Energy advances最新文献

Correction for ‘Steady states and kinetic modelling of the acid-catalysed ethanolysis of glucose, cellulose, and corn cob to ethyl levulinate’ by Conall McNamara et al., Energy Adv., 2024, 3, 1439–1458, https://doi.org/10.1039/D4YA00043A.

The quest for sustainable energy storage has spotlighted zinc-ion batteries (ZIBs) for their safety, cost-effectiveness, and eco-friendliness. Manganese oxides, particularly Mn₃O₄, stand out as promising cathode materials due to their electrochemical virtues and affordability. However, traditional synthesis methods like solid-state reactions, hydrothermal processes, and sol–gel techniques often entail complex procedures, high temperatures, and environmentally harmful chemicals, which impede their practical applications. This study introduces a novel, eco-friendly synthesis route for Mn₃O₄ nanoparticles via the room-temperature reaction of morpholine with manganese nitrate for 24 h, reducing both the environmental impact and the complexity of production. This method yields Mn₃O₄ nanoparticles with enhanced crystallinity and surface area, which is crucial for improved electrochemical performance in ZIBs by offering increased active sites for zinc intercalation. The resultant high-performance Mn₃O₄ nanoparticles align with sustainable practices and hold the potential for advancing next-generation energy storage technologies. The detailed structure and electrochemical performance were investigated in detail in this study. The produced Zn//Mn₃O₄ nanoparticles cell exhibited a remarkable electrochemical performance, which displayed a high reversible capacity of 209.7 mAh g⁻¹ after 300 cycles at 0.6 A g⁻¹.

Glycerol (GLY) is an attractive biobased platform chemical that produces valuable fine chemicals with a wide range of industrial applicability and has the potential to produce high-purity H₂ gas. Herein, we established an efficient method for selective production of H₂ gas and lactic acid (LA) from aqueous glycerol under mild reaction conditions (90–130 °C) over various supported ruthenium catalysts. Notably, we achieved a substantial yield of H₂ gas (n(H₂)/n(GLY) ratio of 1.4 with >99.9% H₂ purity) and LA (86%) from glycerol over Ru nanoparticles immobilized over a La(OH)₃ support (Ru/La(OH)₃) in contrast to bare Ru nanoparticles where we observed a n(H₂)/n(GLY) ratio of 1.6 with only 70% yield of LA as we reported previously. We could significantly boost the generation of both H₂ gas and LA by tuning the reaction parameters, including reaction time, temperature, base, and water concentrations. Furthermore, the effect of various support materials such as Mg(OH)₂, ZnO, ZrO₂, and TiO₂ was also tested for H₂ production from GLY under optimized reaction conditions. The employment of various characterization techniques to understand the physicochemical properties of the synthesized supported Ru catalysts revealed that the choice of support material significantly influenced the catalytic activity towards the selective production of H₂ and LA.

In Li–ion batteries with conventional liquid electrolytes, the formation of solid electrolyte interphases (SEIs) at carbonaceous anodes prevents continuous electrochemical decomposition of the electrolyte. Typically, SEI formation and electrolyte decomposition are examined with linear potential scans, where time and potential dependencies are intertwined. Herein, a stepwise potential variation in combination with amperometry and electrochemical impedance spectroscopy (EIS) is used to characterize the impacts of time and potential as individual degrees of freedom on the SEI formation. Based on EIS data, the double layer capacitance (DLC) is introduced as a sensitive in situ metric to monitor the SEI formation. This technique is used to show the similarities and differences in the SEI formation processes with typical Li–ion battery electrolytes consisting of hexafluorophosphate and carbonate solvents. A polished glassy carbon electrode is employed to provide model-like EIS data with reliable interpretation. Changes in the electrochemical interface within only few atomic layers are tracked with DLC, indicating that SEIs are formed below 1.9 V vs. Li/Li⁺ with the employed electrolytes. Amperometry measurements show that the decomposition of the employed electrolytes starts at approximately 2.7 V vs. Li/Li⁺, displaying smaller electrochemical windows than those previously reported.

We present processed light emitting diodes (LED) devices based on GaInP core-branch nanowire (NW) structures. The LEDs rely on the charge carrier diffusion induced light emitting diode concept. The GaInP core has a higher Ga content than the branches to induce diffusion of carriers from the cores into the branches. The branches play the role of the active region in the structure, where charge carriers recombine to emit light. We investigate the impact of n-doping the branches on the performance of the LEDs. Electroluminescence measurements provide insights on the emission spectrum with varying dopant molar fraction. External quantum efficiency (EQE) measurements provide insights into the device quality, and reveal the limitations encountered in processing, such as the high sheet resistance of the indium tin oxide (ITO) transparent conductive top contact. Temperature dependent measurements allow us to probe the effect of contact resistance by measuring the I–V curve as a function of temperature. The work identifies performance limitations and paths to overcome them.

