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The rapidly increasing demand for clean and efficient energy devices is a critical issue for the sustainable development of human society. The green and low-cost aqueous zinc–air batteries (ZABs) w...

As one of the most promising energy storage systems, conventional lithium-ion batteries based on the organic electrolyte have posed challenges to the safety, fabrication, and environmental friendliness. By virtue of the high safety and ionic conductivity of water, aqueous lithium-ion battery (ALIB) has emerged as a potential alternative. Whereas, the narrow electrochemical stability window (ESW) of water severely restricts the performance of ALIB. In recent years, with the introduction of water-in-salt electrolyte (21 mol LiTFSI in 1 kg H2O), the ESW of aqueous electrolyte was expanded to ~3 V, which significantly improved the voltage and energy density of ALIBs. Nevertheless, in view of such high salt concentration, water-in-salt electrolyte will dramatically increase the cost of ALIBs. Hence, due to their lower cost and abundant resource, aqueous sodium-ion batteries and zinc-based batteries show great potential. Herein, the latest advances of water-in-salt electrolyte in aqueous rechargeable batteries are briefly reviewed. Some challenges and prospects of water-in-salt electrolyte are also discussed to broaden the horizons for future development.

The rational design and controllable synthesis of excellent bifunctional oxygen reduction and evolution reaction (ORR/OER) electrocatalysts are of vital importance for zinc–air battery applications. Herein, we report nitrogen/sulfur-codoped carbon nanosheets (NSC) decorated with dense Co9S8/Co1−xS heterostructures (Co9S8/Co1−xS@NSC), prepared by a one-pot salt template-assisted pyrolysis procedure. The population of the Co9S8/Co1−xS heterostructure can be effectively controlled by tuning the precursor components. Salt templates constructed hierarchical porosity for the wide-open carbon nanosheets, which maximized the N functional groups to anchor highly dispersive Co9S8/Co1−xS species. Experiments and theoretical simulations revealed notable electronic interactions within Co9S8/Co1−xS interfaces, which can effectively optimize the adsorption/desorption behaviors of intermediates in ORR/OER, thus promoting the bifunctional electrocatalytic performance. The half-wave potential for the ORR of 0.86 V and the OER electrocatalytic potential of 1.52 V at 10 mA cm−2 were obtained. Benefiting from the strong coupling effect between the Co9S8/Co1−xS species and the carbon substrate, superior durability was obtained for 2000 ORR/OER cycles. The practical zinc–air battery based on the Co9S8/Co1−xS@NSC cathode manifested a high open-circuit voltage, small voltage gap and robust reversibility. Our study revealed the great potential of the bi-elemental (Co and S) heterostructure in enhancing the ORR/OER activity, which suggests a logical extension to other electrocatalysis systems.

Short-term electricity load forecasting has become increasingly important due to the privatization and deregulation in the energy market. This study proposes a probabilistic learning method to predict hour-ahead and day-ahead load demand. Unlike methods in previous studies, the proposed method integrates wavelet transform and feature selection as key preprocessing steps. Features are divided into current state related features and historical information related features. Current state related features are forecasted by the regression model before being added into the load prediction model. The entire learning and prediction process is based on the relevance vector machine (RVM) that utilizes load data characteristics. A number of test cases are presented using benchmark datasets from the New York Independent System Operator (NYISO) and ISO New England. Based on the detailed empirical comparison, the proposed RVM-based integrated method outperforms classical time series approaches and state-of-the-art artificial intelligence methods on short-term load forecasting.

In this paper, the tests under biaxial compression were conducted on five kinds of recycled aggregate concrete (RAC) by stress ratios (0:−1, −0.1:−1, −0.25:−1, −0.5:−1, −0.75:−1, and −1:−1) at the strain rates of 10–5/s, 10–4/s, 10–3/s, and 10–2/s. This study was accomplished in the servo-hydraulic multi-axial testing system, which was carried at Dalian University of Technology. The experimental phenomena of RAC under biaxial compression are described, and the experimental results of biaxial compressive strength of RAC are analyzed. The effects of strain rate, stress ratio, and substitution percentages of recycled coarse aggregate (RCA) on the biaxial compressive strength of RAC were studied. During the experiments, the failure modes of concrete have not been changed because of the increased impact of the RCA on RAC. The strength of RAC is improved with the increase in strain rates. With the increase in stress ratios, the biaxial compressive strength increases at first. However, the strength then decreases. Based on the strength theory of common concrete and analysis of experimental data, this paper built a new dynamic strength criterion. The biaxial compressive strength criterion describes the characteristics of structural RAC at different stress ratios and strain rates. This strength criterion can provide theoretical foundation for future concrete multi-axis dynamic tests and the design specification with the considerations of multi-axis dynamic strength and nonlinear analysis. The feature of the model is that it can take into account the influence of strain rates.

The rapid consumption of fossil fuels has caused increasingly climatic issues and energy crisis, which leads to the urgent demand for developing sustainable and clean energies. Electrocatalysts play a key role in the development of electrochemical energy conversion and storage devices. Especially, developing efficient and cost-effective catalysts is important for the large-scale application of these devices. Among various electrocatalyst candidates, earth abundant transition metal compound (TMC)-based electrocatalysts are being widely and rapidly studied owing to their high electrocatalytic performances. This paper reviews the recent and representative advances in efficient TMC-based electrocatalysts (i.e., oxides, sulfides, selenides, phosphides, carbides and nitrides) for energy electrocatalytic reactions, including hydrogen evolution reaction (HER), oxygen evolution reaction (OER) and oxygen reduction reaction (ORR). Different compounds with different applications are summarized and the relative mechanisms are also discussed. The strategies for developing earth-abundant and low-cost TMC-based electrocatalysts are introduced. In the end, the current challenges and future perspectives in the development of TMC research are briefly discussed. This review also provides the latest advance and outlines the frontiers in TMC-based electrocatalysts, which should provide inspirations for the further development of low-cost and high-efficiency catalysts for sustainable clean energy technologies.

