Energy advances最新文献

Unraveling the knowledge of the complex refractive index and photophysical properties of the perovskite layer is paramount to uncovering the physical process that occurs in a perovskite solar cell under illumination. Herein, we probed the optical and photophysical properties of FAPbI₃ (FAPI) and Cs_0.1FA_0.9PbI₃ (CsFAPI) thin films deposited from pre-synthesized powder, by the spectroscopic ellipsometer and time-resolved fluorescence spectra. We determined the complex refractive index of perovskite films by fitting the measured spectroscopic ellipsometer data with the three-oscillator Tauc-Lorentz (T-L) model. We deduced that the CsFAPI thin film had a slightly lower absorption coefficient than the FAPI, but a higher refractive index and dielectric constant than the FAPI. The peak photoluminescence (PL) emission of FAPI and CsFAPI thin film on glass substrates was observed around 803 nm and 799 nm, respectively, while on ITO substrates, both FAPI and CsFAPI thin film was quenched and red-shifted to 816 nm. The methylammonium free pure CsFAPI-based perovskite solar cell fabricated in p-i-n configuration, measured a competitive efficiency of 16.14%, characterized by a J _SC of 23.995 mA cm^-2, V _OC of 912 mV, and FF of 73.74%.

In this report, we demonstrate a strategy to selectively suppress reactions at unpassivated active material surfaces in silicon composite electrodes, mitigating the capacity-draining effects of continual electrolyte reduction in alloying-type anodes for lithium-ion batteries. Inspired by dipolar modification of electrodes for photovoltaic applications, we introduced conformationally-labile permanent dipoles at the electrochemical electrode interface to dynamically modulate charge transfer kinetics across the interface. Polyacrylic acid (PAA) binder modified with the dipole-bearing molecule 3-cyanopropyltriethoxysilane displays a 17% increase in capacity retention versus unmodified PAA binder. Differential capacity analysis shows a marked cathodic shift of ∼150 mV in overpotential in the pre-alloying voltage range following the initial solid electrolyte interphase (SEI) formation step. At the same time, we observe negligible shift in overpotential for reversible lithium-ion storage, consistent with selective modulation of irreversible reaction kinetics. Electrochemical impedance spectroscopy indicates that this modification results in a thinner SEI layer. Despite the improved performance, the charge transfer resistance of the half-cell is higher with the modification, suggesting some opportunity for improving the strategy. Time-resolved spectroelectrochemical analysis of desolvation kinetics in modified binders indicates that the modified binder has slower and less selective ion transport. We conclude that future iterations of this strategy which avoid disrupting the beneficial ionic transport properties of the binder would result in even greater performance enhancement. We propose that this may be accomplished by incorporating oligomeric dipolar modifiers, either in the binder or at the active material itself. Either way would increase the ratio of dipoles to PAA linking sites, thus avoiding the competing deleterious impacts on device performance.

This study presents a comprehensive cradle-to-gate life cycle assessment (LCA) of synthetic methanol production, integrating low-temperature solid sorbent direct air capture (DAC) systems with renewable energy sources and green hydrogen to evaluate the environmental impacts of various renewable energy configurations for powering the DAC-to-methanol synthesis processes. Renewable energy-powered configurations result in significantly lower greenhouse gas (GHG) emissions than traditional methanol production methods and DAC systems powered by conventional grid energy. Energy configurations analyzed are current US grid mix, solar photovoltaic (PV) in Alabama and Arizona, USA, onshore wind, run-of-river hydroelectric, and geothermal. Notably, hydroelectric and wind power in the western United States emerge as the most sustainable options, showing the lowest global warming potential (GWP) impacts at −2.53 and −2.39 kg CO₂ eq. per kg methanol produced, respectively, in contrast to the +0.944 kg CO₂ eq. from traditional steam methane reforming. Furthermore, this research investigates the use of various heat sources for regenerating low-temperature solid sorbent DAC, emphasizing the potential integration of new experimental results of novel microwave-based regeneration compared to industrial waste heat. Through the analysis of renewable energy scenarios and DAC regeneration heat sources, the research emphasizes the pivotal role of sustainable energy sources in climate change mitigation. This study introduces a new approach by comparing both various renewable energy sources and DAC heat sources to identify the most optimal configurations. This work is also distinguished by its integration of new experimental data on microwave DAC regeneration, offering a unique contribution to the existing body of knowledge. This LCA scrutinizes the environmental impacts of renewably powered DAC-to-methanol systems and compares them with traditional methanol production methods, revealing the significant potential for carbon neutrality. The findings highlight the importance of strategic technology and energy source optimization to minimize environmental impacts, thus guiding the scaling up of DAC and renewable energy technologies for effective climate mitigation. By recognizing the environmental advantages of integrating renewable energy sources with DAC-to-methanol technologies, this research marks a significant step forward in advancing DAC technology and pushes the boundaries of green methanol production toward true sustainability.

