Blue Energy Collection toward All‐Hours Self‐Powered Chemical Energy Conversion

The conversion and transmission of blue energy in the ocean are critical issues. By employing triboelectric nanogenerators (TENGs), blue energy can be harvested but the corresponding electricity transmission and storage are still great challenges. In this work, an automatic high‐efficiency self‐powered energy collection and conversion system is proposed that converts blue energy to chemical energy. A gear‐driven unidirectional acceleration TENG is designed to convert disordered and low‐frequency water wave energy to low voltage and high current DC output. The output bias from the TENG can be used to drive a Ti–Fe₂O₃/FeNiOOH based photoelectrochemical cell under sunlight to produce hydrogen. Moreover, under the situation without sunlight, the self‐powered system can be automatically switched to another working state to charge a Co₃O₄ based lithium‐ion battery. The hydrogen production rate reaches to 4.65 µL min^‐1 under sunlight at the rotation speed of 120 rpm. The conversion efficiency of the whole system is calculated to be 2.29%. The system triggered by photoswitches can automatically switch between two working states with or without sunlight and convert the blue energy to either hydrogen energy or battery energy for easy storage and transmission, which widens the future applications for blue energy.     

Molten‐NaNH2 Densified Graphene with In‐Plane Nanopores and N‐Doping for Compact Capacitive Energy Storage

Capacitive carbons are attractive for energy storage on account of their superior rate and cycling performance over traditional battery materials, but they usually suffer from a far lower volumetric energy density. Starting with expanded graphene, a simple, multifunctional molten sodium amide treatment for the preparation of high‐density graphene with high capacitive performance in both aqueous and lithium battery electrolytes is reported. The molten sodium amide can condense the expanded graphene, lead to nitrogen doping and, what is more important, create moderate in‐plane nanopores on graphene to serve as ion access shortcuts in dense graphene stacks. The resulting high‐density graphene electrode can deliver a volumetric capacitance of 522 F cm^?3 in a potassium hydroxide electrolyte; and in a lithium‐ion battery electrolyte, it exhibits a gravimetric and volumetric energy density of 618 W h kg^?1 and 740 W h L^?1, respectively, and even outperforms commercial LiFePO₄.     

MXene‐on‐Paper Coplanar Microsupercapacitors

A simple and scalable direct laser machining process to fabricate MXene‐on‐paper coplanar microsupercapacitors is reported. Commercially available printing paper is employed as a platform in order to coat either hydrofluoric acid‐etched or clay‐like 2D Ti₃C₂ MXene sheets, followed by laser machining to fabricate thick‐film MXene coplanar electrodes over a large area. The size, morphology, and conductivity of the 2D MXene sheets are found to strongly affect the electrochemical performance due to the efficiency of the ion‐electron kinetics within the layered MXene sheets. The areal performance metrics of Ti₃C₂ MXene‐on‐paper microsupercapacitors show very competitive power‐energy densities, comparable to the reported state‐of‐the‐art paper‐based microsupercapacitors. Various device architectures are fabricated using the MXene‐on‐paper electrodes and successfully demonstrated as a micropower source for light emitting diodes. The MXene‐on‐paper electrodes show promise for flexible on‐paper energy storage devices.     

Heteroatom‐Doped and Oxygen‐Functionalized Nanocarbons for High‐Performance Supercapacitors

Electrochemical capacitors (best known as supercapacitors) are high‐performance energy storage devices featuring higher capacity than conventional capacitors and higher power densities than batteries, and are among the key enabling technologies of the clean energy future. This review focuses on performance enhancement of carbon‐based supercapacitors by doping other elements (heteroatoms) into the nanostructured carbon electrodes. The nanocarbon materials currently exist in all dimensionalities (from 0D quantum dots to 3D bulk materials) and show good stability and other properties in diverse electrode architectures. However, relatively low energy density and high manufacturing cost impede widespread commercial applications of nanocarbon‐based supercapacitors. Heteroatom doping into the carbon matrix is one of the most promising and versatile ways to enhance the device performance, yet the mechanisms of the doping effects still remain poorly understood. Here the effects of heteroatom doping by boron, nitrogen, sulfur, phosphorus, fluorine, chlorine, silicon, and functionalizing with oxygen on the elemental composition, structure, property, and performance relationships of nanocarbon electrodes are critically examined. The limitations of doping approaches are further discussed and guidelines for reporting the performance of heteroatom doped nanocarbon electrode‐based electrochemical capacitors are proposed. The current challenges and promising future directions for clean energy applications are discussed as well.     

