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An autocatalytic nanosystem with glucose depletion for triple synergetic cancer starvation therapy, cascade amplified hypoxia-activated chemotherapy and enhanced H2O2-dependent chemodynamic therapy.

Defects engineering is an effective strategy to promote electrocatalytic performance. Herein, cobalt binary chalcogenide hollow spheres (CBC HSs) with sulfur (S) defects were prepared by selenium (...

Multifunctional mesoporous silica-based nanocarriers able to efficiently encapsulate drugs for stimuli-responsive release and display rapid biodegradation are highly desirable. In this work, we dope disulfide bonds and calcium into silica framework by one step method to obtain a redox and pH dual-responsive biodegradable mesoporous silica nanoparticle (BT-Ca-MSN) as a potential drug carrier for synergistic cancer therapy. TEM and ICP-OES are used to assess the biodegradation behavior of BT-Ca-MSN. The results show that BT-Ca-MSN can significantly biodegrade in a concurrent reductive and acidic environment due to the simultaneous disulfide bonds cleavage and Ca2+ release. In addition, BT-Ca-MSN shows efficient drug loading capacity and significant biodegradation-mediated drug release. Moreover, the in-vitro cytotoxicity indicates that BT-Ca-MSN can not only exhibit significant cancer cell killing effect without obvious toxicity on healthy cells via the way of released Ca2+-mediated apoptosis, but also can combine with its loaded doxorubicin hydrochloride for synergistic cancer therapy. This work demonstrates that BT-Ca-MSN is a promising platform as drug carrier, providing a paradigm to rationally design biodegradable silica-based carriers for highly efficient cancer therapy.

Ameliorating the interfacial issues of the zinc anode, particularly dendrite growth and electrode corrosion, is imperative for rechargeable zinc metal batteries. Herein, an electrochemical-inert li...

Potassium-ion batteries (PIBs) hold great potential as an alternative to lithium-ion batteries due to the abundant reserves of potassium and similar redox potentials of K+/K and Li+/Li. Unfortunately, PIBs with carbonaceous electrodes present sluggish kinetics, resulting in unsatisfactory cycling stability and poor rate capability. Herein, we demonstrate that the synergistic effects of the enlarged interlayer spacing and enhanced capacitive behavior induced by the co-doping of nitrogen and sulfur atoms into a carbon structure (NSC) can improve its potassium storage capability. Based on the capacitive contribution calculations, electrochemical impedance spectroscopy, the galvanostatic intermittent titration technique, and density functional theory results, the NSC electrode is found to exhibit favorable electronic conductivity, enhanced capacitive adsorption behavior, and fast K+ ion diffusion kinetics. Additionally, a series of ex-situ characterizations demonstrate that NSC exhibits superior structural stability during the (de)potassiation process. As a result, NSC displays a high reversible capacity of 302.8 mAh g−1 at 0.1 A g−1 and a stable capacity of 105.2 mAh g−1 even at 2 A g−1 after 600 cycles. This work may offer new insight into the effects of the heteroatom doping of carbon materials on their potassium storage properties and facilitate their application in PIBs.

Sodium superionic conductor (NASICON)-type compounds have been regarded as promising cathodes for sodium-ion batteries (SIBs) due to their favorable ionic conductivity and robust structural stability. However, their high cost and relatively low energy density restrict their further practical application, which can be tailored by widening the operating voltages with earth-abundant elements such as Mn. Here, we propose a rational strategy of infusing Mn element in NASICON frameworks with sufficiently mobile sodium ions that enhances the redox voltage and ionic migration activity. The optimized structure of Na3.5Mn0.5V1.5(PO4)3/C is achieved and investigated systematically to be a durable cathode (76.6% capacity retention over 5,000 cycles at 20 C) for SIBs, which exhibits high reversible capacity (113.1 mAh·g−1 at 0.5 C) with relatively low volume change (7.6%). Importantly, its high-areal-loading and temperature-resistant sodium ion storage properties are evaluated, and the full-cell configuration is demonstrated. This work indicates that this Na3.5Mn0.5V1.5(PO4)3/C composite could be a promising cathode candidate for SIBs.

One-dimensional (1D) hybrid nanostructures composed of silver/silver sulfide (Ag/Ag2S) and zinc sulfide (ZnS) were prepared by controllable migration of Ag species from the Ag nanowire (NW) core in...