Data-driven methods for machinery health monitoring and prediction, such as machine learning and statistical pattern recognition techniques, normally requires high quality (less noised), frequently-sampled and large volume time-series data to estimate proper models between system inputs and outputs. However, most of the industrial time-series are highly noisy and only few types of sensory data are available, which challenges the estimation accuracy. This paper proposes a data-driven spectral decomposition framework (denoted as Koopman-CBM) for the machinery health monitoring and prediction problem. Specifically, considering noisy industrial signals in the form of one dimensional time-series, we use the higher-order dynamic mode decomposition (DMD) embeds time-lagged snapshots to increase the spatial complexity of low-dimensional time series and use the total-least-square algorithm to compensate the effect of measurement noise, thereby, extracting accurate dynamical features. The obtained de-noised model characteristics (i.e., eigenvalues, eigenfunctions, Koopman operator) is effective in predicting the system health stages. In parallel, using the Koopman operator as the linear predictor associated with the nonlinear dynamics, we can then perform remaining useful life (RUL) predictions with high accuracy. The experimental validation of the proposed framework is carried out on a rolling bearing datasets for degradation health-stage inspection and RUL prediction. Results show that– compared with other mainstream methods– our approach is capable of identifying the critical degradation stages and achieving higher RUL prediction accuracies.

Thin-felt ZSM-11/stainless-steel(SS)-fiber composites are successfully prepared via a combined washcoating and steam-assisted crystallization (SAC) method. Pre-aging of synthesis sol at a lower temperature of 80 °C can facilitate the zeolite nucleation and subsequent SAC growth at 180 °C. Such synthesis approach realizes the flexible tuning of acidity via adjusting SiO2/Al2O3 molar ratio in a wide range, including but not limited from 105 to 425. The as-synthesized ZSM-11/SS-fiber composites are employed as catalysts for the methanol-to-propylene reaction, and the promising thin-felt catalyst with SiO2/Al2O3 molar ratio of 200 shows remarkable stability improvement in comparison with its powdered counterpart, due to enhanced zeolite utilization efficiency and heat/mass transfer by the microfibrous-structured design.

Aqueous battery systems feature high safety, but they usually suffer from low voltage and low energy density, restricting their applications in large-scale storage. Here, we propose an electrolyte-decoupling strategy to maximize the full potential of Zn–MnO2 batteries by simultaneously enabling the optimal redox chemistry of both the Zn and MnO2 electrodes. The decoupled Zn–MnO2 battery exhibits an open-circuit voltage of 2.83 V (in contrast to the typical voltage of 1.5 V in conventional Zn–MnO2 batteries), as well as cyclability with only 2% capacity fading after deep cycling for 200 h. Benefiting from the full utilization of MnO2, the Zn–MnO2 battery is also able to maintain approximately 100% of its capacity at various discharge current densities. We also demonstrate the feasibility of integrating the Zn–MnO2 battery with a wind and photovoltaic hybrid power generating system. This electrolyte-decoupling strategy is shown to be applicable for other high-performance zinc-based aqueous batteries such as Zn–Cu and Zn–Ag batteries. Low energy density and limited cyclability are preventing the commercialization of aqueous Zn–MnO2 batteries. Here, the authors combine the merits of operating Zn anodes in alkaline conditions and MnO2 cathodes in acidic conditions, via an electrolyte-decoupling strategy, to realize high-performance batteries.

Batteries are considered as an attractive candidate for grid-scale energy storage systems (ESSs) application due to their scalability and versatility of frequency integration, and peak/capacity adjustment. Since adding ESSs in power grid will increase the cost, the issue of economy, that whether the benefits from peak cutting and valley filling can compensate for the cost input of adding energy storage system or not, is particularly concerned. Here we show how the cost of battery deployment can potentially be minimized by carrying out an economic assessment for the cases of different batteries applied in ESSs. To make this analysis, we develop a techno-economic model and apply it to the cases of ESSs with batteries in applications. Our results show that batteries could be attractive for investors even now if appropriate batteries are selected for ESSs applications. Valve regulated lead acid batteries has a lower cost of initial investment, which is suitable for the situations that are sensitive to the initial investment cost. Lithium iron phosphate (LiFePO4, LFP) battery can be applied in the situations with a high requirement for service life. While zinc-air batteries still have great application prospects to cope with resource depletion due to excellent performance, low cost and low pollution. The current policy debate should therefore be refocused so as to promote technological development and to encompass the removal of such barriers.

This paper reports an epitaxial lift-off (ELO) method that uses water-soluble MgTe to obtain free-standing single-crystal CdTe/MgCdTe double-heterostructure (DH) thin films from samples grown monolithically on lattice-matched InSb substrates. Photoluminescence measurements on as-grown and free-standing films reveal that the optical quality of the DH survives ELO. This method potentially enables substantial increases in the conversion efficiencies of thin-film solar cells through enhancement of the photon-recycling effect. This process holds promise in multijunction PV applications that considers the integration of a 1.7-eV MgCdTe top cell and a crystalline Si bottom cell to form a tandem device with efficiency potentially higher than 30%. Additionally, the method can be applied to other families of devices, such as infrared photodetectors.

Alkaline zinc–air batteries are promising energy storage technologies with the advantages of low cost, ecological friendliness, and high energy density. However, the rechargeable zinc–air battery has not been used on a commercial scale because the zinc electrode suffers from critical problems such as passivation, dendrite growth, and hydrogen evolution reaction, which limit the practical applications of zinc–air batteries. Herein, the Perspective summaries the solutions to minimize the negative effects of zinc electrodes on discharge performance, cycling life, and shelf life. The future direction of academic research based on current studies of the existing challenges is proposed.

Flexible zinc-air batteries (ZABs) have been considered as one of the most outstanding energy storage devices for flexible and portable electronics because of their superior energy density and environmental friendliness. As the "blood" of flexible ZABs, electrolytes play a significant role in determining their performance, such as discharge working time, cycling property, and shelf life. Herein, a novel polymer electrolyte based on quaternary ammonium hydroxides is first applied in flexible zinc-air batteries. Tetraethylammonium hydroxide (TEAOH) is innovatively used as the ionic conductor with poly(vinyl alcohol) (PVA) as the polymer host in the polymer electrolyte and exhibits a good water retention capability, resulting in not only a good shelf life but also a good working life of the flexible zinc-air batteries. The fabricated polymer electrolyte maintains its high ionic conductivity of 30 mS cm

