For realizing scalable solar hydrogen synthesis, the development of visible-light-absorbing photocatalysts capable of overall water splitting is essential. Metal sulfides can capture visible light ...efficiently; however, their utilization in water splitting has long been plagued by the poor resilience against hole oxidation. Herein, we report that the ZnIn2S4 monolayers with dual defects (Ag dopants and nanoholes) accessed via cation exchange display stoichiometric H2 and O2 evolution in pure water under visible light irradiation. In-depth characterization and modeling disclose that the dual-defect structure endows the ZnIn2S4 monolayers with optimized light absorption and carrier dynamics. More significantly, the dual defects cooperatively function as active sites for water oxidation (Ag dopants) and reduction (nanoholes), thus leading to steady performance in photocatalytic overall water splitting without the assistance of cocatalysts. This work demonstrates a feasible way for fulfilling “all-in-one” photocatalyst design and manifests its great potential in addressing the stability issues associated with sulfide-based photocatalysts.
Hierarchical NiCo2O4@NiCo2O4 core/shell nanoflake arrays on nickel foam for high-performance supercapacitors are fabricated by a two-step solution-based method which involves in hydrothermal process ...and chemical bath deposition. Compared with the bare NiCo2O4 nanoflake arrays, the core/shell electrode displays better pseudocapacitive behaviors in 2 M KOH, which exhibits high areal specific capacitances of 1.55 F cm–2 at 2 mA cm–2 and 1.16 F cm–2 at 40 mA cm–2 before activation as well as excellent cycling stability. The specific capacitance can achieve a maximum of 2.20 F cm–2 at a current density of 5 mA cm–2, which can still retain 2.17 F cm–2 (98.6% retention) after 4000 cycles. The enhanced pseudocapacitive performances are mainly attributed to its unique core/shell structure, which provides fast ion and electron transfer, a large number of active sites, and good strain accommodation.
UiO-66-(OH)2 emits yellow-green light under ultraviolet light. With adding Fe3+, fluorescence quenching occurs because of the nonradiative electron/hole recombination annihilation. Ascorbic acid (AA) ...can reduce Fe3+ to Fe2+, which destroys the electron transfer between UiO-66-(OH)2 and Fe3+, leading to the fluorescence recovery of UiO-66-(OH)2.
Display omitted
In this research, a hydroxyl group functionalized metal-organic framework (MOF), UiO-66-(OH)2, was synthesized as a “on-off-on” fluorescent switching nanoprobe for highly sensitive and selective detection of Fe3+, ascorbic acid (AA) and acid phosphatase (ACP). UiO-66-(OH)2 emits yellow-green light under ultraviolet light, when Fe3+ was added, Fe3+ was chelated with hydroxyl group, the electrons in the excited state S1 of the MOF transferred to the half-filled 3d orbits of Fe3+, resulting in fluorescence quenching because of the nonradiative electron/hole recombination annihilation. AA could reduce Fe3+ to Fe2+, which can destroy the electron transfer between UiO-66-(OH)2 and Fe3+ after AA adding, resulted in nonoccurrence of the nonradiative electron transfer, leading to the recovery of UiO-66-(OH)2 fluorescence intensity. The probe can also be used to detect ACP based on the enzymolysis of 2-phospho-l-ascorbic acid (AAP) to produce AA. Benefitting from the hydroxyl group and the characteristics of UiO-66, including the high porosity and large surface area, the developed UiO-66-(OH)2 showed extensive advantages as a fluorescent probe for detection of multi-component, such as high sensitivity and selectivity, colorimetric detection, fast response kinetics and easy to operate, economical and secure. This is the first time to use active group functionalized MOFs as a multi-component sensor for these three substances detection.
The development of high‐performance dendrite‐free liquid‐metal anodes at room temperature is of great importance for the advancement of alkali metal batteries. Herein an intriguing self‐healing ...liquid dendrite‐free Na–K alloy, fabricated by a facile room‐temperature alloying process, aiming for application in potassium‐ion batteries is reported. Through extensive investigation, its self‐healing characteristics are rooted upon a thin solid K2O layer (KOL) coated on the liquid Na–K alloy. The KOL not only acts as a protective layer to prevent the Na–K alloy from making contact with the electrolyte, but also greatly improves the wetting capability and adhesion between the liquid alloy and the carbon matrix (e.g., carbon fiber cloth (CFC)) to form a stable interface. Consequently, the as‐prepared CFC/KOL@Na–K alloy anode exhibits prominent electrochemical performance with smaller hysteresis (less than 0.3 V beyond 140 cycles at 0.4 mA cm−2), better capacity retention, and higher Coulombic efficiency than the CFC/bare Na–K alloy counterpart. When coupled with a potassium Prussian blue (PPB) cathode, the full cell manifests higher capability retention and improved cycling stability. This research deepens the understanding of self‐healing Na–K alloys and opens a new way to achieve high‐performance dendrite‐free alkali metal anodes for application in rechargeable batteries.
