Latest ArticlesSingle-cell imaging, a powerful analytical method to study single-cell behavior, such as gene expression and protein profiling, provides an essential basis for modern medical diagnosis. The coding and localization function of microfluidic chips has been developed and applied in living single-cell imaging in recent years. Simultaneously, chip-based living single-cell imaging is also limited by complicated trapping steps, low cell utilization, and difficult high-resolution imaging. To solve these problems, an ultra-thin temperature-controllable microwell array chip (UTCMA chip) was designed to develop a living single-cell workstation in this study for continuous on-chip culture and real-time high-resolution imaging of living single cells. The chip-based on ultra-thin ITO glass is highly matched with an inverted microscope (or confocal microscope) with a high magnification objective (100 × oil lens), and the temperature of the chip can be controlled by combining it with a home-made temperature control device. High-throughput single-cell patterning is realized in one step when the microwell array on the chip uses hydrophilic glass as the substrate and hydrophobic SU-8 photoresist as the wall. The cell utilization rate, single-cell capture rate, and microwell occupancy rate are all close to 100% in the microwell array. This method will be useful in rare single-cell research, extending its application in the biological and medical-related fields, such as early diagnosis of disease, personalized therapy, and research-based on single-cell analysis.
With the ever-growing demand of clean water for the healthy world, water purification has become an urgent global issue. Singlet oxygen (1O2) as unique non-radical derivative of oxygen, possessing unoccupied π* orbital and exhibiting high selectivity towards electron-rich organic pollutants. Nevertheless, most of the approaches suffer from low-efficiency or biotoxicity, which severely restrict their potential applications. Therefore, in this work, we propose a general strategy via photoelectrocatalytic for selectively reducing oxygen to 1O2 with designed carbon bridged carbon nitride (CBCN). This work highlights the important role of synergistic photo-electro-catalytic effect for selectively generating the 1O2 via oxygen reduction pathway, which can be a promising way especially for degrading electron-rich pollutants.
A facile hydrothermal method was applied to gain stably and highly efficient CuO-CeO2 (denoted as Cu1Ce2) catalyst for toluene oxidation. The changes of surface and inter properties on Cu1Ce2 were investigated comparing with pure CeO2 and pure CuO. The formation of Cu-Ce interface promotes the electron transfer between Cu and Ce through Cu2+ + Ce3+ ↔ Cu+ + Ce4+ and leads to high redox properties and mobility of oxygen species. Thus, the Cu1Ce2 catalyst makes up the shortcoming of CeO2 and CuO and achieved high catalytic performance with T50 = 234 ℃ and T99 = 250 ℃ (the temperature at which 50% and 90% C7H8 conversion is obtained, respectively) for toluene oxidation. Different reaction steps and intermediates for toluene oxidation over Cu1Ce2, CeO2 and CuO were detected by in situ DRIFTS, the fast benzyl species conversion and preferential transformation of benzoates into carbonates through C=C breaking over Cu1Ce2 should accelerate the reaction.
A facile approach was successfully employed to prepare Fe2O3/Co3O4 nanosheet arrays on nickel foams (Fe2O3/Co3O4@NF), which owned such advantages as narrow band gap energies and high separation rate of photoexcited electron-hole pairs. The combination of Fe2O3 and Co3O4 dramatically enhanced the photocatalytic activity towards sulfamethoxazole (SMZ) degradation, with the highest catalytic efficiency of k = 0.0538 min−1, which was much higher than that of Fe2O3@NF (0.0098 min−1) and Co3O4@NF (0.0094 min−1). The introduction of Ni foam could not only act as the support to anchor photocatalyst, but also work as the electron mediator to promote the transition of electron-hole pairs. Reactive species trapping experiments combined with electron paramagnetic resonance analysis confirmed ·O2− was primarily responsible for SMZ degradation. Furthermore, Fe2O3/Co3O4@NF was effective and almost unaffected by inorganic cations and anions in aqueous solution. This study could provide a facile and promising path for the construction of self-supported metal oxide-based heterojunction with high efficiency and strong stability.
The rapid development of next-generation flexible electronics stimulates the growing demand for flexible and wearable power sources with high energy density. Li metal capacitor (LMC), combining with a Li metal anode and an activated carbon cathode, exhibits extremely high energy density and high power density due to the unique energy storage mechanism, thus showing great potential for powering wearable electronic devices. Herein, a flexible LMC based on an in situ prepared PETEA-based gel polymer electrolyte (GPE) was reported for the first time. Owing to the high ionic conductivity of PETEA-based GPE (5.75 × 10-3 S/cm at 20 ℃), the assembled flexible LMC delivers a high capacitance of 210 F/g at 0.1 A/g within the voltage range from 1.5 V to 4.3 V vs. Li/Li+, a high energy density of 474 Wh/kg at 0.1 A/g and a high power density of 29 kW/kg at 10 A/g. More importantly, PETEA-based GPE endows the LMC with excellent flexibility and safety, which could work normally under abuse tests, such as bending, nail penetration and cutting. The in situ prepared PETEA-based GPE simplifies the fabrication process, avoids the risk of leakage and inhibits the growth of Li dendrite, making LMC a promising flexible energy storage device for the flexible electronic field.