Summary: CO2 circular economy is urgently calling for the effective large-scale CO2 reutilization technologies. The reverse water-gas shift (RWGS) reaction is the most techno-economically viable candidate for dealing with massive-volume CO2 via downstream mature Fischer-Tropsch and methanol syntheses, but the desired groundbreaking catalyst represents a grand challenge. Here, we report the discovery of a nano-intermetallic InNi3C0.5 catalyst, for example, being particularly active, selective, and stable for the RWGS reaction. The InNi3C0.5(111) surface is dominantly exposed and gifted with dual active sites (3Ni-In and 3Ni-C), which in synergy efficiently dissociate CO2 into CO* (on 3Ni-C) and O* (on 3Ni-In). O* can facilely react with 3Ni-C-offered H* to form H2O. Interestingly, CO* is mainly desorbed at and above 400°C, whereas alternatively hydrogenated to CH3OH highly selectively below 300°C. Moreover, this nano-intermetallic can also fully hydrogenate CO-derived dimethyl oxalate to ethylene glycol (commodity chemical) with high selectivity (above 96%) and favorable stability. : Chemical Reaction; Catalysis; Nanomaterials Subject Areas: Chemical Reaction, Catalysis, Nanomaterials

A hollow-B-ZSM-5/SS-fiber catalyst is developed through alkali leaching of the full-silica core of the silicalite-1@B-ZSM-5 in situ structured onto a thin-felt stainless-steel fiber (20 μm SS-fiber), which is synthesized by a seed-assisted dry-gel vapor-phase transport method. As-obtained catalyst shows marked improvement in the mesoporosity-dependent diffusion (by o-xylene diffusion measurement). Boron incorporation is essential for preventing the framework dealumination during alkali leaching treatment due to the increased framework negative charges. The hollow-B-ZSM-5/SS-fiber catalyst shows remarkable stability improvement in the methanol-to-propylene (MTP) reaction because of the enhanced diffusion of the nano-hollow-structure and the boron-incorporation stabilized framework aluminum. A boron-free hollow-ZSM-5/SS-fiber is also obtainable with the textural properties comparable to the hollow-B-ZSM-5/SS-fiber but shows undesired degeneration of the tetra-coordinated aluminum. The preferential generation of coke in the micropores of the hollow-ZSM-5/SS-fiber causes a rapid deactivation even compared to the parent silicalite-1@ZSM-5/SS-fiber, due to the existence of extra-framework aluminum.

The rapid advancement of flexible and wearable electronic devices drives the need for flexible batteries, and zinc–air batteries (ZABs) have attracted extensive interest due to their extremely high theoretical energy density, eco-friendliness and low cost. However, the use of conventional alkaline ZABs is significantly restricted by corrosion and dendrite growth at the Zn anode and fast carbonate formation of the electrolyte. Herein, we report an emerging type of ZAB that uses a near-neutral gel polymer electrolyte (neutral GPE) with good water retention and high ionic conductivity; this ZAB system is more environmentally friendly and less corrosive than alkaline electrolytes, thus potentially avoiding carbonation problems and mitigating corrosion issues. Furthermore, an integrated nanoporous air cathode with an enlarged interfacial contact area and catalytic sites is utilized, and it demonstrates excellent flexibility and high strength. Due to these advantages, the assembled neutral GPE-based flexible ZABs exhibit a prolonged cycle life of 70 h in the fresh state and after being packaged for 10 days, indicating a remarkable battery life performance. Furthermore, the ZABs can be fabricated in customized shapes and sizes to satisfy the space and energy demands of a variety of applications, and they can operate without degraded battery performance under bending conditions and even during the tailoring process.

Metal–air batteries (MABs), which possess exceptionally high energy density and exhibit other ideal features such as low cost, environmental benignity and safety, are regarded as promising candidates for the next generation of power sources. The performance of MABs and the challenges involved in these systems are primarily related to metal electrodes. In the present work, different types of MABs are overviewed from the perspective of the metal electrodes. Most metal electrodes that have been studied in recent years are reviewed, among which Zn, Al, Mg and Fe are highlighted. The advantages and disadvantages of each system are presented, and recent advances that address challenges such as corrosion, passivation and dendrite growth are introduced. In addition, investigations focused on revealing interactions between the metal electrodes and electrolytes or exploring electrolytes to improve the performance of metal electrodes are also discussed. Finally, a general perspective on the current situation of this field and on future research directions is provided.

The wet-chemical technique has been widely applied in material synthesis. In recent years, high throughput (HT) technique has shown its potential in parallel synthesis and the investigation of synthesis parameters. However, traditional ways of HT parallel synthesis require costly equipment and complex operating procedures, restricting their further applications. In this paper, we prepared a cost-effective and timesaving microfluidic-based composition and temperature controlling platform to carry out HT wet-chemical synthesis in a facile and automated workflow. The platform uses a microfluidic chip to generate 20-level concentration gradients of the two reagents and uses 100-channel reactor arrays for wet-chemical synthesis with 5-level temperature gradients. Scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) were applied to characterize Co-Ni bimetallic powder materials synthesized under 100 different reaction conditions. X-ray photoelectron spectroscopy (XPS) was conducted to confirm the oxidation state of the products. This platform not only enables one-step determination of the minimum reaction temperature required for a wet-chemical system but also provides a significant increase in efficiency compared with the traditional wet-chemical approach. The microfluidic-based composition and temperature controlling platform shows promise in facile, efficient, and low-cost HT wet-chemical synthesis of materials.

As consumers' requirements for delivery speed and service quality become higher and higher and demand for terminal delivery is increasingly diversified, urban instant delivery has become a development trend under the current new retail model. The instant delivery problem with commitment is studied. To improve the operability and usability, two algorithms strictly abiding by the time commitment to improve customer service satisfaction are proposed as follows. In the first algorithm, the center-of-gravity clustering method is used to select the distribution route for the customer, that is, the nearest distribution route is selected as the insertion route after calculating the distance from the new customer to the center of gravity of the existing distribution route. Then the nearest insertion algorithm is applied to insert the customer into the selected route without violating the time commitment to all customers. In the second algorithm, based on the principle of first-come-first-served, the first departure route is selected, and the customer is inserted after the last existing customer of the selected route. Finally, the effectiveness of the two algorithms are verified with the known benchmarks. It's found that the first algorithm performs better than the second one with a shorter total traveling distance and a lower error rate.

Since the Paris Agreement came into effect in 2016, governments worldwide have established goals for future carbon emission reduction. Enterprises and governments have begun to pay attention to the management of carbon emission. This study explored the dynamic relationship between business growth and carbon emission performance by constructing and using a time series model to predict the trend of carbon emission. The time series method (ADF unit root test, cointegration test and VAR model etc.) was adopted to investigate 805 companies listed on the Taiwan Stock Exchange from 2012 to 2017 as the sample of this study. The carbon emission performance variables include: total carbon emission, annual increase of carbon emission, and annual increase rate of carbon emission. The business growth variables include: growth rate, stability of growth, and years of establishment. The results showed a long-term dynamic relationship between business growth and carbon emission performance. Therefore, using the time series method can assist enterprises in developing green strategies, strengthen carbon emission prediction and management capacities, reduce operating costs and risks, and actively achieve the ideal of sustainable development.