Poor tumor penetration is a major obstacle to nanomedicine for achieving effective anticancer therapy. Tumor microenvironment-induced nanomedicine size shrinkage is a promising strategy to overcome the drug penetration barrier across the dense tumor matrix. Herein, we design a size-shrinkable nanocarrier that uses acid as a means of triggering a change in particle size for co-achievement of efficient tumor accumulation followed by deep tumor penetration and rapid clearance from the body. This nanocarrier is constructed from a pH-sensitive lipid layer shell and an ultrasmall amino-functionalized mesoporous silica nanoparticle core capable of loading drugs. After intravenous injection into mice bearing the 4T1 tumor, the nanocarrier with an initial hydrodynamic size of about 33 nm could effectively accumulate at the tumor site through the enhanced permeability and retention effect. Subsequently, in the acidic tumor microenvironment, the lipid layer comprising 9 alkyl-spiropyran (SP-C9) undergoes a volume shrinkage due to the conversion of hydrophobic SP-C9 to amphiphilic 9 alkyl-merocyanine (MC-C9), thus leading to a significant decrease in the entire particle size (hydrodynamic size ∼17 nm) for enhanced intratumoral penetration. Moreover, we find that this size-shrinkable nanocarrier could be rapidly excreted out of the body based on the ICP analysis, significantly reducing biosafety issues. Benefiting from the effective tumor accumulation and penetration of the nanocarrier, the released doxorubicin shows potent antitumor efficacy. This demonstrates the high potential of the designed nanocarrier in solid tumor treatment.

The balance between tumor accumulation and renal clearance has severely limited the efficacy of mesoporous silica-based drug nanocarriers in cancer therapy. Herein, a pH-responsive dissociable mesoporous silica-based nanoplatform with efficient dual-drug co-delivery, tumor accumulation and rapid clearance for cancer therapy is achieved by adjusting the wetting of the mesoporous silica surface. At pH 7.4, the synthesized spiropyran- and fluorinated silane-modified ultrasmall mesoporous silica nanoparticles (SP-FS-USMSN) self-assemble to form larger nanoclusters (denoted as SP-FS-USMSN cluster) via hydrophobic interactions, which can effectively co-deliver anticancer drugs, doxorubicin hydrochloride (Dox) and curcumin (Cur), based on the mesopores within SP-FS-USMSN and the voids among the stacked SP-FS-USMSN. At pH 4.5-5.5, the conformational conversion of spiropyran from a "closed" state to an "open" state causes the wetting of the SP-FS-USMSN surface, leading to the dissociation of the SP-FS-USMSN cluster for drug release and renal clearance. The in vitro and in vivo studies demonstrate that the Cur and Dox co-loaded SP-FS-USMSN cluster (Cur-Dox/SP-FS-USMSN cluster) possesses great combined cytotoxicity, and can accumulate into tumor tissue by its large size-favored EPR effect and potently suppress tumor growth in HepG2-xenografted mice. This research demonstrates that the SP-FS-USMSN cluster may be a promising drug delivery system for cancer therapy and lays the foundation for practical mesoporous silica-based nanomedicine designs in the future.

The development of low-cost and high-safety zinc-ion batteries (ZIBs) has been extensively discussed and reviewed in recent years, but the work on the comprehensive discussion and perspectives in developing zinc-ion electrolytes is still relatively lacking. Faced with critical challenges and bottlenecks practically, the viability of ZIBs critically depends on the development of suitable electrolytes and their practical considerations. In this review, a systematic summary with regard to the basic characteristics of zinc-ion electrolytes facing different issues from optimization strategies to the fundamental science of electrolyte/electrode interfaces (EEIs), particularly in the feasible modifications and advanced characterizations of EEIs, has been put forward. Due to the lack of consideration of the practical issues in major academic studies, we have particularly highlighted aspects that mainly focus on the choice of the electrolyte system, dosage of liquid and fluid electrolytes, status of gel and all-solid electrolytes, together with other concerns related to the electrolytes. The final section proposes significant perspectives to guide and promote the development of zinc-ion electrolytes.

Lithium–sulfur batteries have received extensive attention owing to abundant sulfur resources and high energy density. However, their practical applications are hindered by the low utilization of sulfur due to its poor electronic conductivity, the shuttle effect and the sluggish redox kinetics of soluble lithium polysulfides (LiPSs), thus resulting in severe fading capacity. In study, graphene decorated with hetero-Co9S8–NiS sheets (BMS-G) was employed as a host material to support S in cathodes. The hetero-Co9S8–NiS effectively confined numerous LiPS species by chemisorption, and expedited the redox kinetics of LiPS. Consequently, the cathode with the BMS-G composite delivered high reversible specific capacities of 1142.9 mA h g−1 at 0.2 C and 705.8 mA h g−1 at 2 C, and had an excellent cycling stability (only 0.031% capacity fading per cycle over 800 cycles at 1 C was observed).

