new-generation electronics. However, the relatively low electrical conductivity of inorganic ultrathin nanosheets in current stage significantly hampered their conducting electrode applications in constructing nanodevices. We developed the unprecedentedly high electrical conductivity in inorganic ultrathin nanosheets. The hydric titanium disulfide (HTS) ultrathin nanosheets, as a new IGAs, exhibit the exclusively high electrical conductivity of 6.76 × 10(4) S/m at room temperature, which is superior to indium tin oxide (1.9 × 10(4) S/m), recording the best value in the solution assembled 2D thin films of both graphene (5.5 × 10(4) S/m) and inorganic graphene analogues (5.0 × 10(2) S/m). The modified hydrogen on S-Ti-S layers contributes additional electrons to the TiS2 layered frameworks, rendering the controllable electrical conductivity as well as the electron concentrations. Together with synergic advantages of the excellent mechanical flexibility, high stability, and stamp-transferrable properties, the HTS thin films show promising capability for being the next generation conducting electrode material in the nanodevice fields.

Ferromagnetism is usually deemed incompatible with superconductivity. Consequently, the coexistence of superconductivity and ferromagnetism is usually observed only in elegantly designed multi-ingredient structures in which the two competing electronic states originate from separate structural components. Here we report the use of surface molecular adsorption to induce ferromagnetism in two-dimensional superconducting NbSe2, representing the freestanding case of the coexistence of superconductivity and ferromagnetism in one two-dimensional nanomaterial. Surface-structural modulation of the ultrathin superconducting NbSe2 by polar reductive hydrazine molecules triggers a slight elongation of the covalent Nb–Se bond, which weakens the covalent interaction and enhances the ionicity of the tetravalent Nb with unpaired electrons, yielding ferromagnetic ordering. The induced ferromagnetic momentum couples with conduction electrons generating unique correlated effects of intrinsic negative magnetoresistance and the Kondo effect. We anticipate that the surface molecular adsorption will be a powerful tool to regulate spin ordering in the two-dimensional paradigm.

Photodynamical therapy (PDT), as an emerging treatment modality, which takes advantage of reactive oxygen species (ROS) initiated by light illumination to ablate tumor, has suffered from the limited treatment depth,...

Visualizing and dynamic tracking lipid droplets (LDs) are of great importance to biological research. Herein, two-photon absorption fluorescent small bioprobes based on lipophilic coumarin were developed, which exhibited high selectivity toward LDs in HeLa cells. Because of good biocompatibility and excellent photostability, the probes were applied to realize specific super-resolution visualization of the intracellular LDs in HeLa cells, offering us the quantitative results of the amount and diameters of LDs as well. Furthermore, the bioprobes were capable of monitoring the movements of the LDs in real time. We believe that bioprobes would provide new avenues to designing bioimaging and biological diagnosis.

Photodynamic therapy (PDT) takes advantage of reactive oxygen species (ROS) to trigger the apoptosis for cancer therapy. Given that cell apoptosis is a form of programmed cell death involved with multiple suborganelles and cancer cells are more sensitive to ROS than normal cells, early confirmation of the apoptosis induced by ROS would effectively avoid overtreatment. Herein, we highlight an aggregation-induced emission (AIE)-based theranostic agent (TPA3) to in situ dynamically track mitophagy prior to late apoptosis. TPA3 showed high specificity to autophagy vacuoles (AVs), of which appearance is the signature event of mitophagy during early apoptosis and delivered photocytotoxicity to cancer cells and skin cancer tumors in nude mice under irradiation of white light. Furthermore, in situ monitoring of the dynamical mitophagy process involved with mitochondria, AVs, and lysosomes was performed for the first time under confocal microscopy, providing a real-time self-monitoring system for assessing the curative effect prior to late apoptosis. This fluorescence imaging guided PDT witness great advances for applying in the clinical application.