Massive self-compacting concrete pumped in steel tube columns has been used more and more widely in super high-rise buildings and bridge engineering at present. The early-age expansion and shrinkage performance of its core mass concrete is an important index to ensure the stress state of triaxial compression and structural safety. However, no relevant reports have been found. In view of the actual building with the height of 265.15 meters, the early-age expansion and shrinkage tests of the massive self-compacting concrete pumped in full-scale columns with the height of 12.54 m and 12.24 m and diameter of 1.3 m and 1.6 m were carried out by means of strain gauges embedded in concrete-filled steel tubes (CFSTs). The early-age variation regularity of the vertical and horizontal expansion and shrinkage strains for the core concrete with the diameter of steel tube, development time, temperature, the pouring pressure, expansion stress, and so on is given. The calculation model of its early-age deformation strains is presented in this paper, which is in good agreement with the experimental results. It provides the basis of experimental and theoretical analyses for shrinkage compensation of massive self-compacting concrete pumped in steel tube columns.

Zn2SnO4 nanotubes have been fabricated via a solution approach with the aiding of anodic aluminum oxide template. Microstructure analysis reveals that the as-prepared Zn2SnO4 nanotubes are polycrystalline and cubic spinel structured. Zn2SnO4 nanowires can also be successfully synthesized by prolonging the reaction time without changing other condition. A formation mechanism of Zn2SnO4 nanostructures has been proposed based on heterogeneous nucleation on AAO template pore walls. The photocatalytic activity study indicated that Zn2SnO4 nanotubes have a higher efficiency than nanowires. This may be induced by their hollow tube structure with larger specific surface area and more photocatalytic active sites.

In this critical Review we focus on the evolution of the hybrid ion capacitor (HIC) from its early embodiments to its modern form, focusing on the key outstanding scientific and technological questions that necessitate further in-depth study. It may be argued that HICs began as aqueous systems, based on a Faradaic oxide positive electrode (e.g., Co3O4, RuOx) and an activated carbon ion-adsorption negative electrode. In these early embodiments HICs were meant to compete directly with electrical double layer capacitors (EDLCs), rather than with the much higher energy secondary batteries. The HIC design then evolved to be based on a wide voltage (∼4.2 V) carbonate-based battery electrolyte, using an insertion titanium oxide compound anode (Li4Ti5O12, LixTi5O12) versus a Li ion adsorption porous carbon cathode. The modern Na and Li architectures contain a diverse range of nanostructured materials in both electrodes, including TiO2, Li7Ti5O12, Li4Ti5O12, Na6LiTi5O12, Na2Ti3O7, graphene, hard carbon, soft carbo...

A promising thin-felt stainless-steel-fiber (SS-fiber) structured hollow-ZSM-5/SS-fiber catalyst is developed through alkali leaching of the full-silica core from the silicalite-1@ZSM-5/SS-fiber. A silicalite-1 seeded dry-gel/SS-fiber is obtained by dip-coating technique and is then transformed into the silicalite-1@ZSM-5/SS-fiber (overall SiO 2 /Al 2 O 3 molar ratio of 93) via seed-assisted dry gel conversion method. Such catalyst shows marked enhancement of mesoporosity development because of the abundant hollow structures left behind after the silicalite-1 core removal by alkali treatment in a mild Na 2 CO 3 media. The effect of alkali-treated time length on catalyst structure, textural and acidic properties as well as methanol-to-propylene (MTP) performance is systematically investigated. As-obtained catalyst, with well-maintained Bronsted acid sites after alkali treatment, shows hollow-structure-dependent stability improvement in the MTP and n-hexane cracking processes due to markedly enhanced diffusion.

A series of thin-felt SS-fiber@HZSM-5 catalysts are fabricated via the seed-assisted vapor-phase transport (VPT) method. The crystal size and mesoporosity of zeolite shell are controllably tuned toward enhanced diffusion by increasing the silicalite-1 seeding gel (SG) amount used. The microstructured catalyst obtained with a high SG amount of 50% contains a smaller crystal size of ∼70 nm and higher mesopore volume of 0.21 cm3 gzeolite−1, which markedly prolonged single-run lifetime with a remarkable decrease in the coking rate in the MTP process. The adverse effect of non-uniform aluminum in the zeolite shell on the MTP stability is revealed. The use of aluminum-containing SG to replace the pure-silica one makes the acid sites of as-obtained ZSM-5 mounted on SS-fiber distributed homogeneously thereby leading to a marked suppression of hydrogen transfer, and as a result, the catalyst single-run lifetime is further increased by ∼40%. This promising SS-fiber@HZSM-5 catalyst is stable for at least 1600 h (>94% conv.) with a high propylene selectivity of ∼36% at 450 °C using a WHSV of 1 h−1 for a feed of MeOH/H2O molar ratio of 1:1, by taking advantage of improved diffusion from mesoporosity development and uniform aluminum distribution as well as our distinctive microfibrous-engineered design.

Intercalation compounds form the basis of essentially all lithium rechargeable batteries. They exhibit a wide range of electronic and crystallographic structures. The former varies from metallic conductors to excellent insulators. The latter often have layer structures or have open tunnel structures that can act as the hosts for the intercalation of a wide range of metal cation and other guest species. They are fascinating materials with almost infinitely variable properties, with the crystal structure controlling the identity and the amount of the guest species that may be intercalated and subsequently removed. The electronic structure controls not only the degree of electron transfer to the host, but also defines the degree of the electrostatic interactions a mobile ion experiences; thus, a metallic host will provide a minimizing of those interactions, whereas in an ionic lattice the interactions will be much greater and the mobile ion will experience a much higher activation energy for motion. This becomes more important for multivalent cations such as Mg

Recent advances in materials syntheses have enabled e-LiVOPO4 to deliver capacities approaching, and in some cases exceeding the theoretical value of 305 mA h g−1 for 2Li intercalation, despite its poor electronic and ionic conductivity. However, not all of the capacity corresponds to the true electrochemical intercalation/deintercalation reactions as evidenced upon systematic tracking of V valence through combined operando and rate-dependent ex situ X-ray absorption study presented herein. Structural disorder and defects introduced in the material by high-energy ball milling impede kinetics of the high-voltage V5+/V4+ redox more severely than the low-voltage V4+/V3+ redox, promoting significant side reaction contributions in the high-voltage region, irrespective of cycling conditions. The present work emphasizes the need for nanoengineering of active materials without compromising their bulk structural integrity in order to fully utilize high-energy density of multi-electron cathode materials.