Silicon oxides (SiOx) are regarded as one of the most potential anode materials for lithium-ion batteries with the advantages of a high theoretical capacity, low discharge platform (

Lithium-ion batteries are a typical representative of energy storage system with high storage capacity and good cycle stability. However, the low specific capacity can not meet the storage capacity requirements for new generation of electronic products, which have limited their practical application. Herein, CoF 2 nanoparticles loaded on carbon fiber cloth (CoF 2 @CFC) as a flexible composite material prepared without binder or conductive agent is introduced as a cathode for lithium-ion batteries, which exhibit a high specific capacity of 330 mA h g −1 at 100 mA g −1 and have a stable specific capacity of 100 mA h g −1 at 1 A g −1 even after 1000 cycles. In addition, the flexibility of CoF 2 @CFC creates an application potential in the field of flexible electronic devices and wearable electronics.

High-capacity anode materials are widely studied for rechargeable batteries, which have the capability of storing more Li+ ions per formula. However, they normally experience large volume expansion and suffer inferior cycling stability. Herein, we propose pea-pod structured V2O3 yolk-shell microspheres@N, S co-doped carbon fiber network as an excellent anode material for lithium ion batteries. The prepared vanadium dioxide precursor is uniformly embedded into the carbon fibers by electrospinning treatment and further converted into V2O3 yolk-shell microspheres during the calcination process. The conductive carbon fiber framework which links V2O3 microspheres enhanced the electrical conductivity and structural stability significantly. Moreover, the co-doped N and S atoms derived from polymer could produce extrinsic defects, thereby improving Li+ diffusion and electrochemical active sites. When used as anodes for lithium ion batteries, the composite exhibits a high reversible capacity (793.7 mA h g−1 after 100 cycles at 100 mA g−1), excellent rate performance and cycle stability.

Germanium-based materials has been considered as a promising anode material for Li-ion batteries due to their high theoretical capacity. Herein, we reported a novel Ge/GeO 2 -Reduced graphene oxide (GG-RGO) microcubes via one-step recombination using sodium borohydride as reductant, followed by a calcination process in reducing atmosphere. During the recombination, the reduced graphene oxide coated GeO 2 nanoparticles self-assemble to form three-dimensional Ge shell/GeO 2 core cubic structure. RGO coated construction can relieve volume expansion, provide a large reactive area and reduce distance for lithium diffusion. Meanwhile, two-phase Ge/GeO 2 composite nanostructure can effectively increase specific capacity. Benefited from its unique three-dimensional structure, the Ge/GeO 2 -RGO composites exhibit high reversible capacity (1005 mAh g −1 at 100 mA g −1 ), good cycling stability (a high reversible capacity of 933 mAh g −1 after 50 cycles) and rate performance (740 mAh g −1 at 2000 mAh g −1 ).

Transition metal phosphides have been explored as promising active materials for sodium-ion batteries (SIBs) and hydrogen evolution reaction (HER) applications owing to their unique physical and chemical characteristics. However, they suffer from the drawbacks such as severe agglomeration, and sluggish reaction kinetics. Herein, bimetallic phosphides (Ni2P/ZnP4) embedded in P-doped carbon hierarchical microspheres are demonstrated with robust structural integrity, fast charge transfer, and abundant active sites. As expected, the optimally structured Ni2P/ZnP4 composite exhibits good electrochemical performance as an anode material in SIBs, including high specific capacity, good cycling stability and rate capability. Meanwhile, the Ni2P/ZnP4 composite also exhibits excellent electrocatalytic performance for HER with a small overpotential of 62 mV, a Tafel slope of 53 mV dec−1, as well as excellent stability.

Rechargeable aqueous zinc-ion batteries (ZIBs) with advantages of high safety and low-cost gradually show potential in large-scale energy storage/supply application. Yet the further development of aqueous ZIBs is hindered by finding suitable cathodes. Here we demonstrate that the chemical pre-intercalated transition metal ions (e.g. Fe2+, Co2+, Ni2+, Mn2+, Zn2+ and Cu2+, etc.) into the interlayer of V2O5, could effectively improve the electrochemical performance of aqueous ZIBs, in terms of high capacity, rate capability and long-term cycling stability, as well as excellent broad temperature adaptability. For instance, Cu2+-intercalated V2O5 cathode exhibits high capacity of 180 mA h g−1 after 10000 cycles at 10 A g−1 and 122 mA h g−1 after 3000 cycles at 20 A g−1. This universal strategy of pre-intercalated metal ions in the host materials is found to enable fast Zn2+ diffusion, enhanced electrical conductivity, and excellent structural reversibility, which can be applicable for other well-established aqueous ZIBs cathodes (i.e. MnO2), or other advanced battery systems.