A dendrite‐free self‐healing K2O@Na–K liquid alloy consisting of a Na–K liquid core and a solid K2O shell is prepared by a facile room‐temperature alloying process. Due to the excellent seal‐healing ability, enhanced wetting properties, and strong adhesion with a carbon fiber cloth (CFC) matrix, the designed CFC/KOL@Na–K alloy electrode exhibits noticeable electrochemical performance with smaller hysteresis, better cycling stability, and higher Coulombic efficiency.
The uncertainty and intermittency of renewable energy sources pose a challenge to generation scheduling of microgrids. This paper presents a hierarchical framework to handle the uncertainty and ...realize an economic generation schedule of microgrids. The lower level combines a battery energy-storage system (BESS) with renewable energy sources, targeting maximal utilization of renewable power and minimal deviation from the schedule, to provide an optimal generation plan in the day-ahead market. The upper level minimizes the total cost of the microgrid by the genetic algorithm (GA) to yield an economic generation plan of dispatchable distributed generators (DGs) based on the lower level. Two stages of such hierarchical scheduling before and in the day gradually reduce the uncertainty, and lead the overall schedule to evolve toward a stable and economic one. The method is tested on a 14-bus microgrid system. The simulation indicates that the wind turbine and photovoltaic are gradually stabilized by BESS Besides, the operation is scheduled economically, and cheap DGs are always arranged in priority.
China's current immunization program was revised in 2007. Some common childhood vaccines such as those for influenza, pediatric pneumonia, Haemophilus influenzae, varicella, and rotavirus have not ...been included in the National Immunization Program (NIP) and need to be purchased by children's guardians at their own expense. Rural areas, constrained by economic development and vaccine awareness, have a low non-NIP vaccination rate and more family medical expenses and social burden. This study aims to examine the awareness and attitude of rural parents about non-NIP vaccines and relevant factors influencing their vaccination intention to provide strategic suggestions for expanding and improving the Chinese government's NIP policy.
A qualitative method of in-depth interviews were conducted for this study. We interviewed 30 rural parents in a central Chinese village to investigate their awareness of non-NIP vaccines and their vaccination intention and behavior. All the interview data were analyzed through the Colaizzi seven-step data analysis method.
This study summarized the individual and social level factors influencing the non-NIP vaccination intention of rural parents. The individual level factors include four themes: perceived severity with physical harm, treatment consumption (cost of the treatment of the subject diseases), psychological burden, and social consequences being subthemes; perceived vulnerability with age vulnerability, medical history, immune quality (children's underlying immune status), and environmental vulnerability (sanitary condition of the rural environment) as subthemes; perceived efficacy with effect perception, psychological comfort, protective strength, and functional compensation (functions of non-NIP vaccines unreplaceable by NIP vaccines) being subthemes; and perceived cost consisting of two subthemes cost burden and adverse reaction. The social level influencing factors include the vaccination opinions in rural social networks, the accessibility of health services and vaccine products, and the guidance and promotion of vaccination policies. These factors act outside of individuals' subjective awareness and influence decisions regarding non-NIP vaccination in rural areas.
Based on these influencing factors, this study constructs a structural model for non-NIP vaccination decision-making process in rural areas of China. The results play a guiding role in directing attention to children's health, promoting non-NIP vaccination, facilitating the dissemination of vaccine knowledge in rural areas, and improving NIP policies and practices in China.
Scrupulous design and fabrication of advanced electrode materials are vital for developing high-performance sodium ion batteries. Herein, we report a facile one-step hydrothermal strategy for ...construction of a C-MoSe2/rGO composite with both high porosity and large surface area. Double modification of MoSe2 nanosheets is realized in this composite by introducing a reduced graphene oxide （rGO） skeleton and outer carbon protective layer. The MoSe2 nanosheets are well wrapped by a carbon layer and also strongly anchored on the interconnected rGO network. As an anode in sodium ion batteries, the designed C-MoSe2/rGO composite delivers noticeably enhanced sodium ion storage, with a high specific capacity of 445 mAh-g-1 at 200 mA.g-1 after 350 cycles, and 228 mAh-g 1 even at 4 A.g-1; these values are much better than those of C-MoSe2 nanosheets （258 mAh.g-a at 200 mA-g-1 and 75 mAh-g-1 at 4 A.g-~）. Additionally, the sodium ion storage mechanism is investigated well using ex situ X-ray diffraction and transmission electron microscopy methods. Our proposed electrode design protocol and sodium storage mechanism may pave the way for the fabrication of other high-performance metal diselenide anodes for electrochemical energy storage.