Hospital Patient‐Care and Outside‐the‐Hospital Energy Profiles for Hemodialysis Services

Studies investigated the patient‐care (in‐hospital) and outside‐the‐hospital energy consumptions for delivering the hemodialysis (HD) service. A life cycle inventory methodology was used for this patient‐based analysis for two hospitals located in Wichita, Kansas. It was found that, for both hospitals, the actual HD machines consumed approximately 3.5 kilowatt‐hours (kWh) of electrical energy per HD, only 8% to 16% of the total energy used for delivering the HD service (in hospital). This increases to 9.6 to 28.9 kWh of hospital billable energy for the whole system of HD machine, auxiliaries, and dialysis water treatment. Converting these hospital direct electrical energy values to natural resource energy (nre) then adding the cradle‐to‐gate natural resource energy for the manufacturing and supply chain of all the HD consumables, the total is 78 to 149 kWh nre/HD. The nre measures all the direct fuel burned to generate energy and is thus directly related to emissions to the air, water, and land and is a direct secondary impact on public health from HD. The ratio of outside‐the‐hospital energy to direct hospital HD electrical energy consumption is 4:1 to 7:1, so a broader base exists for improvement than just the hospital.     

High‐Energy‐Density Foldable Battery Enabled by Zigzag‐Like Design

Flexible batteries, seamlessly compatible with flexible and wearable electronics, attract a great deal of research attention. Current designs of flexible batteries struggle to meet one of the most extreme yet common deformation scenarios in practice, folding, while retaining high energy density. Inspired by origami folding, a novel strategy to fabricate zigzag‐like lithium ion batteries with superior foldability is proposed. The battery structure could approach zero‐gap between two adjacent energy storage segments, achieving an energy density that is 96.4% of that in a conventional stacking cell. A foldable battery thus fabricated demonstrates an energy density of 275 Wh L^?1 and is resilient to fatigue over 45 000 dynamic cycles with a folding angle of 130°, while retaining stable electrochemical performance. Additionally, the power stability and resilience to nail shorting of the foldable battery are also examined.     

Paper‐Based Energy‐Storage Devices Comprising Carbon Fiber‐Reinforced Polypyrrole‐Cladophora Nanocellulose Composite Electrodes

Composites of polypyrrole (PPy) and Cladophora nanocellulose, reinforced with 8 μm‐thick chopped carbon filaments, can be used as electrode materials to obtain paper‐based energy‐storage devices with unprecedented performance at high charge and discharge rates. Charge capacities of more than 200 C g^?1 (PPy) are obtained for paper‐based electrodes at potential scan rates as high as 500 mV s^?1, whereas cell capacitances of ～60–70 F g^?1 (PPy) are reached for symmetric supercapacitor cells with capacitances up to 3.0 F (i.e.,0.48 F cm^?2) when charged to 0.6 V using current densities as high as 31 A g^?1 based on the PPy weight (i.e., 99 mA cm^?2). Energy and power densities of 1.75 Wh kg^?1 and 2.7 kW kg^?1, respectively, are obtained when normalized with respect to twice the PPy weight of the smaller electrode. No loss in cell capacitance is seen during charging/discharging at 7.7 A g^?1 (PPy) over 1500 cycles. It is proposed that the nonelectroactive carbon filaments decrease the contact resistances and the resistance of the reduced PPy composite. The present straightforward approach represents significant progress in the development of low‐cost and environmentally friendly paper‐based energy‐storage devices for high‐power applications.     

