Organic–inorganic hybrid perovskite (OIHPs) solar cells are the most promising alternatives to traditional silicon solar cells, with a certified power conversion efficiency beyond 25%. However, the ...poor stability of OHIPs is one of the thorniest obstacles that hinder its commercial development. Among all the factors affecting stability, ion migration is prominent because it is unavoidable and intrinsic in OHIPs. Therefore, it is important to understand the mechanism for ion migration and regulation strategies. Herein, the types of ions that may migrate in OHIPs are first discussed; afterward, the migrating channels are demonstrated. The effects of ion migration are further elaborated. While ion migration can facilitate the p–i–n structure in some cases, the current hysteresis and other adverse effects such as phase segregation in OHIPs attract widespread attention. Based on these, several recent strategies to suppress the ion migration are enumerated, including the introduction of alkali cations, organic additives, grain boundaries passivation, and employment of low‐dimensional perovskites. Finally, the prospect for further modulating the ion migration and more stable perovskite solar cells is proposed.
The origin of ion migration in organic–inorganic hybrid perovskites (OIHPs) is first reviewed. The ions that may migrate in OHIPs and migrating channels are further discussed in detail. The effects of ion migration on OHIPs are explored and some recently emerged regulation strategies are summarized. A perspective on further inhibition of ion migration in OHIPs is also provided.
Exploring stable and efficient lead‐free perovskite solar cells (PSCs) is critical to solving the environmental concerns caused by lead. Recently, tin halide perovskites (THPs) have become a ...promising candidate due to its low toxicity and similar electronic configuration to lead counterparts. Currently, the power conversion efficiency of tin‐based PSCs (TPSCs) has been pushed over 14%. However, there is still a considerable gap compared to lead PSCs due to the non‐negligible open‐circuit voltage loss (Vloss). Therefore, understanding the origins and regulation strategies of Vloss for TPSCs is of great importance. Herein, the nature of THPs is first reviewed from the crystal structure, electronic structure, and phase transition. Subsequently, the origins and determinants of Vloss are discussed in TPSCs. Besides the intrinsic low bandgap, the bulk recombination of tin perovskite, and the non‐radiative recombination of the associated interfaces induce the Vloss of the TPSCs devices. Then, some recently emerged strategies to suppress the Vloss in TPSCs are introduced. Finally, a perspective on the further suppression of Vloss in TPSCs including purifying the precursor solution, suppressing the oxidation Sn2+, and optimizing the device structure is outlined.
This review starts with the basic physical properties of tin halide perovskites and subsequently presents the origin of open‐circuit voltage loss (Vloss) in tin halide perovskite solar cells (TPSCs) in detail. Some recently emerged strategies to suppress Vloss in TPSCs are further summarized, together with a perspective on the development of TPSCs.
Ni single atoms are anchored on ultrathin g-C3N4 to obtain high selective H2O2 production through a one-step 2e− O2RR process.
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•Morphology modification and single atoms contribute ...superior photocatalytic H2O2 production.•H2O2 production is through a one-step two-electron reduction pathway with selectivity of 87.3 %.•A high H2O2 generation rate of 27.11 mmol g−1h−1 and AQY of 8.56% are obtained in neutral condition.•NiCN-4 catalyst shows photocatalytic activities of both H2O2 production and TC degradation.
Photocatalysis technology provides a promising and effective method for hydrogen peroxide (H2O2) production. Nevertheless, the photocatalytic H2O2 production activity is greatly regulated by the two-electron oxygen reduction reaction (2e− O2RR). Herein, we demonstrate a robust single atom photocatalyst (NiCN-x, Ni single atoms anchored on ultrathin g-C3N4) for artificial H2O2 production under visible light irradiation. A high H2O2 generation rate of 27.11 mmol g−1h−1 and an apparent quantum yield (AQY) of 8.56 % at 400 nm are both obtained in the optimal NiCN-4 photocatalytic system. Furthermore, NiCN-4 catalyst shows relatively high selectivity of H2O2 with 87.3 % through using a rotating ring-disk electrode (RRDE) measurement. Furthermore, NiCN-4 shows enhanced photocatalytic TC decomposition with degradation efficiency of 89.4 %. Based on DFT calculation, experimental results and advanced characterizations, we find that the high photocatalytic performance is attributed to the boosting 2e−O2RR process with the formation of Ni-μ-peroxide (Ni-OOH) and the unique electronic feature of Ni-Nx coordination sites. This study offers a new blueprint for the fabrication of single atom catalysts (SACs) to achieve artificial photosynthesis of H2O2 with high selectivity and degradation of organic pollutants.
