Developing Type‐I photosensitizers is considered as an efficient approach to overcome the deficiency of traditional photodynamic therapy (PDT) for hypoxic tumors. However, it remains a challenge to ...design photosensitizers for generating reactive oxygen species by the Type‐I process. Herein, we report a series of α,β‐linked BODIPY dimers and a trimer that exclusively generate superoxide radical (O2−.) by the Type‐I process upon light irradiation. The triplet formation originates from an effective excited‐state relaxation from the initially populated singlet (S1) to triplet (T1) states via an intermediate triplet (T2) state. The low reduction potential and ultralong lifetime of the T1 state facilitate the efficient generation of O2−. by inter‐molecular charge transfer to molecular oxygen. The energy gap of T1‐S0 is smaller than that between 3O2 and 1O2 thereby precluding the generation of singlet oxygen by the Type‐II process. The trimer exhibits superior PDT performance under the hypoxic environment.
Heavy‐atom‐free boron dipyrromethene (BODIPY)‐based photosensitizers generate ROS exclusively by the Type‐I process upon near‐infrared light illumination for tumor ablation.
For the first time, multinuclear noble‐metal clusters have been successfully stabilized by Ti‐oxo clusters. Two unprecedented Ag6@Ti16‐oxo nanoclusters with precise atomic structures were prepared ...and characterized. The octahedral Ag6 core has strong Ag−Ag bonds (ca. 2.7 Å), and is further stabilized by direct Ag−O−Ti coordination interactions. Moreover, as a result of different acidic/redox conditions in synthesis, the Ag6 core can adopt diverse geometric configurations inside the Ti16‐O shell. Correspondingly, structural differences greatly influence their optical limiting effects. The transmittance reduction activity of the clusters towards 532 nm laser shows a nearly linear concentration dependence, and can be optimized up to about 43 %. This work not only opens a new direction for multimetallic semiconductive nanoclusters with interesting optical properties, but also provides molecular models for important noble‐metal/TiO2 heterogeneous materials.
Silver core: Two Ag6@Ti16‐oxo nanoclusters with atomic core–shell structures show optical limiting effects towards 532 nm laser. The differences between the two clusters lie in the orientation of the Ag6 cluster inside the semiconductive Ti−O shell. This orientation influences the optical properties of the nanoclusters.
Electronic skin sensing devices are an emerging technology and have substantial demand in vast practical fields including wearable sensing, robotics, and user‐interactive interfaces. In order to ...imitate or even outperform the capabilities of natural skin, the keen exploration of materials, device structures, and new functions is desired. However, the very high resistance and the inadequate current switching and sensitivity of reported electronic skins hinder to further develop and explore the promising uses of the emerging sensing devices. Here, a novel resistive cloth‐based skin‐like sensor device is reported that possesses unprecedented features including ultrahigh current‐switching behavior of ≈107 and giant high sensitivity of 1.04 × 104–6.57 × 106 kPa−1 in a low‐pressure region of <3 kPa. Notably, both superior features can be achieved by a very low working voltage of 0.1 V. Taking these remarkable traits, the device not only exhibits excellent sensing abilities to various mechanical forces, meeting various applications required for skin‐like sensors, but also demonstrates a unique competence to facile integration with other functional devices for various purposes with ultrasensitive capabilities. Therefore, the new methodologies presented here enable to greatly enlarge and advance the development of versatile electronic skin applications.
A newly designed cloth‐based resistive electronic skin features ultrahigh current switching of ≈107 and extremely high sensitivity of 1.04 × 104–6.57 × 106 kPa–1 at pressures <3 kPa. And, notably, both features are achieved by a very low working voltage of 0.1 V. Taking these traits, our devices not only function as ultrasensitive sensors but can also be integrated with various functional components for multipurpose uses.
Designing highly conducting metal-organic frameworks (MOFs) is currently a subject of great interest for their potential applications in diverse areas encompassing energy storage and generation. ...Herein, a strategic design in which a metal-sulfur plane is integrated within a MOF to achieve high electrical conductivity, is successfully demonstrated. The MOF {Cu
(6-Hmna)(6-mn)·NH
}
(1, 6-Hmna = 6-mercaptonicotinic acid, 6-mn = 6-mercaptonicotinate), consisting of a two dimensional (-Cu-S-)
plane, is synthesized from the reaction of Cu(NO
)
, and 6,6'-dithiodinicotinic acid via the in situ cleavage of an S-S bond under hydrothermal conditions. A single crystal of the MOF is found to have a low activation energy (6 meV), small bandgap (1.34 eV) and a highest electrical conductivity (10.96 S cm
) among MOFs for single crystal measurements. This approach provides an ideal roadmap for producing highly conductive MOFs with great potential for applications in batteries, thermoelectric, supercapacitors and related areas.