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The direct urea fuel cell (DUFC) is an important but challenging renewable energy production technology,i to ffers great promise for energy-sustainable developments and mitigating water contamination. However,DUFCs still suffer from the sluggish kinetics of the urea oxidation reaction (UOR) owingtoa6e À transfer process,which poses asevere hindrance to their practical use.Herein, taking b-Ni(OH) 2 nanosheets as the proof-of-concept study,wedemonstrated asurface-chemistry strategy to achieve metallic Ni(OH) 2 nanosheets by engineering their electronic structure,r epresenting af irst metallic configuration of transition-metal hydroxides.S urface sulfur incorporation successfully brings synergetic effects of more exposed active sites,good wetting behavior,and effective electron transport, giving rise to greatly enhanced performance for UOR. Metallic nanosheets exhibited amuchhigher current density,smaller onset potential and stronger durability.Driven by growing concerns about global warming and the depletion of fossil fuel, developing renewable energy-production and -storage technologies represent an important but challenging issue. [1][2][3] In this regard, direct urea fuel cells offer great promise for energy-sustainable developments and also mitigating water contamination. [4][5][6] Theu rea fuel cell is designed based on 2CO(NH 2 ) 2 + 3O 2 !2N 2 + 4H 2 O + 2CO 2 , accomplishing power output and concurrently remedying urea-rich wastewater before urea naturally hydrolyzes in the environment. Compared to cathodic oxygen reduction reaction (ORR), the anodic urea oxidation reaction (denoted as UOR, CO(NH 2 ) 2 + 6OH À !N 2 + 5H 2 O + CO 2 + 6e À )undergoes more sluggish kinetics owing to a6e À transfer process and requires the use of electrocatalysts for promoting the reaction rate.T herefore,h igh-performance UOR catalysts are required to reduce the overpotential to drive the sluggish reaction. Although tremendous efforts have been devoted to pursue efficient electrocatalysts to give superior UOR performance, [7][8][9][10][11][12][13][14][15] they still suffer from inferior electrical conductivity and "poisoning", greatly hindering electrochemical efficiency for practical application.Conductive two-dimensional (2D) nanosheets have been explored for high-performance electrocatalysts because of their highly exposed catalytic surface and excellent electron transportation. Tw o-dimensional nanomaterials usually possess exposed surfaces with low-coordinated steps,e dges,a nd kinks,w hich provide abundant active sites to mediate the electrocatalytic process,allowing them to be efficient electrocatalysts. [16] Owing to the dimensionally reduced structure of 2D nanomaterials,i nw hich most of atoms are exposed on surface and thus offer high chemical activity,v arious strategies directed at the surface atoms,including defect engineering, surface incorporation and structural distortion, [17][18][19] have been employed to effectively augment the number of active sites.Moreover,intrinsic high conductivity is also essential fo...

Hydrazine electro-oxidation has received substantial attention owing to its high energy density, low onset potential, and wide applications in hydrazine-assisted hydrogen production and direct hydrazine fuel cells. In this work, crystalline cobalt/ amorphous LaCoO x hybrid nanoparticles embedded in porous nitrogen-doped carbon (N-C) were fabricated via pyrolytic decomposition of the dual-metal lanthanum-incorporated zeolitic imidazolate framework (La/ZIF-67), which exhibit high activity and stability toward the electrocatalytic hydrazine oxidation reaction (HzOR). The hybrid nanoparticles based on metallic cobalt and amorphous LaCoO x could provide abundant active sites for HzOR catalysis, while the highly conductive and porous N-C could act as both robust skeleton for anchoring the active hybrid nanoparticles and facile charge transport pathway for the HzOR process, thereby resulting in enhanced HzOR activity. With the synergistic merits of enriched active sites, a large surface area, enhanced charge-transfer ability, and intimate catalyst anchoring, promoted HzOR performance with high activity and stability was achieved for the optimized catalyst, which shows an ultralow onset potential of −0.17 V versus reversible hydrogen electrode (RHE), high HzOR current density of 69.2 mA cm −2 at 0.3 V versus RHE, and superior stability for 20 h continuous catalysis, making the catalyst a promising electrode material for hydrazine-assisted hydrogen production.