Cancer is one of the most devastating diseases, and recently, a variety of natural compounds with preventive effects on cancer developments have been reported. Sulforaphane (SFN) is a potent ...anti-cancer isothiocyanate originating from Brassica oleracea (broccoli). SFN, mainly metabolized via mercapturic acid pathway, has high bioavailability and absorption. The present reviews mainly discussed the metabolism and absorption of SFN and newly discovered mechanistic understanding recent years for SFN's anti-cancer effects including promoting autophagy, inducing epigenetic modifications, suppressing glycolysis and fat metabolism. Moreover, its inhibitory effects on cancer stem cells and synergetic effects with other anti-cancer agents are also reviewed along with the clinical trials in this realm.
Big data analysis has found applications in many industries due to its ability to turn huge amounts of data into insights for informed business and operational decisions. Advanced data mining ...techniques have been applied in many sectors of supply chains in the food industry. However, the previous work has mainly focused on the analysis of instrument‐generated data such as those from hyperspectral imaging, spectroscopy, and biometric receptors. The importance of digital text data in the food and nutrition has only recently gained attention due to advancements in big data analytics. The purpose of this review is to provide an overview of the data sources, computational methods, and applications of text data in the food industry. Text mining techniques such as word‐level analysis (e.g., frequency analysis), word association analysis (e.g., network analysis), and advanced techniques (e.g., text classification, text clustering, topic modeling, information retrieval, and sentiment analysis) will be discussed. Applications of text data analysis will be illustrated with respect to food safety and food fraud surveillance, dietary pattern characterization, consumer‐opinion mining, new‐product development, food knowledge discovery, food supply‐chain management, and online food services. The goal is to provide insights for intelligent decision‐making to improve food production, food safety, and human nutrition.
•US-CD significantly improved antioxidant capacity and total phenolic content of dried apples.•US-CD reduced drying time by nearly 45% compared to traditional hot air drying (HAD).•US-CD reserved the ...micro-structure of the dried apples better than the HAD samples.•US-CD samples had improved rehydration ratio, color, and textural properties compared to the HAD treatment.
Drying is one of the most prevalent methods to reduce water activity and preserve foods. However, it is also the most energy-intensive food processing unit operation. Although a number of drying methods have been proposed and tested for the purpose of achieving a time- and energy-efficient drying process, almost all current drying methods still rely on thermal energy to remove moisture from the product. In this study, a novel use of power ultrasound was explored for drying of apple slices without the application of heat. The non-thermal ultrasound contact drying (US-CD) was performed in the presence of an air stream (26–40 °C) flowing over product surface to remove mist or vapor produced by the ultrasound treatment. The effects of the non-thermal US-CD, hot-air drying (HAD), and freeze drying (FD) on the changes in rehydration ratio, pH, titratable acidity, water activity, color, glass transition temperature, texture, antioxidant capacity, total phenols, and microstructures of the samples were evaluated. The moisture content of the apple slices reached below 5% (w.b.) after 75–80 min of US-CD, which was about 45% less than that of the HAD method. The antioxidant capacity and total phenol contents of the US-CD samples were significantly higher than that of the AD samples. The non-thermal ultrasonic contact drying is a promising method which has the potential to significantly reduce drying time and improve product quality.