Supported single‐atom catalysts have been emerging as promising materials in a variety of energy catalysis applications. However, studying the role of metal–support interactions at the molecular ...level remains a major challenge, primarily due to the lack of precise atomic structures. In this work, by replacing the frequently used TiO2 support with its molecular analogue, titanium‐oxo cluster (TOC), we successfully produced a new kind of Ti‐O material doped with single silver sites. The as‐obtained Ag10Ti28 cluster, containing four exposed and six embedded Ag sites, is the largest noble‐metal‐doped Ti‐O cluster reported to date. Density functional theory (DFT) calculations show that the Ag10Ti28 core exhibits properties distinct from those of metallic Ag‐based materials. This Ti‐O material doped with single Ag sites presents a high ϵd and moderate CO binding capacity comparable to that of metallic Cu‐based catalysts, suggesting that it might display different catalytic performance from the common Ag‐based catalysts, for example, for CO2 reduction. These results prove that the synergism of active surface metal atoms and the Ti‐O cluster support result in unique physical properties, which might open a new direction for single‐atom‐included catalysts.
Advantageous conjunction: The largest noble‐metal‐doped Ti‐O cluster, Ag10Ti28‐oxo, contains single silver sites. The synergism between the active surface metal atom and the Ti‐O cluster support produces unique electronic properties that are distinct from those of metallic Ag‐based materials.
A code is said to be an <inline-formula> <tex-math notation="LaTeX">r </tex-math></inline-formula>-local locally repairable code (LRC) if each of its coordinates can be repaired by accessing at most ...<inline-formula> <tex-math notation="LaTeX">r </tex-math></inline-formula> other coordinates. When some of the <inline-formula> <tex-math notation="LaTeX">r </tex-math></inline-formula> coordinates are also erased, the <inline-formula> <tex-math notation="LaTeX">r </tex-math></inline-formula>-local LRC cannot accomplish the local repair, which leads to the concept of <inline-formula> <tex-math notation="LaTeX">(r,\delta) </tex-math></inline-formula>-locality. A <inline-formula> <tex-math notation="LaTeX">q </tex-math></inline-formula>-ary <inline-formula> <tex-math notation="LaTeX">n, k </tex-math></inline-formula> linear code <inline-formula> <tex-math notation="LaTeX">\mathcal {C} </tex-math></inline-formula> is said to have <inline-formula> <tex-math notation="LaTeX">(r, \delta) </tex-math></inline-formula>-locality (<inline-formula> <tex-math notation="LaTeX">\delta \ge 2 </tex-math></inline-formula>) if for each coordinate <inline-formula> <tex-math notation="LaTeX">i </tex-math></inline-formula>, there exists a punctured subcode of <inline-formula> <tex-math notation="LaTeX">\mathcal {C} </tex-math></inline-formula> with support containing <inline-formula> <tex-math notation="LaTeX">i </tex-math></inline-formula>, whose length is at most <inline-formula> <tex-math notation="LaTeX">r + \delta - 1 </tex-math></inline-formula>, and whose minimum distance is at least <inline-formula> <tex-math notation="LaTeX">\delta </tex-math></inline-formula>. The <inline-formula> <tex-math notation="LaTeX">(r, \delta) </tex-math></inline-formula>-LRC can tolerate <inline-formula> <tex-math notation="LaTeX">\delta -1 </tex-math></inline-formula> erasures in every local code (i.e., punctured subcode), which degenerates to an <inline-formula> <tex-math notation="LaTeX">r </tex-math></inline-formula>-local LRC when <inline-formula> <tex-math notation="LaTeX">\delta =2 </tex-math></inline-formula>. A <inline-formula> <tex-math notation="LaTeX">q </tex-math></inline-formula>-ary <inline-formula> <tex-math notation="LaTeX">(r,\delta) </tex-math></inline-formula> LRC is called optimal if it meets the singleton-like bound for <inline-formula> <tex-math notation="LaTeX">(r,\delta) </tex-math></inline-formula>-LRCs. A class of optimal <inline-formula> <tex-math notation="LaTeX">q </tex-math></inline-formula>-ary cyclic <inline-formula> <tex-math notation="LaTeX">r </tex-math></inline-formula>-local LRCs with lengths <inline-formula> <tex-math notation="LaTeX">n\mid q-1 </tex-math></inline-formula> were constructed by Tamo, Barg, Goparaju, and Calderbank based on the <inline-formula> <tex-math notation="LaTeX">q </tex-math></inline-formula>-ary Reed-Solomon codes. In this paper, we construct a class of optimal <inline-formula> <tex-math notation="LaTeX">q </tex-math></inline-formula>-ary cyclic <inline-formula> <tex-math notation="LaTeX">(r,\delta) </tex-math></inline-formula>-LRCs (<inline-formula> <tex-math notation="LaTeX">\delta \ge 2 </tex-math></inline-formula>) with length <inline-formula> <tex-math notation="LaTeX">n\mid q-1 </tex-math></inline-formula>, which generalizes the results of Tamo et al. Moreover, we construct a new class of optimal <inline-formula> <tex-math notation="LaTeX">q </tex-math></inline-formula>-ary cyclic <inline-formula> <tex-math notation="LaTeX">r </tex-math></inline-formula>-local LRCs with lengths <inline-formula> <tex-math notation="LaTeX">n\mid q+1 </tex-math></inline-formula> and a new class of optimal <inline-formula> <tex-math notation="LaTeX">q </tex-math></inline-formula>-ary cyclic <inline-formula> <tex-math notation="LaTeX">(r,\delta) </tex-math></inline-formula>-LRCs (<inline-formula> <tex-math notation="LaTeX">\delta \ge 2 </tex-math></inline-formula>) with lengths <inline-formula> <tex-math notation="LaTeX">n\mid q+1 </tex-math></inline-formula>. The constructed optimal LRCs with length <inline-formula> <tex-math notation="LaTeX">n=q+1 </tex-math></inline-formula> have the best-known length for a given finite field with size <inline-formula> <tex-math notation="LaTeX">q </tex-math></inline-formula> when the minimum distance is larger than 4.