An Operando Mechanistic Evaluation of a Solar‐Rechargeable Sodium‐Ion Intercalation Battery

Solar‐intercalation batteries, which are able to both harvest and store solar energy within the electrodes, are a promising technology for the more efficient utilization of intermittent solar radiation. However, there is a lack of understanding on how the light‐induced intercalation reaction occurs within the electrode host lattice. Here, an in operando synchrotron X‐ray diffraction methodology is introduced, which allows for real‐time visualization of the structural evolution process within a solar‐intercalation battery host electrode lattice. Coupled with ex situ material characterization, direct correlations between the structural evolution of MoO₃ and the photo‐electrochemical responses of the solar‐intercalation batteries are established for the first time. MoO₃ is found to transform, via a two‐phase reaction mechanism, initially into a sodium bronze phase, Na_0.33MoO₃, followed by the formation of solid solutions, Na_xMoO₃ (0.33 < x < 1.1), on further photointercalation. Time‐resolved correlations with the measured voltages indicate that the two‐phase evolution reaction follows zeroth‐order kinetics. The insights achieved from this study can aid the development of more advanced photointercalation electrodes and solar batteries with greater performances.     

Nanostructured p‐n Junctions for Kinetic‐to‐Electrical Energy Conversion

Piezoelectric ZnO nanorods grown on a flexible substrate are combined with the p‐type semiconducting polymer PEDOT:PSS to produce a p‐n junction device that successfully demonstrates kinetic‐to‐electrical energy conversion. Both the voltage and current output of the devices are measured to be in the range of 10 mV and 10 μA cm^?2. Combining these figures for the best device gives a maximum possible power density of 0.4 mW cm^?3. Systematic testing of the devices is performed showing that the voltage output increases linearly with applied stress, and is reduced significantly by illumination with super‐band gap light. This provides strong evidence that the voltage output results from piezoelectric effects in the ZnO. The behavior of the devices is explained by considering the time‐dependent changes in band structure resulting from the straining of a piezoelectric material within a p‐n junction. It is shown that the rate of screening of the depolarisation field determines the power output of a piezoelectric energy harvesting device. This model is consistent with the behavior of a number of previous devices utilising the piezoelectric effect in ZnO.     

Synthesis and characterization of high quantum yield and oscillator strength 6‐chloro‐2‐(4‐cynophenyl)‐4‐phenyl quinoline (cl‐CN‐DPQ) organic phosphor for solid‐state lighting

A novel blue luminescent 6‐chloro‐2‐(4‐cynophenyl) substituted diphenyl quinoline (Cl‐CN DPQ) organic phosphor has been synthesized by the acid‐catalyzed Friedlander reaction and then characterized to confirm structural, optical and thermal properties. Structural properties of Cl‐CN‐DPQ were analyzed by Fourier transform infrared (FTIR), nuclear magnetic resonance (NMR) spectroscopy, X‐ray diffraction technique (XRD) and scanning electron microscopy (SEM) and energy dispersive analysis of X‐ray (EDAX) spectroscopy. FTIR spectra confirmed the presence of different functional groups and bond stretching. ¹H–NMR and ¹³C–NMR confirmed the formation of an organic Cl‐CN‐DPQ compound. X‐ray diffraction study provided its crystalline nature. The surface morphology of Cl‐CN‐DPQ was analyzed by SEM, while EDAX spectroscopy revealed the elemental analysis. Differential thermal analysis (TGA/DTA) disclosed its thermal stability up to 250°C. The optical properties of Cl‐CN‐DPQ were investigated by UV–vis absorption and photoluminescence (PL) measurements. Cl‐CN‐DPQ exhibits intense blue emission at 434 nm in a solid‐state crystalline powder with CIE co‐ordinates (0.157, 0.027), when excited at 373 nm. Cl‐CN‐DPQ shows remarkable Stokes shift in the range 14800–5100 cm^?1, which is the characteristic feature of intense light emission. A narrow full width at half‐maximum (FWHM) value of PL spectra in the range 42–48 nm was observed. Oscillator strength, energy band gap, quantum yield, and fluorescence energy yield were also examined using UV–vis absorption and photoluminescence spectra. These results prove its applications towards developing organic luminescence devices and displays, organic phosphor‐based solar cells and displays, organic lasers, chemical sensors and many more.     