Common ultraviolet (UV) photodiodes or detectors for measuring the intensity of UV-light-emitting diodes (LEDs) in UV disinfection systems are costly. This study explores the potential of using low-cost UV-LEDs as photometers for monitoring UV intensity in water systems. Reverse LEDs (rLEDs) generate a small current proportional to the incident light intensity on the p–n junction when operated in unbiased mode. rLEDs with different wavelengths and power levels were examined to find the optimal rLED for monitoring the intensity of a 275 nm LED strip, achieving less than 1% deviation from a calibrated spectroradiometer. The influence of temperature was also examined on rLED measurements and found non-negligible. This work demonstrates the feasibility of using rLEDs as intensity monitoring sensors for UV-C LED sources, offering a low-cost and reliable alternative for UV intensity monitoring in UV-LED water disinfection systems.

This work demonstrates the first experimental evidence of the acid–base concentration swing (ABCS) for direct air capture of CO₂. This process is based on the effect that concentrating particular acid–base chemical reactants will strongly acidify solution, through Le Chatelier's principle, and result in outgassing absorbed CO₂. After collecting the outgassed CO₂, diluting the solution will result in a reversal of the acid–base reaction, basifying the solution and allowing for atmospheric CO₂ absorption. The experimental study examines a system that includes sodium cation as the alkalinity carrier, boric acid, and a polyol complexing agent that reversibly reacts with boric acid to strongly acidify solution upon concentration. Though the tested experimental system faces absorption rate and water capacity limitations, the ABCS process described here provides a basis for further process optimization. A generalized theoretical ABCS reaction framework is developed and different reaction orders and conditions are studied mathematically. Higher order reactions yield favorable cycle output results, reaching volumetric cycle capacity above 50 mM for third-order and 80 mM for fourth-order reactions. Optimal equilibrium constants are determined in order to guide alternative chemical searches and synthetic chemistry design targets. There is a substantial energetic benefit for reaction orders above the first, with second- and third-order ABCS cycles exhibiting a thermodynamic minimum work for the concentrating and outgassing steps around 150 kJ per mole of CO₂. A significant advantage of the ABCS is that it can be driven through well-developed and widely-deployed desalination technologies, such as reverse osmosis, with opportunities for energy recovery when recombining the concentrated and diluted streams, and extraction can occur directly from the liquid phase upon vacuum application.

This study explores the microreactor-assisted soft lithography (MASL) method for direct, one-step synthesis and patterning of additive-free antimony sulfide (Sb₂S₃) nanostructured thin films. The results reveal the steady state process and its ability to overcome the challenges and limitations of conventional solution deposition processes. This new approach, exploiting continuous flow, prevents the dissolution of the growing film, a common issue in batch solution deposition methods. Furthermore, this study successfully fabricates functional Sb₂S₃–Li coin cell prototypes, demonstrating stable specific capacities of 600 mA h g⁻¹ for over 260 cycles at a C/2 charge rate and coulombic efficiencies of 96–98%.