Sustainable Energy & Fuels最新文献

Environmental impacts from the fashion industry are at the top of global pollution. Fiber production, fabric preparation and distribution, and disposal of textiles combined with the excessive consumerism of clothing result in the wastage of thousands of million cubic meters of fresh water, the release of gigatons of CO₂ equivalent, and tens of millions of metric tons of textile waste generation every year. This situation shows that there is an urgent and mandatory need to change the fashion paradigm, but, even if accomplished, the current textile waste spread worldwide still needs to be managed in an environmentally conscious way. Upcycling textile waste by pyrolysis is gaining interest as an alternative management option. The goal is to endow waste with new functionalities for its repurposing into new applications. This study focuses on applying pyrolysis to convert discarded clothing into a conductive carbon textile while avoiding treatments with hazardous chemicals. Envisioned to be applied for current collection in all-organic primary power sources, the ultimate goal is to replace synthetic polymers in commercial carbon current collectors. Actual textile waste has been successfully pyrolyzed without the need for pre-treatments or activation. The structural composition of the samples was studied by SEM, X-ray diffraction, Raman spectroscopy, ATR-FTIR spectroscopy, EDS and BET surface area. Electrical and electrochemical characterization showed their suitability as current collectors, which was demonstrated by building an aqueous metal-free organic primary battery. A system of innocuous quinone-based redox chemistry coupled with the revalorized collectors delivered 11.17 mA cm⁻² and 1.4 mW cm⁻² of power density, proving the feasibility of the proposed application.

There is a renascence in the use of triphenylamine (TPA)-based donor materials in the field of perovskite photovoltaics. This work presents the synthesis of two novel conjugated small molecules (CSMs), TPA-t and TPA-t EH, which are functionalized with triisopropylsilyl groups and 2-ethylhexyl side chains. These molecules show promise as hole transport materials, which possess high hole mobilities of 1.5 × 10⁻⁴ and 2.9 × 10⁻³ cm² V⁻¹ s⁻¹. TPA-t and TPA-t EH possess HOMO energy levels at −5.38 and −5.31 eV, which are well-aligned with the valence band of standard perovskite MAPbI₃. This resulted in outstanding open-circuit voltages of 1100 and 1080 mV. TPA-based molecules were investigated as HTLs in n-i-p PSCs without additional doping and enabled high efficiency (17.3%) same as for devices with the state-of-the-art polytriarylamine (PTAA) HTL. The obtained results suggest that the developed materials could potentially compete with PTAA with further material structure modification.

Hydrothermal pretreatment is a promising approach to lignocellulosic biomass processing for enzymatic hydrolysis and high-yield bioethanol fermentation, as it reduces downstream inhibitor content and the amount of toxic byproducts generated. In this study, the ethanol yield and productivity of an engineered xylose-fermenting strain of Saccharomyces cerevisiae were tested on lignocellulosic hydrolysates produced with varying citrate buffer concentration, solid loading, supplemental nitrogen source, and feedstock of origin, and a semi-integrated bioprocess which integrates enzymatic hydrolysis and bioethanol fermentation was developed. The greatest ethanol yields (g_p/g_s) of 0.490 ± 0.008, 0.460 ± 0.001, 0.420 ± 0.002 and 0.410 ± 0.002 were obtained from bioenergy sorghum (BES), Miscanthus × giganteus (MG), energy cane (EC), and oilcane (OC), respectively. In addition, an equivalent of 291 L, 253.54 L, 257.8 L, and 260.3 L of bioethanol were produced per ton of BES, MG, EC, and OC, respectively, by using urea as a nitrogen source in a bioreactor.

Sb₂Se₃ is a promising photocathode with good stability and large theoretical photocurrent density but suffers from severe recombination of electron–hole pairs at the interface, which greatly limits its application in photoelectrochemistry. To tackle this issue, heterostructured photoelectrodes with efficient cocatalysts should be rationally designed and fabricated, which are usually made by expensive and complicated atomic layer deposition methods (ALD). Herein, a facile chemical bath deposition (CBD) method is proposed to construct heterostructured photocathodes composed of TiO₂ and Sb₂Se₃, as well as to deposit a cocatalyst of Pt nanoparticles (NPs) on the photoelectrode. The TiO₂ layer could protect Sb₂Se₃ and also capture the photogenerated electrons produced by Sb₂Se₃, and then improve charge separation. Pt is utilized as a co-catalyst to enhance the carrier injection efficiency and hence accelerate the surface hydrogen evolution reaction. Under simulated sunlight conditions, Sb₂Se₃-5/TiO₂-3/Pt-6 with the optimized configuration exhibited a flat band potential of 0.52 V_RHE, which is positively shifted by 0.09 V with respect to that of bare Sb₂Se₃. Notably, photocurrent densities of −1.0 mA cm⁻² at −0.2 V_RHE and 0.56 mA cm⁻² at 0 V_RHE were achieved. This represented 12.5 and 7 times improvement in photocurrent densities compared to bare Sb₂Se₃ NPs. Our study provides a facile and effective method for the interface engineering of Sb₂Se₃, resulting in a significant enhancement of its photoelectrochemical activity for serving as a high-performance photocathode for solar water splitting.

