Latest ArticlesMesoporous silica nanoparticles (MSNs) are thought to be an attractive drug delivery material because of their advantages including high specific surface area, tunable pore size and morphology, easy surface modification and good biocompatibility. However, as a result of the poor biodegradability of MSNs, their biomedical applications are limited. To break the bottleneck of limited biomedical applications of MSNs, more and more researchers tend to design biodegradable MSNs (b-MSNs) nanosystems to obtain biodegradable as well as safe and reliable drug delivery carriers. In this review, we focused on summarizing strategies to improve the degradability of MSNs and innovatively proposed a series of advantages of b-MSNs, including controlled cargo release behavior, multifunctional frameworks, nano-catalysis, bio-imaging capabilities and enhanced therapeutic effects. Based on these advantages, we have innovatively summarized the applications of b-MSNs for enhanced tumor theranostics, including enhanced chemotherapy, delivery of nanosensitizers, gas molecules and biomacromolecules, initiation of immune response, synergistic therapies and image-guided tumor diagnostics. Finally, the challenges and further clinical translation potential of nanosystems based on b-MSNs are fully discussed and prospected. We believe that such b-MSNs delivery carriers will provide a timely reference for further applications in tumor theranostics.
As a kind of emerging energy storage devices, Aqueous zinc ion batteries possess the characteristics of safety, low cost and environmental friendliness. However, their further application is restricted by the sluggish electrochemical reaction kinetics and low conductivity. In this work, we prepare two H3.78V6O13 electrode materials with many active sites, which promotes the kinetics of ion diffusion and then improves the capacity of the cell. The as-obtained HVO-PVP electrode possess a capacity of 393.2 and 285.9 mAh/g at 0.2 and 5.0 A/g, respectively. Moreover, the assembled Zn//HVO-PVP cells also indicate excellent specific capacity and cycle stability at different operating temperatures (0–60 ℃).
For realizing the goals of “carbon peak” and “carbon neutrality”, lithium-ion batteries (LIB) with LiFePO4 as the cathode material have been widely applied. However, this has also led to a large number of spent lithium-ion batteries, and the safe disposal of spent lithium-ion batteries is an urgent issue. Currently, the main reason for the capacity decay of LiFePO4 materials is the Li deficiency and the formation of the Fe3+ phase. In order to address this issue, we performed high-temperature calcination of the discarded lithium iron phosphate cathode material in a carbon dioxide environment to reduce or partially remove the carbon coating on its surface. Subsequently, mechanical grinding was conducted to ensure thorough mixing of the lithium source with the discarded lithium iron phosphate. The reaction between CO2 and the carbon coating produced a reducing atmosphere, reducing Fe3+ to Fe2+ and thereby reducing the content of Fe3+. The Fe3+ content in the repaired LiFePO4 material is reduced. The crystal structure of spent LiFePO4 cathode materials was repaired more completely compare with the traditional pretreatment method, and the repaired LiFePO4 material shows good electrochemical performance and cycling stability. Under 0.1 C conditions, the initial capacity can reach 149.1 mAh/g. It can be reintroduced for commercial use.
Sulfide solid electrolytes with an ultrahigh ionic conductivity are considered to be extremely promising alternatives to liquid electrolytes for next-generation lithium batteries. However, it is difficult to obtain a thin solid electrolyte layer with good mechanical properties due to the weak binding ability between their powder particles, which seriously limits the actual energy density of sulfide all-solid-state lithium batteries (ASSLBs). Fortunately, the preparation of sulfide-polymer composite solid electrolyte (SPCSE) membranes by introducing polymer effectively reduces the thickness of solid electrolytes and guarantees high mechanical properties. In this review, recent progress of SPCSE membranes for ASSLBs is summarized. The classification of components in SPCSE membranes is first introduced briefly. Then, the preparation methods of SPCSE membranes are categorized according to process characteristics, in which the challenges of different methods and their corresponding solutions are carefully reviewed. The energy densities of the full battery composed of SPCSE membranes are further given whenever available to help understanding the device-level performance. Finally, we discuss the potential challenges and research opportunities for SPCSE membranes to guide the future development of high-performance sulfide ASSLBs.