Surfactin, a lipopeptide produced by Bacillus species, has been used for the oral delivery of insulin. In this study, another lipopeptide of iturin was tested for its ability to orally delivery insulin alone or plus surfactin. Iturin could form co-precipitate with insulin at acidic pH values. After treatment by ultrasonification, the structure of coprecipitate was destroyed that led to a significant decrease in hypoglycemic effect after oral administration. Iturin weakly binds to (Kd = 257 μM) and induce insulin structure more compact that is favorable for insulin uptake by the intestine. After being coated with Acryl-Eze by lyophilization, the coprecipitate formed the spherical enteric-coated insulin microparticles delivered by iturin with a relative oral bioavailability of 6.84% in diabetic mice. For further improving oral hypoglycemic effect, surfactin was added to form the spherical enteric-coated insulin microparticles in a formulation containing insulin, Acryl-Eze, iturin and surfactin at a ratio of 1:1:0.5: 0.5 (w/w), with an insulin encapsulation efficiency of 66.22%. The enteric-coated insulin microparticles delivered by iturin plus surfactin showed a classical profile for controlled release in the intestine with a relative bioavailability of 7.67% after oral administration, which could effectively control the postprandial blood glucose at a level about 50% of the initial one just like the subcutaneous injection. Collectively, iturin plus surfactin is more efficient for oral delivering insulin than the sole one, and the resultant enteric-coated insulin microparticles are potential for the development of oral insulin to control postprandial blood glucose in diabetic patients.

CO2 electroreduction (CO2 RR) to CO is promising for the carbon cycle but still remains challenging. Au is regarded as the most selective catalyst for CO2 RR, but its high cost significantly hinders its industrial application. Herein, the bimetallic CuInSe2 is found to exhibit an Au-like catalytic feature: i) the interaction of Cu and In orbitals induces a moderate adsorption strength of CO2 RR intermediates and favors the reaction pathway; and ii) the hydrogen evolution is energetically unfavorable on CuInSe2 , as a surface reconstruction along with high energy change will occur after hydrogen adsorption. Furthermore, the Se vacancy is found to induce an electron redistribution, slightly tune the band structure, and optimize the CO2 RR route of bimetallic selenide. Consequently, the Se-defective CuInSe2 (V-CuInSe2 ) achieves a highly selective CO production ability that is comparable to noble metals in aqueous electrolyte, and the V-CuInSe2 cathode shows a satisfactory performance in an aqueous Zn-CO2 cell. This work demonstrates that designing cost-effective catalysts with noble-metal-like properties is an ideal strategy for developing efficient electrocatalysts. Moreover, the class of transition bimetallic selenides has shown promising prospects as active and cost-effective electrocatalysts owing to their unique structural, electronic, and catalytic properties.

A novel photoelectrochemical (PEC) biosensor was constructed for DNA hydroxymethylation detection based on Bi4NbO8Cl/PTC-NH2 heterojunction and Fe-MIL-88NH2, where Bi4NbO8Cl/PTC-NH2 was employed as photoactive material and Fe-MIL-88NH2 was adopted as artificial hydrogen peroxide mimic enzyme. Based on the structure of hydroxymethylated cytosine in DNA sequence, 5-hydroxymethyl-2’-deoxycytidine (5hmdC) was employed as detected target molecule for the first time using PEC technique. After Bi4NbO8Cl/PTC-NH2 heterojunction was modified on the substrate electrode, thioglycolic acid (TGA) was captured by forming amide bond, where the sulfhydryl group (-SH) of TGA was employed as the specific recognition of 5hmdC. Under M. HhaI catalysis, the −CH2OH of 5hmdC reacted selectively with the –SH. Finally, Fe-MIL-88NH2 was modified on the electrode based on the crosslinker of 4-formylphenylboronic acid (FPBA), where FPBA possessed two active groups of formyl and boronic acid group, reacting with glycosyl of 5hmdC and amino of Fe-MIL-88NH2. Under the catalysis effect of Fe-MIL-88NH2, the insoluble substance was produced on the surface of electrodes, resulting in distinct lessening of PEC response. Under optimal conditions, the photocurrent shows a linear relationship with the logarithm value of 5hmdC concentration from 0.01-100 nM with a low detection limit of 6.48 pM. More importantly, this method can be applied to investigate the influence of exogenous phytohormone on 5hmdC content in the genomic DNA of rice seedling roots and leaves.

An integrated cobalt oxide catalyst supported on silica (Co3O4/SiO2) packed in the lumen of tubular alumina (Al2O3) membrane was designed to realize a Fenton-like oxidation coupling with ultrafiltration water treatment technology to remove persistent and hazardous pollutants. We employed a selection of SiO2 support materials with a range micro/mesostructures to immobilize the Co3O4 catalyst. These were evaluated and screened to achieve the highest pollutant decolorization rate and maximum decolorization efficiency. Then, an integrated catalyst-membrane was developed as proof-of-concept for advanced water treatment. Batch degradation results showed acid orange 7 dye (AO7) was effectively removed using Co3O4 deposited on MCM-41 silica, with 97% decolorization efficiency achieved in 15 mins owing to the large surface area and high porosity of the MCM-41 support. In contrast, humic acid (HA) was relatively difficult to degrade using this catalyst, and was however found to inhibit AO7 degradation. The integrated catalyst-membrane successfully removed both AO7 and HA with only a 10% water flux reduction from 25.0 to 22.5 kg m−2 h−1 bar−1 with excellent co-pollutant removal rate of 99% over 40 h. Furthermore, the integrated catalyst-membrane also removed a range of organic pollutants (neutral red, tetracycline hydrochloride, oxytetracycline) achieving > 90% rejection and 30 kg m−2 h−1 bar−1. These results show that the integrated catalyst-membrane can effectively purify a binary pollutant mixture containing both hazardous dye and natural organic matter and other pharmaceutical chemicals whilst producing process water for recycling and reuse.

