Energy advances最新文献

The effects of a remote oxygen plasma (ROP) treatment on the surface of commercial graphite felts were investigated and compared against a conventional thermal treatment. In contrast to methodologies where the sample is directly exposed to the plasma, ROP allows for a high control of sample–plasma interaction, thereby avoiding extensive etching processes on the fibre surface. To assess the impact of ROP treatment time, the electrodes were subjected to three different periods (10, 60, and 600 seconds). X-ray photoelectron spectroscopy showed that the ROP treatment introduced nearly three times more surface oxygen functionalities than the thermal treatment. Raman spectroscopy measurements revealed a significant increase in amorphous carbon domains for the ROP samples. The thermal treatment favoured increases in graphitic defects and resulted in an order of magnitude larger ECSA compared to the ROP treated materials despite having lower content in oxygen functionalities. The electrochemical analysis showed enhanced charge-transfer overpotentials for GF400. The ROP samples exhibited a lower mass-transport overpotential than the thermally treated material and had similar permeabilities, which overall translated to the thermal treatment offering better performance at fast flow rates. However, at slow flow rates (∼10 mL min⁻¹), the ROP treatment for the shortest period offered comparable performance to conventional thermal treatment.

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.

For the first time, a cost-effective glass fiber (GF) support derived from waste printed circuit boards (W-PCBs) was utilized to synthesize a reusable GF-supported gallium–molybdenum photocatalyst (GaMo–GF) for generating fermentable sugar (FS) from delignified corncob (DCC) in a quartz halogen solar batch reactor (QHSR). Additionally, this paper presents a comparative detoxification investigation and subsequent fermentation of the resulting FS using Pichia stipitis. The optimum Ga⁴Mo-GF (with a gallium precursor loading of 4 wt%) photocatalyst exhibited impressive characteristics, including a high specific surface area (28.01 m² g⁻¹), high pore volume (0.04198 cc g⁻¹) and lower band gap energy (2.3 eV), providing a maximum 78.35 mol% FS yield under mild reaction conditions (100 °C and 20 min) with mild energy consumption (12 kJ mL⁻¹). The comparative hydrolysate detoxification study highlighted the superior efficacy of the Amberlite IRP69 cation resin, achieving maximum removal rates of 86% for furfural, 92% for formic acid, and 95% for levulinic acid compared to other methods. Furthermore, the hydrolysate detoxified using Amberlite IRP69 resulted in a higher bioethanol concentration (4.32 mmol mL⁻¹) compared to NaOH neutralization (3.06 mmol mL⁻¹), Ca(OH)₂ over-liming (2.88 mmol mL⁻¹), and ethyl acetate solvent extraction (3.73 mmol mL⁻¹) when fermented with Pichia stipitis. Additionally, the overall environmental impact assessment indicated that utilizing the Amberlite IRP69 cation resin not only enhanced bioethanol yield but also reduced environmental impacts. Remarkably, the optimized Ga⁴Mo-GF catalyst demonstrated reusability for up to 7 cycles in the DCC hydrolysis process, showcasing its stability and the consequential reduction in environmental impacts throughout the corncob to bioethanol conversion process.

The degradation of woody biomass in methanol/water mixtures at elevated temperatures and pressures is a promising candidate for chemical production from renewable resources, combining the wood-degrading ability of water with the product-dissolving capacity of methanol. However, the effects of water and methanol on wood degradation remain unclear. In the present study, the effect of process parameters on the degradation of Japanese cedar in methanol/water at 270 °C and 10–30 MPa was investigated using a semi-flow reactor in which pressure and temperature can be controlled independently. At 270 °C, hemicelluloses were degraded and solubilized more preferentially at 10 MPa, but delignification was more preferred at 20 and 30 MPa. In the resulting products, methylation of coniferyl alcohol from lignin and methyl esterification of methyl glucuronopentosan from hemicellulose were more advanced at 20 and 30 MPa than at 10 MPa. These results suggest that at 10 MPa the influence of water is dominant and promotes polysaccharide degradation, whereas at 20 and 30 MPa the influence of methanol is dominant and promotes delignification. Our findings will provide insight into the establishment of efficient chemical production from woody biomass with solvolysis technology.

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%.

Two-dimensional (2D) layered halide perovskites are considered to be one of the future potential semiconductor materials due to their higher moisture stability than three-dimensional (3D) perovskites. However, improving their optical and electrical properties is still necessary for critical applications. The technique of additive engineering can be utilized to tune and enhance the optoelectrical properties of the 2D perovskites. This work studies the impact of mixing a certain amount of a fullerene derivative ‘[6,6]-phenyl C₆₁-butyric acid methyl ester’ (PCBM) into 2D (PEA)₂PbI₄ perovskite thin films (PEA = phenyl ethyl ammonium). The studies show that PCBM does not affect the structure and bandgap of the (PEA)₂PbI₄ perovskite. On the other hand, PCBM improves photoluminescence emission intensity and promotes charge separation at the perovskite/PCBM interface. Further studies convey that, even though PCBM can heal certain defect states in the (PEA)₂PbI₄ perovskite material, the electrons generated under intense illumination at the perovskite/PCBM interface are trapped by this fullerene derivative. Hence, PCBM plays a dual role when mixed with the (PEA)₂PbI₄ perovskite, as (1) a defect healing agent and (2) an electron acceptor. However, over continuous illumination on the (PEA)₂PbI₄ perovskite thin films, the photoexcited electrons are trapped by PCBM. As a result, the photocurrent response and the photocatalytic reaction rate get reduced in PCBM mixed (PEA)₂PbI₄ perovskite thin films.

The immense demand for electrical energy motivated us to manipulate solar energy by means of conversion through solar cells (SCs). Advancements in photovoltaic (PV) technology are occurring very rapidly. In recent years, extensive research has been conducted on halide perovskite-based SCs because of their superior optoelectronic properties, enhanced efficiency, lightweight nature, and low cost. However, concerns have arisen regarding their longevity, stability, and commerciality due to the presence of toxic lead (Pb). The most prominent purpose of this investigation is to discover additional efficient, sustainable, and eco-friendly device architectures. In this study, we investigated an all-inorganic, lead-free rubidium germanium iodide (RbGeI₃)-based PSC device with the assistance of the SCAPS-1D simulator. Several electron transport layers (ETLs) and hole transport layers (HTLs) were incorporated with the perovskite layer, and an efficient primary structure was discovered. Then, the impact of temperature; back metal work function; series and shunt resistance; surface recombination velocity of carriers; thickness of the perovskite absorber layer, electron transport material (ETM), and hole transport material (HTM); carrier concentration of the perovskite absorber layer, ETM, and HTM; defect density of the perovskite absorber layer, ETM, and HTM; and defect density of the HTL/absorber and absorber/ETL interfaces on the PV performance of the proposed PSC device was analyzed. The optimized device exhibited a power conversion efficiency (PCE) of 30.35%, with superior values for open circuit voltage (V_oc), short circuit current density (J_sc), and fill factor (FF) of 1.067 V, 33.15 mA cm⁻², and 85.82%, respectively. The investigations in this study may be valuable and impactful to solar cell material researchers and move the research interest forward by one step so that experimental work with non-toxic RbGeI₃-based PSC devices will be performed in the future.