In the practical operations of the sodium ion (Na+) batteries (SIBs), the fast transport of Na+ is desired for the rate performance, because the other ions in an electrolyte are electrochemically inert. In this study, we use molecular dynamics simulations to investigate the partial conductivity of Na+ (σNa+) in the salt-in-ionic liquid electrolytes (SILEs) composed of 1-ethyl-3-methylimidazolium (EMIM+) and bis(fluorosulfonyl)imide (FSI−) with various molar fraction of NaFSI. The simulations show that while the ionic conductivity of the SILE decreases monotonically with the increase of salt fraction of NaFSI, σNa+ peaks in the SILE with 0.5 molar fraction of NaFSI. Detailed analyses indicate that with the increase of salt fraction, the coordination structure of FSI− around Na+ changed from bidentate manner to monodentate manner which weakens the binding of FSI− to Na+. The effects are two folds. On one hand, the increased monodentate coordinations cause a large aggregate that hinders the transport of Na+ within the aggregate; on the other hand, the large aggregate captures most FSI− to form percolating ion network, and thus leaves a small portion of Na+’s that are not in the large aggregate to be more "free" to transport in the SILE.
Protein glycosylation and phosphorylation, as two of the most important protein post-translational modifications (PTMs), play key roles in living organisms. However, glycopeptides and phosphopeptides have low abundance in biological samples. In addition, the low ionization efficiency and the severe signal interference in the presence of other peptides present great difficulties for their direct mass spectrometry (MS) analysis. Therefore, it is important to develop feasible enrichment strategies to pretreat glycopeptides and phosphopeptides in complex samples before MS detection. This paper reviews the application of various magnetic nanomaterials (MNMs) in glycopeptides and phosphopeptides in the last decade, with emphasis on the enrichment principles, the design and synthesis process of the materials, and the effectiveness of the application in biological samples. In addition, possible future trends and potential challenges are presented.
The sluggish reaction kinetics of the oxygen evolution reaction (OER) and methanol oxidation reaction (MOR) remain obstacles to the commercial promotion of water splitting and direct methanol fuel cells. Considering the vital role of noble metals in electrocatalytic activity, this work focuses on the rational synthesis of Ni-noble metal composite nanocatalysts for overcoming the drawbacks of high cost and susceptible oxidized surfaces of noble metals. The inherent catalytic activity is improved by the altered electronic structure and effective active sites of the catalyst induced by the size effect of noble metal clusters. In particular, a series of Ni-noble metal nanocomposites are successfully synthesized by partially introducing noble metal into Ni with porous interfacial defects derived from Ni-Al layered double hydroxide (LDH). The Ni10Pd1 nanocomposite exhibits high OER catalytic activity with an overpotential of 0.279 V at 10 mA/cm2, surpassing Ni10Ag1 and Ni10Au1 counterparts. Furthermore, the average diameter of Pd clusters gradually increases from 5.57 nm to 44.44 nm with the increased proportion of doped Pd, leading to the passivation of catalytic activity due to the exacerbated surface oxidation of Pd in the form of Pd2+. After optimization, Ni10Pd1 delivers significantly enhanced OER and MOR electroactivities and long-term stability compared to that of Ni2Pd1, Ni1Pd1 and Ni1Pd2, which is conducive to the effective utilization of Pd and alleviation of surface oxidation.
The excited state dynamics and critically regulated factors of reverse intersystem crossing (RISC) in through-space charge transfer (TSCT) molecules have received insufficient attention. Here, five molecules of through space/bond charge transfer inducing thermally activated delayed fluorescence (TADF) are prepared, and their excited state charge transfer processes are studied by ultrafast transient absorption and theoretical calculations. DM-Z has a larger ∆EST, leading to a longer lifetime of intersystem crossing (ISC), resulting in the lowest photoluminescence quantum yield (PLQY). Oppositely, ISC and RISC are demonstrated to take place with shorter lifetimes for TSCT molecules. The face-to-face π-π stacking interactions and electron communication enable DM-B and DM-BX to have an efficient RISC, increasing the weight coefficient of RISC from 1.7% (DM-X) to close to 50% (DM-B and DM-BX) in the solvents, which make DM-BX and DM-B to have a high PLQY. However, partial local excitation in the donor center is observed and the charge transfer is decreased for DM-G and DM-X. The triplet excited state (DM-G) or singlet excited state (DM-X) mainly undergoes inactivation through a non-radiative relaxation process, resulting in less RISC and low PLQY. This work provides theoretical hints to enhance the RISC process in the TADF materials.