Ion transport in crystalline fast ionic conductors is a complex physical phenomenon. Certain ionic species (e.g., Ag+, Cu+, Li+, F–, O2–, H+) in a solid crystalline framework can move as fast as in liquids. This property, although only observed in a limited number of materials, is a key enabler for a broad range of technologies, including batteries, fuel cells, and sensors. However, the mechanisms of ion transport in the crystal lattice of fast ionic conductors are still not fully understood despite the substantial progress achieved in the last 40 years, partly because of the wide range of length and time scales involved in the complex migration processes of ions in solids. Without a comprehensive understanding of these ion transport mechanisms, the rational design of new fast ionic conductors is not possible. In this review, we cover classical and emerging characterization techniques (both experimental and computational) that can be used to investigate ion transport processes in bulk crystalline inorganic materials which exhibit predominant ion conduction (i.e., negligible electronic conductivity) with a primary focus on literature published after 2000 and critically assess their strengths and limitations. Together with an overview of recent understanding, we highlight the need for a combined experimental and computational approach to study ion transport in solids of desired time and length scales and for precise measurements of physical parameters related to ion transport.

A series of metal-free organic dyes bridged by anthracene-containing π-conjugations were designed and synthesized as new chromophores for the application of dye-sensitized solar cells (DSCs). Detailed investigations on the relationship between the dye structures, photophysical properties, electrochemical properties, and performances of DSCs are described. With the introduction of the anthracene moiety, together with a triple bond for the fine-tuning of molecular planar configurations and to broaden absorption spectra, the short-circuit photocurrent densities (J sc ) and open-circuit photovoltages (V oc ) of DSCs were improved to a large extent. The improvement of J sc is attributed to much broader absorption spectra of the dyes with the anthracene moiety. Electrochemical impedance spectroscopy (EIS) analysis reveals that the introduction of the anthracene moiety suppresses the charge recombination arising from electrons in TiO 2 films with I 3 ions in the electrolyte, thus improving V oc considerably. On the basis of optimized molecular structures and DSC test conditions, the dye TC501 shows a prominent solar energy conversion efficiency (η) up to 7.03% (J sc ) 12.96 mA • cm -2 , V OC ) 720 mV, ff ) 0.753) under simulated AM 1.5 irradiation (100 mW • cm -2 ).

The development of alternative strategies for the efficient treatment of subcutaneous abscesses that do not require the massive use of antibiotics and surgical intervention is urgently needed. Herein, a novel synergistic antibacterial strategy based on photodynamic (PDT) and NO gas therapy is reported, in which, a PDT‐driven NO controllable generation system (Ce6@Arg‐ADP) is developed with l‐Arg‐rich amphiphilic dendritic peptide (Arg‐ADP) as a carrier. This carrier not only displays superior bacterial association and biofilm penetration performance, but also acts as a versatile NO donor. Following efficient penetration into the interior of the biofilms, Ce6@Arg‐ADP can rapidly produce massive NO via utilizing the H2O2 generated during PDT to oxidize Arg‐ADP to NO and l‐citrulline, without affecting singlet oxygen (1O2) production. The combination of 1O2 and the reactive by‐products of NO offers notable synergistic antibacterial and biofilm eradication effects. Importantly, following efficient elimination of all bacteria from the abscess site, Arg‐ADP can further generate trace quantities of NO to facilitate the angiogenesis and epithelialization of the wound tissues, thereby notably promotes wound healing. Together, this study clearly suggests that Arg‐ADP is a versatile NO donor, and the combination of PDT and NO represents a promising strategy for the efficient treatment of subcutaneous abscesses.

Incorporating mixed ion is a frequently used strategy to stabilize black-phase formamidinum lead iodide perovskite for high-efficiency solar cells. However, these devices commonly suffer from photoinduced phase segregation and humidity instability. Herein, we find that the underlying reason is that the mixed halide perovskites generally fail to grow into homogenous and high-crystalline film, due to the multiple pathways of crystal nucleation originating from various intermediate phases in the film-forming process. Therefore, we design a multifunctional fluorinated additive, which restrains the complicated intermediate phases and promotes orientated crystallization of α-phase of perovskite. Furthermore, the additives in-situ polymerize during the perovskite film formation and form a hydrogen-bonded network to stabilize α-phase. Remarkably, the polymerized additives endow a strongly hydrophobic effect to the bare perovskite film against liquid water for 5 min. The unencapsulated devices achieve 24.10% efficiency and maintain >95% of the initial efficiency for 1000 h under continuous sunlight soaking and for 2000 h at air ambient of ~50% humid, respectively.

In recent years, with the emergence of various kinds of drug-resistant bacteria, existing antibiotics have become inefficient in killing these bacteria, and the formation of biofilms has further weakened the therapeutic effect. More problematically, the massive use and abuse of antibiotics have caused severe side effects. Thus, the development of ultra-efficient and safe antibacterial systems is urgently needed. Herein, a photodynamic therapy (PDT)-driven CO-controlled delivery system (Ce6&CO@FADP) is developed for synergistic antibacterial and ablation biofilms. Ce6&CO@FADP is constructed using a fluorinated amphiphilic dendritic peptide (FADP) and physically loaded with Ce6 and CORM-401. After efficiently entering the bacteria, Ce6&CO@FADP can rapidly release CO intracellularly by the massive consumption of the H2O2 generated during the PDT process, without affecting the generation of singlet oxygen (1O2). As such, the combination of CO and 1O2 exerts notable synergistic antibacterial and biofilm ablation effects both in vitro and in vivo (including subcutaneous bacterial infection and biofilm catheter models) experiments. More importantly, all biosafety assessments suggest the good biocompatibility of Ce6&CO@FADP. Together, these results reveal that Ce6&CO@FADP is an efficient and safe antibacterial system, which has essential application prospects for the treatment of bacterial infections and ablation of biofilms in vivo.

Four metal-free organic sensitizers (TC101−TC104) with triple bonds in π-spacers and five reference dyes (TC, TC105, TPC1, D5, and TH208) without triple bonds were applied in dye-sensitized solar cells to study the influence of triple bonds as π-spacer units on their photoelectrochemical properties and dye-sensitized solar cells (DSCs) performance. Results show that the introduction of triple bond could red-shift the dye’s absorption spectrum due to the enhancement of the π-spacer. However, the spectrum red-shift is much less than that of the introduction of double bond because of more electronegativity of triple bond. The incident photon-to-current conversion efficiency reveals that the electron transfer yield (Φ(ν)ET) of DSCs becomes larger with the introduction of triple bond. Electrochemical impedance spectroscopy analysis reveals that the introduction of triple bond almost does not change the electron lifetimes in TiO2 films but decreases the effective diffusion lengths.

No abstract

No abstract