Sodium-ion batteries (SIBs) have attracted considerable attention for large-scale energy storage systems as a promising alternative to lithium-ion batteries (LIBs) due to the huge availability and low-cost. Yet the development of SIBs has been hindered by the low reversibility, sluggish ion diffusion, as well as large volume variations. Herein, we report an efficient hydrothermal method for fabricating hierarchical porous Na3V2(PO4)3/C (NVP/C) microspheres assembled from interconnected nanoflakes. The NVP nanocrystals are uniformly wrapped by N-doped carbon layer. As a half-cell cathode, the NVP/C porous microspheres exhibit superior rate capability (99.3 mA h g−1 at 100 C) and excellent cyclic stability (79.1% capacity retention over 10,000 cycles at 20 C). A full-cell configuration coupled with NVP/C cathode and SnS/C fibers anode exhibits an estimated practical energy density of 223 W h kg−1. The superior performance can be ascribed to the hierarchical porous micro/nano structure along with N-doped carbon encapsulation, which provide bicontinuous electron/ion pathways, large electrode-electrolyte contact area, as well as robust structural integrity. This work provides a promising approach for boosting the electrochemical performance of battery materials via the integration of hierarchical structure and heteroatoms doped carbon coating.

Silicon is believed to be a promising anode material for lithium ion batteries because of its highest theoretical capacity and low discharge potential. However, severe pulverization and capacity fading caused by huge volume change during cycling limits its practical application. In this work, necklace-like N-doped carbon wrapped mesoporous Si nanofibers (NL-Si@C) network has been synthesized via electrospinning method followed by magnesiothermic reduction reaction process to suppress these issues. The mesoporous Si nanospheres are wrapped with N-doped carbon shells network to form yolk-shell structure. Interestingly, the distance of adjacent Si@C nanospheres can be controllably adjusted by different addition amounts of SiO2 nanospheres. When used as an anode material for lithium ion batteries, the NL-Si@C-0.5 exhibits best cycling stability and rate capability. The excellent electrochemical performances can be ascribed to the necklace-like network structure and N-doped carbon layers, which can ensure fast ions and electrons transportation, facilitate the electrolyte penetration and provide finite voids to allow large volume expansion of inner Si nanoparticles. Moreover, the protective carbon layers are also beneficial to the formation of stable solid electrolyte interface film.

Owing to their high cost and safety hazards, and the low abundance of Li in natural resources, the future of Li-ion batteries is becoming difficult. To replace Li-ion batteries, aqueous multivalent ion batteries are considered to be a worthwhile choice. In particular, aqueous zinc ion batteries are becoming an attractive option due to the natural abundance and unique properties of zinc. However, as for the Li-ion battery, the Zn-ion battery also has its own inadequacies in terms of cathodes. Finding a suitable cathode material for Zn-ion batteries with adequate structural stability and high capacity is an uphill task for researchers. This review presents the recent developments of various cathode materials in zinc ion batteries and their effectiveness towards the advancement of Zn-ion batteries. Based on the collected literature, various strategies adopted for enhancing the performance of Zn-ion batteries are also briefly discussed in this review. Furthermore, the explicit progress and future perspectives of Zn-ion batteries are also discussed.

Homogeneous copper incorporated nickel sulfide (NS) nanosheets were realized via an in situ ion exchange method and one-pot hydrothermal process. Nickel foam (NF) and copper foam (CF) were used as metal sources for the co-formation of Cu1.8S–Ni3S2 in the presence of thiourea. As a result of the Cu incorporation, the NF-supported Ni3S2 nanosheets exhibited improved electronic conductivity with higher electrochemical surface area (ECSA). When evaluated as electrode materials for supercapacitors, the as-obtained active materials demonstrated high specific capacitance (1686 F g−1 at 1 A g−1) with excellent cycling performance (95.39% capacitive retention after 10 000 cycles), which may be attributed to the unique structural features as well as the synergistic effect of localized copper species with Ni3S2 nanosheets.