Triboelectrification‐Enabled Self‐Charging Lithium‐Ion Batteries

Li‐ion batteries as energy storage devices need to be periodically charged for sustainably powering electronic devices owing to their limited capacities. Here, the feasibility of utilizing Li‐ion batteries as both the energy storage and scavenging units is demonstrated. Flexible Li‐ion batteries fabricated from electrospun LiMn₂O₄ nanowires as cathode and carbon nanowires as anode enable a capacity retention of 90% coulombic efficiency after 50 cycles. Through the coupling between triboelectrification and electrostatic induction, the adjacent electrodes of two Li‐ion batteries can deliver an output peak voltage of about 200 V and an output peak current of about 25 µA under ambient wind‐induced vibrations of a hexafluoropropene–tetrafluoroethylene copolymer film between the two Li‐ion batteries. The self‐charging Li‐ion batteries have been demonstrated to charge themselves up to 3.5 V in about 3 min under wind‐induced mechanical excitations. The advantages of the self‐charging Li‐ion batteries can provide important applications for sustainably powering electronics and self‐powered sensor systems.     

The Estrogen Antagonist EM‐652 and Dehydroepiandrosterone Prevent Diet‐ and Ovariectomy‐Induced Obesity

Objective: EM‐652 is a pure antiestrogen in human breast and uterine cancer cells that also reduces bone loss and plasma lipid levels in the rat. This study aimed to assess the ability of EM‐652, alone or with dehydroepiandrosterone (DHEA), to prevent obesity and related metabolic abnormalities induced by an obesity‐promoting diet and ovariectomy. Research Methods and Procedures: Female rats were fed a high‐sucrose, high‐fat (HSHF) diet, were left intact or ovariectomized (OVX), and were treated with EM‐652, DHEA, or both for 20 days. Variables of energy balance and determinants of lipid metabolism and insulin sensitivity were assessed. Results: The HSHF diet (vs. chow) and OVX both increased energy intake and gain, as well as energetic efficiency. Both EM‐652 and DHEA prevented diet‐ and OVX‐induced energy gain mainly by decreasing fat deposition, without being additive. The modest EM‐652‐induced increase in liver triglycerides of intact rats was prevented by its combination with DHEA. EM‐652, but not DHEA, decreased cholesterolemia. The HSHF diet and OVX reduced insulin sensitivity, an effect that was attenuated by EM‐652 and abrogated by DHEA and EM‐652+DHEA. Treatment with EM‐652, DHEA, or their combination abolished the diet‐ and OVX‐induced increase in adipose lipoprotein lipase activity that accompanied fat gain. Discussion: EM‐652 is an effective agent to prevent diet‐ and OVX‐induced obesity and its associated cardiovascular risk factors such as insulin resistance. The addition of DHEA prevents hepatic lipid accumulation and further ameliorates insulin sensitivity. The beneficial metabolic effects of such combined steroid therapy may, therefore, eventually prove to be clinically relevant.     

A Sodium‐Ion Battery with a Low‐Cost Cross‐Linked Gel‐Polymer Electrolyte

The design of a sodium‐ion rechargeable battery with an antimony anode, a Na₃V₂(PO₄)₃ cathode, and a low‐cost composite gel‐polymer electrolyte based on cross‐linked poly(methyl methacrylate) is reported. The application of an antimony anode, on replacement of the sodium metal that is commonly used in sodium‐ion half‐cells, reduces significantly the interfacial resistance and charge transfer resistance of a sodium‐ion battery, which enables a smaller polarization for a sodium‐ion full‐cell Sb/Na₃V₂(PO₄)₃ running at relatively high charge and discharge rates. The incorporation of the gel‐polymer electrolyte is beneficial to maintain stable interfaces between the electrolyte and the electrodes of the sodium‐ion battery at elevated temperature. When running at 60 °C, the sodium‐ion full‐cell Sb/Na₃V₂(PO₄)₃ with the gel‐polymer electrolyte exhibits superior cycling stability compared to a battery with the conventional liquid electrolyte.     