Microfibrous-structured SS-fiber@beta composites are synthesized by coupling dip-coating method with a seed-assisted dry-gel conversion method. The beta crystals in zeolite shell are formed by growth on the surface of pre-added beta seeds and TEAOH-induced nucleus. One interesting point is that this approach is working highly effectively and efficiently even at high dry gel SiO 2 /Al 2 O 3 ratio of 200 (corresponding to 207 in the beta zeolite shell). Such SS-fiber@beta composites show great potentials for the heat/mass transfer limited reactions due to their hierarchical porosity, small crystals, controllable acidity as well as our distinctive microfibrous-structured design.

Surfactin is a Bacillus-produced natural lipopeptide, which can overcome the epithelial cell barriers for orally delivering insulin, but its ability to promote uptake of insulin by the intestine need to be further improved for a higher oral bioavailability. Here, we designed and synthesized several surfactin variants to improve its ability for oral delivery of insulin. Firstly, we replaced Glu with Gln in surfactin for decreasing its negative charges, but found this replacement weakened its ability to orally delivery insulin. We further chemically synthesized surfactin variant by replacing its fatty acid chain (C15) with a shortened one (C14), and found this replacement did not influence its ability to orally deliver insulin. Lastly, we replaced its amino acids (Leu) with more hydrophobic ones (Ile), and found the replacement could significantly improve its ability to deliver insulin, with a maximal blood glucose decrease to 27.33% of the initial level and an insulin bioavailability of 18.25%. We also replaced its amino acids of Leu with Val, and Val with Ile, and found this replacement could also significantly improve its ability to deliver insulin with a maximal blood glucose decrease to 18.36% of the initial level and a high insulin bioavailability of 26.32% in diabetic mice. Further analysis by CD, we found the surfactin variants with more hydrophobic amino acid residuals significantly induced insulin from rigid (α-helix) to flexible structure (β-sheet and random coil), that is favorable for insulin to permeate across the intestine epithelial membrane. Collectively, surfactin variants with more hydrophobicity are very potential for delivery of insulin in the everyday control of blood glucose.

Uncertainty decrease is an important attribute during the risk elements transmission process, and the occurrence of risk elements may not be clear until all factors tend to be steady. To study the interrelation among risk elements and their occurrence mechanism, this paper makes an analogy between risk elements transmission effect and molecular motion of thermodynamics and defines the entropy system based on entropy theory to integrate the macroscopic transmission with the microcosmic entropy change. A hypothesis about the state of risk elements during the entropy reduction process is proposed. And a risk elements neural network is built to simulate the transmission effect with simulated annealing algorithm controlling the entropy reduction. With a practical example, the hypothesis is proved and the coming risk elements are forecasted. This shows the model with a fast convergence rate effectively combines risk elements and entropy, which can be widely applied in the risk early-warning management.

Selective adsorption and energy-saving regeneration are two important issues for adsorptive separation. However, it is impossible for traditional adsorbents with changeless pore properties to realize both of them. In this study, a strategy was proposed to design and fabricate a new generation of adsorbents via grafting the thermoresponsive polymers (TPs), namely, poly(N-isopropylacrymide) (PNIPAM), onto the pore surface of mesoporous silica SBA-15. The TPs disperse homogeneously in pore space and act as molecular switches which are reversibly closed or opened with the change of temperature. At the temperature of adsorption below the lower critical solution temperature (LCST), TPs are extended as a result of their extensive hydrogen bonding interactions with water and the molecular switches are closed. It is easier for smaller adsorbates to enter than larger ones, and the selective adsorption can be consequently realized. At the temperature of desorption (above LCST), TPs shrink owing to their hydrogen bon...

Single crystalline Cu 2 SnS 3 nanosheets with exposed (220) planes have been synthesized via a facial solvothermal solution chemical route. The solvent of ethylenediamine hindered the growth along the [110] direction and facilitated the formation of two dimensional nanostructures. Electrochemical performance of Cu 2 SnS 3 electrodes in sodium ion batteries was investigated. Cu 2 SnS 3 electrodes exhibit an initial sodiation capacity of 586 mAh/g and 178 mAh/g after 50 cycles. The electrochemical properties of Cu 2 SnS 3 nanosheets suggest it is a potential anode material for sodium ion batteries.

A novel solvothermal chemical route has been developed to synthesize Cu–Sb–S compound nanocrystals in a controllable manner. Cu3SbS4 and CuSbS2 nanocrystals can be selectively prepared by modifying the reaction temperature. The temperature dependent release of antimony from potassium antimonyl tartrate trihydrate faciliated the selective synthesis of Cu3SbS4 and CuSbS2. The bandgap is 1.0 eV for Cu3SbS4 nanocrystals and 1.45 eV for CuSbS2 nanocrystals. Semiconductors of Cu–Sb–S compounds with such band gaps are desirable for solar cell applications. The Cu3SbS4 and CuSbS2 nanocrystals both showed obvious photo-electric response, indicating their potential application as an active layer in thin-film solar cells.

Free-standing stainless-steel (SS)-fiber@meso-HZSM-5 core–shell catalysts engineered from micro- to macro-scale were highly efficiently synthesized via cost-effective steam-assisted crystallization (SAC) method. Impact of synthesis conditions on their morphology and textural/acidic properties was investigated by means of XRD, SEM, TEM, solid-state NMR, NH3-TPD, Py-IR and N2 physisorption. Single-run lifetime of such structured catalysts for MTP process was strongly dependent on their preparation conditions but slightly the product distribution. A volcano-like relationship for lifetime was observed against the SAC time, which was correlated well with the crystallization-time-dependent crystallinity, mesoporosity and crystal size. The promising SS-fiber@meso-HZSM-5 was the one obtained after the SAC for 12 h, which delivered a prolonged single-run lifetime of 620 h with a high propylene selectivity of ∼42% at 450 °C using a methanol weight hourly space velocity (WHSV) of 1 h–1, as the result of high crystal...