Lead halide perovskite-structured solar cells (PSCs) have drawn great attention due to a rapid improvement in their photoelectric conversion efficiency in recent years. In this study, we have ...enhanced photovoltaic performance by using mesoscopic zinc-doped TiO2 (meso-Zn:TiO2) as the electron extraction layer. Zn:TiO2 nanoparticles (Zn:TiO2 NPs) with various zinc doping levels were synthesized by combining sol–gel and hydrothermal methods. The synthesized Zn:TiO2 NPs were used to fabricate electron extraction layers by a screen-printing method. We systematically investigated the surface morphology, crystal structure, contact angle, charge carrier dynamics, electron mobility, and electrical conductivity of various meso-Zn:TiO2. Furthermore, photo-assisted Kelvin probe force microscopy (KPFM) was used to analyze the surface potential of perovskite films coated with various meso-Zn:TiO2 to understand the electron extraction behavior under the illumination of light at various wavelengths. Moreover, the energy levels of various meso-Zn:TiO2 were estimated by ultraviolet photoelectron spectroscopy (UPS) and UV-vis absorption spectroscopy. We discovered that the 5.0 mol% meso-Zn:TiO2 exhibited the optimal band alignment with perovskite. Finally, the average power conversion efficiency (PCE) of PSCs with meso-Zn:TiO2 was enhanced from 13.1 to 16.8%, and such fabricated PSC yielded a champion PCE of 18.3%.
Although numerous adsorbent materials have been reported for the capture of radioactive iodine, there is still demand for new absorbents that are economically viable and can be prepared by reliable ...synthetic protocols. Herein, we report a coordination‐driven self‐assembly strategy towards adsorbents for the sequential confinement of iodine molecules. These adsorbents are versatile heterometallic frameworks constructed from aluminum molecular rings of varying size, flexible copper ions, and conjugated carboxylate ligands. Additionally, these materials can quickly remove iodine from cyclohexane solutions with a high removal rate (98.8 %) and considerable loading capacity (555.06 mg g−1). These heterometallic frameworks provided distinct pore sizes and binding sites for iodine molecules, and the sequential confinement of iodine molecules was supported by crystallographic data. This work not only sets up a bridge between molecular rings and infinite porous networks but also reveals molecular details for the underlying host–guest binding interactions at crystallographic resolution.
Heterometallic frameworks constructed from aluminum molecular rings of varying size, flexible copper ions, and conjugated carboxylate ligands act as adsorbents for the sequential confinement of iodine molecules. This work not only sets up a bridge between molecular rings and infinite porous networks but also reveals molecular details for the underlying host–guest binding interactions at crystallographic resolution.
Monitoring the ammonia gas is of great interest to both environmental benefits and human health. The recent advance in polymer thin film transistors (TFTs) can realize high sensitivity and low‐cost ...gas sensors. Ammonia gas interacts with charge carrier channels and polymer/dielectrics interface through Coulomb force. This is the first report of high sensitivity and reusable ammonia sensor fabricated from thiophene‐isoindigo donor–acceptor conducting polymer. This kind of polymer has advantages of simple synthesis and excellent air stability. The systematic study is carried out to investigate relationship among chemical structure variation and morphology control of polymer to the performance of ammonia sensor. High crystallinity, favored crystal orientation, and direct percolation routes for analytes are found to be essential to increase the susceptibility of polymers to ammonia gas. By strengthening edge‐on morphology, the sensitivity can be enhanced fivefold for the same polymer. The idea can put forward the development of sensor array in a time‐efficient manner by employing the morphology effect.
The first high sensitivity ammonia sensor based on isoindigo donor–acceptor conducting polymer is successfully developed. The air stable polymers can be synthesized easily and fabricated into sensor by simple spin‐coating. Controlling crystallinity and morphology are crucial to achieve high sensitivity. A detection limit of 1 ppm is achieved by strengthening the edge‐on morphology of thin film in transistor.
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