Red‐shifted emission from 1,2‐dioxetane‐based chemiluminescent reactions

Commercial chemiluminescent reagents emit across a broad portion of the electromagnetic spectrum (400–500 nm). A challenge to the use of chemiluminescence to monitor biological processes is the presence of interfering substances in the biological optical window. In the present study, longer wavelength emitting fluorophores (the organic dyes Alexa 568 and Alexa 647), and a semiconductor nanoparticle (QDOT800) were used to red‐shift the emission from commercially available 1,2‐dioxetane‐based chemiluminescent substrate reactions. By adding non‐conjugated fluorescent emitters into chemiluminescent reaction mixtures, an emission peak occurred at the predicted wavelength of the fluorescent emitter. The excitation and emission from QDOT800 was preserved in the presence of a 100 µm‐thick glass barrier separating it from the chemiluminescent reaction components. The maximum tissue phantom penetration by QDOT800 emission was 8.5 mm; in comparison, the native chemiluminescent emission at 500 nm was unable to penetrate the thinnest tissue phantom of 2.5 mm. The described method for red‐shifted emissions from chemiluminescent reactions does not require direct interaction between the chemiluminescent reaction and the fluorescent emitters. This suggests that the mechanism of chemiluminescent excitation of fluorophores and QDOT800 is not exclusive to chemiluminescence resonance energy transfer or sensitized chemiluminescence, but rather by broad energization from the native chemiluminescent emission. Copyright © 2014 John Wiley & Sons, Ltd.     

Visible‐near‐infrared luminescent lanthanide ternary complexes based on beta‐diketonate using visible‐light excitation

We used the synthesized dinaphthylmethane (Hdnm) ligand whose absorption extends to the visible‐light wavelength, to prepare a family of ternary lanthanide complexes, named as [Ln(dnm)₃phen] (Ln = Sm, Nd, Yb, Er, Tm, Pr). The properties of these complexes were investigated by Fourier transform infrared (FT‐IR) spectroscopy, diffuse reflectance (DR) spectroscopy, thermogravimetric analyses, and excitation and emission spectroscopy. Generally, excitation with visible light is much more advantageous than UV excitation. Importantly, upon excitation with visible light (401–460 nm), the complexes show characteristic visible (Sm³⁺) as well as near‐infrared (Sm³⁺, Nd³⁺, Yb³⁺, Er³⁺, Tm³⁺, Pr³⁺) luminescence of the corresponding lanthanide ions, attributed to the energy transfer from the ligands to the lanthanide ions, an antenna effect. Now, using these near‐infrared luminescent lanthanide complexes, the luminescent spectral region from 800 to 1650 nm, can be covered completely, which is of particular interest for biomedical imaging applications, laser systems, and optical amplification applications. Copyright © 2015 John Wiley & Sons, Ltd.     

Photo‐Rechargeable Electric Energy Storage Systems

The global energy demand is increasing at the same time as fossil fuel resources are dwindling. Consequently, the search for alternative energy sources is a major topic worldwide. Solar energy is one of the most promising, effective and emission‐free energy sources. However, the energy has to be stored to compensate the fluctuating availability of the sun and the actual energy demand. Photo‐rechargeable electric energy storage systems may solve this problem by immediately storing the generated electricity. Different combinations of solar cells and storage devices are possible. High efficiencies can be achieved by the combination of dye‐sensitized solar cells (DSSC) and capacitors. However, other hybrid devices including DSSCs or organic photovoltaic systems and redox flow batteries, lithium ion batteries and metal air batteries are playing an increasing role in this research field. This Progress Report reviews the state of the art research of photo‐rechargeable batteries based on organic solar cells, as well as storage modules.     

Biomass production and energy balance of a 12‐year‐old short‐rotation coppice poplar stand under different cutting cycles

Given today's political targets, energy production from agricultural areas is likely to increase and therefore needs to be more sustainable. The aim of this study was thus to carry out a long‐term field trial based on the poplar short‐rotation coppice (SRC), in order to compare dry matter, energy‐use efficiency and the net energy yield obtainable from this crop in relation to different harvest frequencies (1‐, 2‐ and 3‐year cutting cycles). The results showed that poplar SRC performed very well under temperate climates as it can survive up to 12 years, providing a considerable annual biomass yield (9.9, 13.8, 16.4 t ha^?1 yr^?1 for annual T1, biannual T2 and triennial T3 cutting cycles, respectively). The system tested in southern Europe showed a positive energy balance characterized by a high energy efficiency. We found that the choice of harvest interval had huge consequences in terms of energy yields. In fact, the energy efficiency improved from T1 to T2 and T3, while the net energy yield increased from 172 to 299 GJ ha^?1 yr^?1. This study suggests that, with 3‐year harvest cycles, poplar SRC can contribute to agronomic and environmental sustainability not only in terms of its high yield and energy efficiency but also in terms of its positive influence on limiting soil tillage and on the environment, given its low pesticide and nutrient requirements.