A microstructured SS-fiber@ZSM-5 core–shell catalyst engineered from micro- to macro-scale in one step is developed through a cost-effective and high-efficiency vapor-phase transport (VPT) synthesis. A sinter-locked three-dimensional microfibrous-structure consisting of 15 vol% stainless steel fibers (SS-fiber, 20 μm dia.) was dip-coated with a synthesis gel containing silicalite-1 and subsequently steamed at 180 °C using ethylenediamine (EDA) solution. The as-synthesized ZSM-5 shell contains fine coffin-shaped crystals and small grains with remarkable intercrystalline mesopores derived from the initial aggregated aluminosilicate particles while the mesopore size is ever-changing with the progression of the crystallization. The catalyst lifetime for the MTP reaction shows a volcano-like evolution against the VPT time length, which correlates well with the crystallization-time-dependent amount of Bronsted acid and mesoporosity. The most promising SS-fiber@HZSM-5 catalyst is the one obtained via VPT synthesis for 120 h, with a high shell diffusion coefficient of 1.6 × 10−14 m2 s−1, delivering a prolonged single-run lifetime of 45 h with a high propylene selectivity of ∼46.9% at 450 °C at a high methanol weight hourly space velocity (WHSV) of 10 h−1.

We created Immense Surface Area Carbons (ISACs) by a novel heat treatment that stabilized the micelle structure in a biological based precursor prior to high temperature combined activation – pyrolysis. While displaying a morphology akin to that of commercial activated carbon, ISACs contain an unparalleled combination of electrochemically active surface area and pore volume (up to 4051 m2 g−1, total pore volume 2.60 cm3 g−1, 76% small mesopores). The carbons also possess the benefit of being quite pure (combined O and N: 2.6–4.1 at%), thus allowing for a capacitive response that is primarily EDLC. Tested at commercial mass loadings (∼10 mg cm−2) ISACs demonstrate exceptional specific capacitance values throughout the entire relevant current density regime, with superior rate capability primarily due to the large fraction of mesopores. In the optimized ISAC, the specific capacitance (Cg) is 540 F g−1 at 0.2 A g−1, 409 F g−1 at 1 A g−1 and 226 F g−1 at a very high current density of 300 A g−1 (∼0.15 second charge time). At intermediate and high currents, such capacitance values have not been previously reported for any carbon. Tested with a stable 1.8 V window in a 1 M Li2SO4 electrolyte, a symmetric supercapacitor cell yields a flat energy–power profile that is fully competitive with those of organic electrolyte systems: 29 W h kg−1 at 442 W kg−1 and 17 W h kg−1 at 3940 W kg−1. The cyclability of symmetric ISAC cells is also exceptional due to the minimization of faradaic reactions on the carbon surface, with 80% capacitance retention over 100 000 cycles in 1 M Li2SO4 and 75 000 cycles in 6 M KOH.

We created a unique sodium ion battery (NIB, SIB) cathode based on selenium in cellulose-derived carbon nanosheets (CCNs), termed Se-CCN. The elastically compliant two-dimensional CCN host incorporates a high mass loading of amorphous Se (53 wt%), which is primarily impregnated into 1 cm3 g−1 nanopores. The results in facile sodiation kinetics due to short solid-state diffusion distances and a large charge transfer area of the nanosheets were established. The architecture also leads to an intrinsic resistance to polyselenide shuttle and to disintegration/coarsening. As a Na half-cell, the Se-CCN cathode delivers a reversible capacity of 613 mA h g−1 with 88% retention over 500 cycles. The exceptional stability is achieved by using a standard electrolyte (1 M NaClO4 EC-DMC) without secondary additives or high salt concentrations. The rate capability is also superb, achieving 300 mA h g−1 at 10C. Compared to recent state-of-the-art literature, the Se-CCN is the most cyclically stable and offers the highest rate performance. As a Se–Na battery, the system achieves 992 W h kg−1 at 68 W kg−1 and 384 W h kg−1 at 10144 W kg−1 (by active mass in a cathode). We are the first to fabricate and test a Se-based full NIB, which is based on Se-CCN coupled to a Na intercalating pseudographitic carbon (PGC) anode. It is demonstrated that the PGC anode increases its structural order in addition to dilating as a result of Na intercalation at voltages below 0.2 V vs. Na/Na+. The {110} Na reflections are distinctly absent from the XRD patterns of PGC sodiated down to 0.001 V, indicating that the Na metal pore filling is not significant for pseudographitic carbons. The battery delivers highly promising Ragone chart characteristics, for example yielding 203 and 50 W h kg−1 at 70 and 14000 W kg−1 (via total material mass in the anode and cathode).

Heterostructured ZnS/InP nanowires, composed of single-crystalline ZnS nanowires coated with a layer of InP shell, were synthesized via a one-step chemical vapor deposition process. As-grown heterostructured ZnS/InP nanowires exhibited an ultrahigh Ion/Ioff ratio of 4.91 × 103, a high photoconductive gain of 1.10 × 103, a high detectivity of 1.65 × 1013 Jones and high response speed even in the case of very weak ultraviolet light illumination (1.87 μW cm-2). The values are much higher than those of previously reported bare ZnS nanowires owing to the formation of core/shell heterostructures. Flexible ultraviolet photodetectors were also fabricated with the heterostructured ZnS/InP nanowires, which showed excellent mechanical flexibility, electrical stability and folding endurance besides excellent photoresponse properties. The results elucidated that the heterostructured ZnS/InP nanowires could find good applications in next generation flexible optoelectronic devices.

Next-generation wearable and portable electronic devices require the development of flexible energy-storage devices with high energy density and low cost. Over the past few decades, flexible zinc–air batteries (FZABs), characterized by their extremely high theoretical energy density from consuming oxygen in air and low cost, have been regarded as one of the most promising power supplies. However, their unique half-open structure poses great challenges for the environmental stability of their components, including the electrolyte and electrodes. As an important ionic conductor, the poly(vinyl alcohol) (PVA)–KOH gel polymer electrolyte (GPE) has been widely utilized in FZABs. To date, most studies have focused on investigations of the electrode, electrocatalyst materials and battery configuration, while very few have paid attention to the influence of the environment on the electrolyte and the corresponding FZAB performance. Herein, for the first time, the environmental stability of PVA–KOH GPE, such as dimensional stability and water and ionic conductivity retention capability, for FZABs in ambient air has been thoroughly studied. Moreover, the properties of the assembled FZABs in terms of cycling stability, discharge performance and power output are investigated. This report aims to play a leading role in examining the environmental stability of electrolytes in FZABs, which is critical for their practical applications.