We report the engineering of the interplanar spacing of ammonium vanadates to achieve the optimal electrochemical performance as cathodes for aqueous zinc-ion batteries (ZIBs) and provide insights into the origin of the enhanced electrochemical behaviors. The NH4V4O10 compound, with the largest interplanar spacing (9.8 A) and high diffusion coefficient, exhibits high energy density (374.3 W h kg−1) and power density (9000 W kg−1) as well as superior long-term cycling performance (a discharge capacity of 255.5 mA h g−1 can be maintained after 1000 cycles at 10 A g−1). With the merits of impressive energy density and long cycle life, the NH4V4O10 might be a new promising cathode for aqueous ZIBs for grid energy storage applications. This work provides a direction for choosing or designing the ideal high-performance cathode for aqueous ZIBs and other advanced battery systems.

Nb2O5 has attracted increasing attention as anode materials for lithium ion batteries (LIBs) because of its high safety and good structural stability. However, its electrochemical properties are controlled by the poor electronic conductivity and low ion diffusivity. In this work, we report the preparation of Nb2O5/carbon nanocomposites overcomes these issues by a facile solvothermal method with subsequent calcination. The Nb2O5 nanoparticles are homogeneously distributed in a carbon matrix derived from carbon quantum dots. As anode materials for lithium ion batteries, the as-prepared Nb2O5/carbon nanocomposites exhibit high capacity, good rate capability and cyclic stability. The Nb2O5/carbon nanocomposites can deliver a stable capacity of 385 mA h g−1 after 100 cycles at 0.1 A g−1. A specific capacity of 240 mA h g−1 is maintained even after 600 cycles at 1 A g−1. The composite electrode exhibits improved electrochemical performance than pure Nb2O5 electrode. With the homogeneous distribution of the Nb2O5 in a carbon matrix derived from carbon quantum dots, the aggregation of Nb2O5 during cycles can be prevented and the electronic conductivity of Nb2O5 can be enhanced.

Transition metal dichalcogenides (TMDs) have attracted increasing attention for rechargeable batteries because of its high theoretical capacity. However, its real application is limited by the intrinsic low electron conductivity and inferior structural stability. Herein, we report the fabrication of one-dimensional (1D) MoSe2/C nanorods composite from organic-inorganic hybrid Mo3O10(C2H10N2) (named as MoOx-EDA) with subsequent selenization and carbon coating process. As anode materials for lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs), the carbon-encapsulated composite exhibited enhanced Li+/Na+ storage properties compared to MoSe2 nanorods, including good cycling stability and high rate capability. A specific capacity of 835 mA h g−1 can be obtained at a current density of 200 mA g−1 for the MoSe2/C electrode in LIBs, which retained 755 mA h g−1 after 200 cycles. Moreover, a reversible Na+ storage capacity of 404 mA h g−1 can be remained after 100 cycles at a current density of 200 mA g−1. The good electrochemical performances of the MoSe2/C nanorod composites can be attributed to the bicontinuous electron/ion pathways, low charge transfer resistance, and robust structure stability.

Tin sulfides have attracted great attentions as sodium-batteries anode materials due to the remarkable high theoretical capacity, but their application is vastly limited by the poor rate capability and cycle stability. In this report, we constructed a double carbon-coated structure of carbon-coated tin (II) sulfide nanoflakes anchored on reduced graphene sheets (C@SnS-rGO) by a one-pot solvothermal synthesis with a subsequent annealing process. The carbon layer deposited on the surface of nanoflakes and the rGO sheet substrate combined into a framework which can enhance the electric conductivity and structural stability. Moreover, the carbon skeleton is doped with nitrogen and sulfur atoms which can increase the active sites and surface-capacitive effect of the as-prepared composite. As anode materials for sodium-ion batteries, the C@SnS-rGO composite electrode exhibits high capacity, good rate capability and cycling stability. The superior electrochemical performances are attributed to the improved electronic conductivity and good structural stability of the composite electrode.

Three-dimensional heterogeneous nanocomposites exhibit eminent cycling stability and rate capability as electrode materials for lithium-ion batteries. In this work, the composites of MoS2 nanosheets uniformly coated TiO2 nanowire arrays are fabricated by a glucose-assisted hydrothermal approach. The usage of glucose can be favorable to the uniform growth of MoS2 morphology. As anode materials for lithium ion batteries, the composites exhibit good specific capacity, cycling stability and rate capacity. The enhanced electrochemical properties are attributed to uniformity of composites since the uniform composites can effectively integrate the good cycling stability of TiO2 nanowire arrays and high capacity of MoS2 nanosheets. The gentle synthesis procedure and excellent electrochemical properties make TiO2 nanowire@MoS2 nanosheet arrays promising in high-performance lithium-ion batteries.