Interfacial solar steam generation (ISSG) is an effective method to produce clean water through evaporating seawater actuated by solar energy. Nevertheless, developing a solar evaporator that is simultaneously simple in process and maintains good stability and high efficiency is still difficult but in great demand. Herein, an aerogel solar evaporator was prepared by cross-linking chitosan (CS) and two-dimensional transition metal carbide/nitride (MXene) nanosheets with excellent properties via a simple freeze-drying strategy. The unique three-dimensional network structure and good biocompatibility could facilitate quick transport of water from the bottom up to the evaporation surface by capillary force. MXene nanosheets combined a broad spectral response with strong solar absorption capacity, enabling the CS/MXene aerogel solar evaporator to exhibit strong light absorption, light-to-heat conversion, and water transport capabilities. The results showed that the water evaporation rate under one sun was as high as 1.80 kg m⁻² h⁻¹, with an energy conversion efficiency of 75.2%. Notably, the stability of the solar evaporator ensured stable solar water evaporation over a long period compared with most CS-based solar evaporators. Meanwhile, clean water could be continuously produced from acidic, alkaline and organic dye solutions, and saline brines. These tactics pave a new way for developing solar absorbers for solar-driven desalination.

Rational design of materials in a catalytic system is the main determinant of the efficiency of sustainable energy sources. Significant efforts have focused on the study and development of flatland two-dimensional (2D) materials (MXenes, MBenes, transition metal dichalcogenides/phosphides (TMDs/TMPs), phosphorene, graphene derivatives) towards energy-driven aspirations in consideration of their superior physiochemical properties as compared to their non-layered counterpart materials, surpassing their transport properties and conductivity. Herein, we aim to provide a detailed account of where the flatland materials currently stand to achieve the goal of sustainability in light of their photochemical and electrochemical nitrogen fixation applications. As of now, numerous challenges have limited the expansion of 2D-material derived nitrogen fixation operations for scalable applications. Therefore, we summarized techno-economic analysis and future perspectives of nitrogen fixation applications in relation to their practical ammonia applicability. We have briefly summarized the functionality of flatland materials and classified them on the basis of their photochemical and electrochemical efficiencies.

The augmentation of photocatalytic activity in layered perovskite oxides via the integration of graphene-like materials presents a promising pathway for the optimization of solar energy conversion. The electron-rich nature of graphene, coupled with its high electron conductivity, functions as an effective photosensitizer, thereby enhancing visible light harvesting. In this investigation, we have, for the first time, assembled ultrathin exfoliated Dion–Jacobson perovskite layers with reduced graphene oxide (rGO) layers, resulting in a high surface area layered nanocomposite, achieved through a tailored electrostatic approach. To further refine the electron properties of the layered perovskite–reduced graphene oxide composites, we have explored the use of various lanthanides as A-site cations in the Dion–Jacobson perovskites, including LaNb₂O₇ (LNO), PrNb₂O₇ (PNO), and NdNb₂O₇ (NNO). The synthesized composites demonstrate exceptional performance in photocatalytic H₂ production, with rGO/NNO exhibiting the highest activity, achieving a hydrogen evolution rate (HER) of 835 μmol g⁻¹ under light illumination, attributable to optimal interfacial effects. Our experimental and theoretical analyses indicate that hydrogen production is predominantly influenced by the A-site cation charge density at the materials' interface, as dictated by the charge transfer dynamics. This research potentially contributes to the comprehension and enhancement of photocatalytic processes for applications in solar energy conversion.

Valorization of lignocellulosic biomass, an abundantly available renewable hydrocarbon source, to produce value-added chemicals, drop-in chemicals, and biofuels is indispensable, considering the limited sources of fossil fuels and their adverse environmental effects. The application of efficient heterogeneous catalysts is a promising method of sustainable biomass processing with low energy consumption and minimal waste generation. Hydroprocessing of biomass using a hydrogen source is considered to be a pivotal strategy for the synthesis of industrially important chemicals and fuels. As the use of molecular hydrogen gas results in several problems and requires harsh reaction conditions, the utilization of safe and clean liquid hydrogen carriers is preferred to address the economic and sustainable aspects of biorefinery. In this review, we address the significance of in situ hydrogen generation for biomass hydroprocessing. The primary focus of the review is the catalytic transfer hydrogenation (CTH) of lignocellulosic biomass-derived molecules using various liquid hydrogen carriers. Various heterogeneous catalysts, including bulk, nanosized, and single-atom catalysts, and the role of their BET surface area, pore size, particle size/morphology, surface chemistry, acid–base, and redox properties in biomass hydrogenation to obtain desirable products are meticulously discussed with the support of kinetic, mechanistic, and theoretical studies. The challenges associated with the in situ generation of hydrogen and its selective adsorption/activation on the catalyst surface for the CTH processing of biomass-derived molecules as well as the prospects for a rational design of novel heterogeneous catalysts and the utilization of new hydrogen carriers for biomass valorization are elucidated.

This study investigates the impact of diesel pilot ignition (DPI) natural gas (NG) engines on combustion and emission characteristics across various exhaust gas recirculation (EGR) volumes. It utilizes a three-dimensional computational fluid dynamics (CFD) model coupled with a simplified chemical kinetic model. Experimental results guide simulation calculations under three distinct operational conditions. Visual analysis of the calculation outcomes presents the combustion process and emission characteristics in the engine, elucidating the influence mechanism in relation to EGR volume rates. The simulation results show that, with the rise of EGR rates, the peak in-cylinder pressure decreases by 15 bar, the heat release rate (HRR) shoots up later, and the maximum difference of CA50 is less than 2.7 °CA. The variation trends of CA90, 50–90% and 10–90% combustion durations exhibit similarity. When the rate of EGR volume is below 20%, the CA90, 50–90%, and 10–90% combustion durations lengthen as the rate of EGR volume increases. When the rate of EGR volume exceeds 20%, NOx emissions remain at a low level, staying below 500 ppm. Concurrently, as the rate of EGR volume increases from 5% to 30%, there is a corresponding rise in unburned methane emissions, with the maximum surge observed from 343 ppm to 21 021 ppm. Additionally, CO emissions increase as the rate of EGR volume increases, reaching 989 ppm in case 3. While in case 2, there is an initial ascent to 1381 ppm, followed by a decline to 1148 ppm, and ultimately, a subsequent rise.