This paper reports a comparison study of open-circuit voltage (VOC) in three kinds of CdTe/MgCdTe doubleheterostructure solar cells featuring p-type a-Si:H, ZnTe:As or ZnTe:Cu as hole contact layers, respectively. Devices with p-type a-Si:H demonstrated a record V OC of 1.1 V while the V OC of the devices with p-type ZnTe:As and ZnTe:Cu drop below 0.9 V C-V measurements and time-resolved photoluminescence measurements reveal built-in voltages (V bi ) of 1.20 V, 1.23 V and 0.90 V, and minority carrier lifetime 300 ns, 52 ns and 170 ns for devices with different types of hole contacts, respectively. For the devices with a ZnTe:As layer, an increase in nonradiative recombination rate and a reduction in V OC are observed due to the misfit dislocations at the ZnTe/MgCdTe interface. The low V OC seen in the devices with a ZnTe: Cu layer is mainly limited by their low V bi .

Directly harvesting solar energy for battery charging represents an ultimate solution toward low-cost, green, efficient and sustainable electrochemical energy storage. Here, we design a sunlight promotion strategy into rechargeable zinc–air battery with significantly reduced charging potential below the theoretical cell voltage of zinc–air batteries. The sunlight-promoted zinc–air battery using BiVO4 or α-Fe2O3 air photoelectrode achieves a record-low charge potential of ~1.20 and ~1.43 V, respectively, under illumination, which is lowered by ~0.5–0.8 V compared to the typical charge voltage of ~2 V in conventional zinc–air battery. The band structure and photoelectrochemical stability of photoelectrodes are found to be key factors determining the charging performance of sunlight-promoted zinc–air batteries. The introduction of photoelectrode as an air electrode opens a facile way for developing integrated single-unit zinc–air batteries that can efficiently use solar energy to overcome the high charging overpotential of conventional zinc–air batteries., The authors here report a sunlight-promoted rechargeable zinc–air battery in which photoelectrode is used as the air electrode to substantially lower the charge potential under illumination. Notably, the battery can be initially charged with an extremely low voltage of ~1.20 V.

The most challenging issue in the development of metal-air batteries is the insufficient catalytic activity of the cathode toward oxygen evolution and reduction reactions (OER/ORR). Metal-organic frameworks (MOFs) and MOF-based electrocatalysts have drawn considerable attention for the replacement of noble-metal electrocatalysts. Here, the rational design and synthesis of bimetallic CoNi-MOF nanosheets/reduced graphene oxide (rGO) hybrid electrocatalysts is reported. The CoNi-MOF nanosheets were in situ grown onto rGO assisted by the surfactant modulation. The newly developed CoNi-MOF/rGO hybrids, consisting of homogeneously distributed nanosheets encapsulated by rGO, display excellent electrocatalytic activities toward OER and ORR. The much improved bifunctional catalytic performance is ascribed to the synergy among the CoNi-MOF nanosheets and rGO, the abundant exposed active sites, and the enhanced electron conductivity. Moreover, the rechargeable Zn-air batteries with CoNi-MOF/rGO-based air electrodes display high energy density and cycling stability, demonstrating the great potential as advanced bifunctional electrocatalysis in electronic devices.

Sulfur-rich carbons are minimally explored for potassium-ion batteries (KIBs). Here, a large amount of S (38 wt%) is chemically incorporated into a carbon host, creating sulfur-grafted hollow carbon spheres (SHCS) for KIB anodes. The SHCS architecture provides a combination of nanoscale (≈40 nm) diffusion distances and CS chemical bonding to minimize cycling capacity decay and Coulombic efficiency (CE) loss. The SHCS exhibit a reversible capacity of 581 mAh g-1 (at 0.025 A g-1 ), which is the highest reversible capacity reported for any carbon-based KIB anode. Electrochemical analysis of S-free carbon spheres baseline demonstrates that both the carbon matrix and the sulfur species are highly electrochemically active. SHCS also show excellent rate capability, achieving 202, 160, and 110 mAh g-1 at 1.5, 3, and 5 A g-1 , respectively. The electrode maintains 93% of the capacity from the 5th to 1000th cycle at 3 A g-1 , with steady-state CE being near 100%. Raman analysis indicates reversible breakage of CS and SS bonds upon potassiation to 0.01 V versus K/K+ . The galvanostatic intermittent titration technique (GITT) analysis provides voltage-dependent K+ diffusion coefficients that range from 10-10 to 10-12 cm2 s-1 upon potassiation and depotassiation, with approximately five times higher coefficient for the former.

Glycerol is a byproduct from the biodiesel manufacturing. Glycerol dehydration into more valuable acrolein is desirable and essential since it improves the economics of the biodiesel production and offers a sustainable route to replace the market favorite chemical from petroleum process. Zeolites with the dominant and uniform Brønsted acid sites have been widely used in glycerol dehydration since Brønsted acid sites are flexible and interacting with the center hydroxyl of glycerol toward acrolein production. In this research, microstructured ZSM-11 catalysts have been developed by direct growth of zeolite crystals on a macroscopic three-dimensional (3D) network of sinter-locked stainless steel microfibers. It showed remarkable stability and acrolein selectivity improvement compared to conventional ZSM-11 zeolite, due to the short residence time to limit the secondary reactions and enhanced mass transfer to minimize the coke formation. The acidity of zeolites has been optimized via tuning the SiO2/Al2O3 ratios in a wide range from 78 to 283. The highest glycerol conversions and acrolein selectivity were observed over the catalyst with a SiO2/Al2O3 molar ratio of 131. A higher temperature of 300 °C was necessary to achieve better catalytic conversion and improve the acrolein formation. At the high flow of carrier gas, the coke formation was suppressed due to the enhanced diffusion of large products out of the zeolite pores.

This paper reports an improved epitaxial lift-off (ELO) technology for monocrystalline CdTe/MgCdTe double-heterostructure (DH) thin films using water-soluble and nearly lattice-matched MgTe as a sacrificial layer. Employing hard-baked photoresist as the superstrates with appropriate surface tension, the lift-off thin films show smooth and flat surfaces, confirmed by atomic-force microscopy profiles. Photoluminescence (PL) measurements reveal further enhancement of the light extraction from the ELO thin films with a coated Ag back reflective mirror. The increased PL intensity also confirms that the CdTe/MgCdTe DHs maintain high optical quality after ELO. External luminescence quantum efficiency ( η ext) is quantitatively measured and used to calculate the implied open-circuit voltage (iVOC). A 0.5-μm-thick lift-off CdTe/MgCdTe DH with a back mirror demonstrates an η ext value of 5.35% and an iVOC value of 1.152 V. The devices based on this structure are also expected to have an improved fill factor and a short-circuit current density (JSC) of 24.7 mA/cm2 according to the simulation results, promising to achieve CdTe solar cells with a record power conversion efficiency.