Metal oxide semiconductor heterojunctions (MOSHs) can enhance the performance of ethanol gas sensors substantially. Ethanol gas sensors based on MOSHs are cost-effective and have excellent sensing ...response, good selectivity, fast response and recovery, long-term stability or repeatability, a low operating temperature, a facile fabrication process, and versatile applications. This paper reviews the recent advances in gas sensors that are based on MOSHs and the advantages of using them to detect ethanol gas. According to the literature, compared with ethanol gas sensors that use single-component sensing materials, the MOSHs exhibit superior performance due to the synergy between the different components, which can amplify the reception and transduction components of the sensor signals. To the best of our knowledge, heterojunctions can be grouped into four main categories as metal oxide/metal oxide, metal oxide/metal sulfide, metal oxide/noble metal, and metal oxide/other materials, including rare-earth metals, g-C
3
N
4
, and graphene, heterojunctions. The future trends and challenges that would be faced in the development of ethanol gas sensors based on MOSHs are discussed in detail. Finally, critical ideas and thinking regarding the future progress of MOSH-based gas sensors are presented.
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•The formation of Schottky barrier in MONC-3 can inhibit the backflow of electrons.•MONC-3 can convert the absorbed light energy into local high temperature.•Photodynamic and ...photothermal effects synergistically lead to bacterial death.•DFT calculation clarifies the charge transfer mechanism in Schottky heterojunction.
Developing green and highly efficient water disinfection technique is of great importance to public health. Herein, a near-infrared (NIR) light-triggerable thermo-sensitive defective molybdenum oxide-nitrogen doped carbon (MoO3-x/NCNs) composite was fabricated and applied to water disinfection. With the synergy of photodynamic and photothermal effects, the MoO3-x/NCNs achieve a rapid and effective inactivation of Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) as compared to photocatalytic treatment or thermal catalytic alone. Particularly, MONC-3 with optimal ratio can completely inactivate 7.6 log of E. coli and S. aureus within 60 min and 100 min, respectively. The MONC-3 hybrid exhibits efficient charge separation and migration ability due to the formation of Schottky heterojunction, resulting in the highly enhanced O2− (11.34 × 10−10 M) generation activity. Meanwhile, excellent NIR light absorption and photothermal conversion efficiency (52.6%) of MONC-3 can generate local high temperature to promote photocatalytic reaction rate and destruct the bacterial integrity. The monitoring of cell damage process confirmed the irreversible death of bacteria. Based on density functional theory (DFT) calculation, the antibacterial mechanism and Schottky effect were clarified. This work provides new insights for constructing a water disinfection strategy based on plasma-induced photothermal synergy catalysis.
Objectives:
COVID-19 is the most challenging public health crisis in decades in the United States. It is imperative to enforce social distancing rules before any safe and effective vaccines are ...widely available. Policies without public support are destined to fail. This study aims to reveal factors that determine the American public support for six mitigation measures (e.g., cancel gatherings, close schools, restrict non-essential travel).
Methods:
Based on a nationally representative survey, this study uses Structural Equation Modelling to reveal the relationships between various factors and public support for COVID-19 mitigation.
Results:
1). Democrats are more likely than Republicans to support mitigation measures; 2).Favorability towards the political leader (Biden or Trump) can slant public support for COVID-19 mitigation measures among different segments of the public.; 3). Indirect experience, rather than direct experience with COVID-19 can motivate people to support mitigation; 4). Concern for COVID-19 is a strong motivator of support for mitigation.
Conclusion:
Political polarization poses an enormous challenge to societal well-being during a pandemic. Indirect experience renders COVID-19 an imminent threat.
Increasing attention has been paid to the safety and efficiency of batteries due to the rapid development and widespread use of electric vehicles. Solid-state batteries have the advantages of good ...safety, high energy density, and strong cycle performance, and are recognized as the next generation of power batteries. However, solid-state batteries generate large stress changes due to the volume change of electrode materials during cycling, resulting in pulverization and exfoliation of active materials, fracture of solid-electrolyte interface films, and development of internal cracks in solid electrolytes. As a consequence, the cycle performance of the battery is degraded, or even a short circuit can occur. Therefore, it is important to study the stress changes of solid-state batteries or electrode materials during cycling. This review presents a current overview of chemo-mechanical characterization techniques applied to solid-state batteries and experimental setups. Moreover, some methods to improve the mechanical properties by changing the composition or structure of the electrode materials are also summarized. This review aims to highlight the impact of the stress generated inside solid-state batteries and summarizes a part of the research methods used to study the stress of solid-state batteries, which help improve the design level of solid-state batteries, thereby improving battery performance and safety.
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