Single atom platinum catalysts, characterized by isolated Pt atoms dispersed on suitable supports, exhibit high hydrogen evolution catalytic mass activity. The activity is usually limited by the low density of Pt atoms on the substrate. Herein, we report on a single step synthesis of a catalyst from organometallic precursors of Ni and Pt which yields a high density of Pt atoms on Ni nanoparticles dispersed on a carbon support. The spontaneous formation of Pt single atoms on the surface of Ni has not been reported in a single step reaction and is a unique feature of the organometallic route. This route allowed us to increase the atomic ratio of single Pt atoms to Ni up to 10% compared to 2% reported previously. Single Pt atoms on Ni catalysts display a high hydrogen evolution reaction activity of 660 mA mg_Pt⁻¹ (8 times more than that of commercial Pt) and stability as HER catalysts compared with commercial Pt/C catalysts.

Interest in sustainable and bio-inspired materials for optoelectronic applications is burgeoning, driven by the prospect of greener production, compatibility with large-scale manufacturing and potential biocompatibility. This study introduces two analogues of the biological redox co-factor flavin (BFG, BFA) as bioinspired electron-transporting materials featuring solubilizing ethylene glycol and alkyl side chains. These materials demonstrated a conductivity of ∼5.6 × 10⁻⁷ S cm⁻¹ in their pristine form which compares favourably with widely employed PCBM (6.8 × 10⁻⁸ S cm⁻¹). To enhance the conductivity of the material the chemical dopant N-DMBI was added. UV-vis absorption and electron spin resonance measurements confirmed radical anion formation, while glycol-functionalized derivative BFG shows faster reactivity toward the dopant due to increased polarity of the acceptor molecule conferred by the more polar side chain. Surprisingly, these materials did not exhibit the expected enhancement effect in terms of conductivity or increased power conversion efficiency in perovskite solar cells. DFT calculations correlated to features in the absorption spectra of the compounds indicates the formation of stable charge-transfer complexes upon the addition of the dopant. We hypothesise that this inhibits electron transfer of the reduced species in the film to its undoped neighbour and thereby prevents effective doping. Our results highlight the significance of charge-transfer complexation in the design of future electron transporting materials for perovskite solar cells and advocates the use of low cost DFT modelling early on in the design of these species and their dopants.

Harnessing waste green energy utilizing advanced energy conversion technologies is widely considered a promising avenue for enhancing the power generation capacity of renewable energy. In this study, we present the experimental realization of a tailored energy conversion device using graphene-carbon black/polyvinyl chloride (G-CB/PVC) composite films for the innovative harvesting of rainwater energy. Based on the cyclic charge–discharge behaviors of electron/cationic pseudocapacitance at the film–raindrop interface, periodic current and voltage signals were generated with maximum values exceeding 2.5 μA and 100 μV per droplet by optimizing the concentrations and species of cations, respectively. Electricity outputs were significantly enhanced by increasing the electron concentration in the composite films. It is noteworthy that rainwater energy-harvesting devices exhibit exceptional long-term stability, enduring persistent attacks posed by continuous simulated rainfall conditions.

The decoupling nature of energy and power of redox flow batteries makes them an efficient energy storage solution for sustainable off-grid applications. Recently, aqueous zinc–iron redox flow batteries have received great interest due to their eco-friendliness, cost-effectiveness, non-toxicity, and abundance. However, the development of zinc–iron redox flow batteries (RFBs) remains challenging due to severe inherent difficulties such as zinc dendrites, iron(III) hydrolysis, ion-crossover, hydrogen evolution reactions (HER), and expensive membranes which hinder commercialization. Many scientific initiatives have been commenced in the past few years to address these primary difficulties, paving the way for high-performance zinc–iron (Zn–Fe) RFBs. This review collectively presents the various aspects of the Zn–Fe RFB including the basic electrochemical cell chemistry of the anolyte and catholyte, and the different approaches considered for electrodes, electrolytes, membranes, and other cell components to overcome the above issues. This review summarizes the recent activities and viewpoints for obtaining high-performance Zn-Fe RFBs.

Although lead based MAPbI₃ has been used as a material for photocatalytic hydrogen evolution, conventionally synthesized MAPbI₃ in HI solution suffers from very low HER activity with a hydrogen evolution rate of 30 μmol h⁻¹ g⁻¹. Several efforts have been made to boost the HER performance by tagging a co-catalyst. But no such significant approach was developed to improve the HER activity of pristine MAPbI₃. In this work, the shape and morphology of MAPbI₃ have been modified by a simple solvent change route. This led to substantial transformation in shape and morphology affecting various facets of photocatalytic and photoelectrochemical performance. DMF assisted pristine MAPbI₃ exhibited an HER activity of 830 μmol h⁻¹ g⁻¹, almost 28-fold better than that of typical HI based MAPbI₃. This work highlights how solvent transition from HI to DMF can influence the shape and surface morphologies which impact the photocatalytic and photoelectrochemical performances of pristine MAPbI₃. To further enhance the HER activity of DMF assisted MAPbI₃, the as-synthesized polyfluorene co-catalyst was integrated on the MAPbI₃ surface. Under optimized conditions, the hydrogen evolution of MAPbI₃/polyfluorene composites can reach up to 6200 μmol h⁻¹ g⁻¹.