Chimeric antigen receptor (CAR)-T cell therapy has shown remarkable clinical efficacy against B-cell malignancies, yet marked vulnerability to antigen escape and tumor relapse exists. Here we report ...the rational design and optimization of bispecific CAR-T cells with robust activity against heterogeneous multiple myeloma (MM) that is resistant to conventional CAR-T cell therapy targeting B-cell maturation antigen (BCMA). We demonstrate that BCMA/CS1 bispecific CAR-T cells exhibit superior CAR expression and function compared to T cells that co-express individual BCMA and CS1 CARs. Combination therapy with anti-PD-1 antibody further accelerates the rate of initial tumor clearance in vivo, while CAR-T cell treatment alone achieves durable tumor-free survival even upon tumor re-challenge. Taken together, the BCMA/CS1 bispecific CAR presents a promising treatment approach to prevent antigen escape in CAR-T cell therapy against MM, and the vertically integrated optimization process can be used to develop robust cell-based therapy against novel disease targets.
A dual cocatalyst system consisting of Pt and PdS combined with CdS shows exceptionally high quantum efficiency for photocatalytic H2 production. Pt and PdS act as reduction and oxidation cocatalyst, ...respectively. Junctions are formed between the cocatalysts and semiconductor. The co-loading of Pt and PdS can suppress recombination of photogenerated electron-hole pairs, is thus held responsible for the high quantum efficiency. Display omitted
► The essentials of the exceptionally high quantum efficiency (93%) were investigated. ► The mechanism of photocatalytic course was studied by in situ measurement. ► PdS and Pt act as the oxidation and reduction co-catalysts, respectively. ► The recombination of photo-generated charges is suppressed by co-catalysts. ► Atomic junctions between the co-catalysts and CdS are formed.
The essentials of the exceptionally high quantum efficiency (93%) of photocatalytic hydrogen production on Pt–PdS/CdS have been investigated by studying the roles of the dual cocatalysts Pt and PdS in photocatalysis. In situ photoelectrochemical measurements, photoluminescence spectroscopy and high-resolution transmission electron microscopy characterizations indicate that the exceptionally high QE can be attributed to vital factors including PdS and Pt as the oxidation and reduction cocatalysts, respectively; the efficient utilization of the photogenerated electrons, including those at the shallow trap states of CdS, for photocatalytic reactions; and the facial charge transfer between the cocatalysts and CdS through atomic heterojunctions. Combinations of Pt with other metal sulfides and PdS with other noble metals as dual cocatalysts also show an evident synergetic effect on the activity. The co-loading of Pt and PdS on other sulfide semiconductors results in the same enhancement of photocatalytic activity. It is proposed that the crucial role of dual cocatalysts is general for photocatalysis.
Lithium (Li) metal is considered as one of the most promising anode materials for next‐generation high‐energy‐density storage systems. However, the practical application of Li metal anode is hindered ...by interfacial instability and air instability due to the highly reactivity of Li metal. Unstable interface in Li metal batteries (LMBs) directly dictates Li dendrite growth, “dead Li” and low Coulombic efficiency, resulting in inferior electrochemical performance of LMBs and even safety issues. In addition, its sensitivity to ambient air leads to the severe corrosion of Li metal anode, high requirements of production and storage, and increased manufacturing cost. Plenty of efforts in recent years have overcome many bottlenecks in these fields and hastened the practical applications of high‐energy‐density LMBs. In this review, we focus on emerging methods of these two aspects to fulfill a stable and low cost electrode. In this perspective, design artificial solid electrolyte interphase (SEI) layers, construct three‐dimensional conductive current collectors, optimize electrolytes, employ solid‐state electrolytes, and modify separators are summarized to be propitious to ameliorate interfacial stability. Meanwhile, ex situ/in situ formed protective layers are highlighted in favor of heightening air stability. Finally, several possible directions for the future research on advanced Li metal anode are addressed.
In this review, we summarize the feasible strategies of ameliorating interfacial stability and air stability of lithium metal anode to make it more suitable for practical applications in high‐energy‐density storage systems. Meanwhile, we propose the challenges and perspectives for the future research of lithium metal anode in high‐energy batteries.
PDF