Recently, widespread attention has been devoted to the typical layered BiOCl or BiOBr because of the suitable nanostructure and band structure. However, owing to the fast carrier recombination, the photocatalytic performance of BiOX materials is not so satisfactory. Loading 1T phase WS2 nanosheets (NSs) onto Bi5O7Br NSs can improve the photocatalytic N2 fixation activity. Among these, the obtained 1T-WS2@Bi5O7Br composites with optimum 5% 1T-WS2 NSs display a significantly improved photocatalytic N2 fixation rate (8.43 mmol L-1h-1g-1), 2.51 times higher than pure Bi5O7Br (3.36 mmol L-1h-1g-1). And the outstanding stability of 1T-WS2@Bi5O7Br-5 composites is also achieved. Exactly, the photoexcited electrons from Bi5O7Br NSs are quickly transferred to conductive 1T phase WS2 as electron acceptors, which can promote the separation of carriers. In addition, 1T-WS2 NSs can provide abundant active sites on the basal and edge planes, which can promote the efficiency of photocatalytic N2 fixation. This work offers a novel solution to improve the photocatalytic performance of Bi5O7Br NSs.
Modifying electrochemical surface area (ECSA) and surface chemistry are promising approaches to enhance the capacities of oxygen cathodes for lithium-oxygen (Li-O2) batteries. Although various chemical approaches have been successfully used to tune the cathode surface, versatile physical techniques including plasma etching etc. could be more effortless and effective than arduous chemical treatments. Herein, for the first time, we propose a facile oxygen plasma treatment to simultaneously etch and modify the surface of Co3O4 nanosheet arrays (NAs) cathode for Li-O2 batteries. The oxygen plasma not only etches Co3O4 nanosheets to enhance the ECSA but also lowers the oxygen vacancy concentration to enable a Co3+-rich surface. In addition, the NA architecture enables the full exposure of oxygen vacancies and surface Co3+ that function as the catalytically active sites. Thus, the synergistic effects of enhanced ECSA, modest oxygen vacancy and high surface Co3+ achieve a significantly enhanced reversible capacity of 3.45 mAh/cm2 for Co3O4 NAs. This work not only develops a promising high-capacity cathode for Li-O2 batteries, but also provides a facile physical method to simultaneously tune the nanostructure and surface chemistry of energy storage materials.
Triphenylamine (TPA) derivatives and their radical cation counterparts have successfully demonstrated a great potential for applications in a wide range of fields including organic redox catalysis, organic semiconductors, magnetic materials, etc., mainly because of their excellent redox activity. The stability of TPA radical cation has significant effect on the properties of the TPA-based functional materials, especially in relation to their electronic properties. Considering the instability of parent TPA radical cation, many efforts have been devoted to the development of stable TPA radical cations and related materials. Among them, TPA radical cation-based macrocycles have attracted particular attention because their large delocalized structures can stabilize the TPA radicals, thus endow them with outstanding redox behaviors, multiple resonance structures, and wide application in various optoelectronic devices. In this review, we give a brief introduction of organic radicals and the documented stable TPA radicals. Subsequently, a number of TPA radical cation-based macrocycles are comprehensively surveyed. It is expected that this minireview will not only summarize the recent development of TPA radical cations and their macrocycles, but also shed new light on the prospect of the design of more sophisticated radical cation-based architectures and related materials.
This work presents a novel strategy for engineering a GC stationary phase with high selectivity, inertness and thermal stability by introducing the 3D π-rich TP moieties to the terminals of a polar chain polymer. Herein, we provide the first example, i.e., a new TP-terminated polycaprolactone polymer (TPP) as the stationary phase for GC analyses. As demonstrated, the TPP column achieved distinctly improved inertness to fatty acids and aldehydes, and dramatically enhanced thermal stability (about 100 ℃ higher) over the PCL column. Also, the TPP column exhibited high resolving capability towards the positional isomers of phenols, anilines and alkylated/halobenzenes and showed good potential in detecting minor impurities in chemical products. Importantly, the proposed strategy is facile, feasible and generally applicable to analogous polymers.
Bandgap engineering through single-atom site binding on semiconducting photocatalyst can boost the intrinsic activity, selectivity, carrier separation, and electron transport. Here, we report a mixed-valence Ag(0) and Ag(Ⅰ) single atoms co-decorated semiconducting chalcopyrite quantum dots (Ag/CuFeS2 QDs) photocatalyst. It demonstrates efficient photocatalytic performances for specific organic dye (rhodamine B, denoted as RhB) as well as inorganic dye (Cr(Ⅵ)) removal in water under natural sunlight irradiation. The RhB degradation and Cr(Ⅵ) removal efficiencies by Ag/CuFeS2 QDs were 3.55 and 6.75 times higher than those of the naked CuFeS2 QDs at their optimal pH conditions, respectively. Besides, in a mixture of RhB and Cr(Ⅵ) solution under neutral condition, the removal ratio has been elevated from 30.2% to 79.4% for Cr(Ⅵ), and from 95.2% to 97.3% for RhB degradation by using Ag/CuFeS2 QDs after 2 h sunlight illumination. The intrinsic mechanism for the photocatalytic performance improvement is attributed to the narrow bandgap of the single-atomic Ag(Ⅰ) anchored CuFeS2 QDs, which engineers the electronic structure as well as expands the optical light response range. Significantly, the highly active Ag(0)/CuFeS2 and Ag(Ⅰ)/CuFeS2 effectively improve the separation efficiency of the carriers, thus enhancing the photocatalytic performances. This work presents a highly efficient single atom/QDs photocatalyst, constructed through bandgap engineering via mixed-valence single noble metal atoms binding on semiconducting QDs. It paves the way for developing high-efficiency single-atom photocatalysts for complex pollutions removal in dyeing wastewater environment.