Sustainable Energy & Fuels最新文献

Lithium-ion batteries (LIBs) present the highest gravimetric and volumetric energy density, among the different rechargeable battery systems on the market, but still present safety and environmental issues. Thus, batteries based on different chemistries are being explored. Zinc–manganese oxide batteries represent a promising approach since they use components that are more readily available and accessible, especially in light of the scarcity of resources such as lithium. This review focusses on separator materials and the corresponding interface layers for zinc–manganese oxide batteries, from theoretical and experimental points of view, providing an overview of the most recent studies and advancements in the field. The primary obstacles still limiting the widespread application of these batteries are also covered.

Waste-derived Ni-based LDHs (layered double hydroxides) provides a sustainable solution for generating green hydrogen while addressing hazardous waste challenges. The OER (oxygen evolution reaction) features an exchange of four electrons through the production of several precursors in an environment-friendly way. This review objectively evaluates Ni-based waste-derived LDHs and their design and functionalization approaches, followed by an overview of the existing waste transformation possibilities for OER processes. This review additionally emphasises the mechanistic routes of OER with Ni-based LDHs, along with its potential applications in sustainable syntheses of green hydrogen. The problems and prospects of this rapidly emerging field are also critically explored. It is expected that this review will provide valuable knowledge on waste-derived Ni–Ti LDHs for long-term green hydrogen production.

Organic/inorganic hybrid perovskite solar cells (PSCs) still face significant challenges related to carrier recombination caused by numerous defects and an unfavorable energy level alignment. In this study, we introduce a multifunctional p-type organic molecule, dioctylbenzothieno[2,3-b]benzothiophene (C8BTBT), as an additive, aimed at enhancing the device performance. Our investigation reveals that the incorporation of C8BTBT effectively enhances perovskite crystalline quality, diminishes nonradiative recombination, improves perovskite electrical properties and optimizes energy level alignment. These improvements collectively contribute to the advancement of PSC devices. Impressively, a remarkable power conversion efficiency (PCE) exceeding 22% is achieved, accompanied by an open-circuit photovoltage of 1.12 V, a short-circuit photocurrent density of 24.58 mA cm⁻², and a fill factor of 0.80. Furthermore, we evaluate the long-term stability of unencapsulated devices over 1000 hours under ambient conditions (with a temperature of 20 °C and humidity of 30%). The PSCs incorporating C8BTBT demonstrate a normalized PCE retention of 93% compared to their initial performance, while the control devices retain 82% of their initial efficiency.

Canadian hardwood and softwood species were screened for hydrothermal liquefaction to produce sustainable biocrude. Based on the availability of the feedstock, their biocrude yield, and oxygen content, spruce (softwood) and poplar (hardwood) species were found to be promising and selected for the optimization of process parameters to maximize biocrude yield while minimizing the oxygen content. Solvent (ethanol) assisted hydrothermal liquefaction was performed to evaluate the effect of process parameters such as temperature, retention time, catalyst loading, and different ethanol concentrations. The highest yield of biocrude obtained from spruce and poplar was ∼36 wt% with an HHV of ∼27 MJ kg⁻¹ under the optimized HTL conditions. HTL experiments were conducted to study the effect of recycling the hydrothermal liquefaction aqueous phase and co-liquefaction of hardwood and softwood species. The HTL aqueous phase recycling improved the quantity (47 wt%) and quality (HHV of 29.9 MJ kg⁻¹) of the biocrude obtained from spruce liquefaction. The co-liquefaction of spruce and poplar (50 : 50 wt%) showed a potential synergistic effect on biocrude yield and quality at a lower reaction temperature (260 °C). The GC-MS analysis of spruce and poplar wood biocrude indicated that the majority of the compounds were phenolic in nature. BET results confirmed the high surface area of spruce and poplar wood-derived hydrochar. The gaseous products formed during HTL were mainly composed of CO₂, CO, H₂, O₂, CH₄, and C₂H₂.

Solid state electrolytes, which replace flammable liquid ones, are seen as being key to deployment of safe and high capacity batteries based on lithium metal anodes. Yet these materials often suffer from poor electrode/electrolyte contact which limits Li⁺ transport and active material utilisation. To overcome these barriers, effective methods to intimately connect active materials and electrolytes must be developed and demonstrated. In this work gradient composite cathodes of lithium iron phosphate (LFP) and polyethylene oxide (PEO) were manufactured using spray deposition to remove the planar electrode/electrolyte interface in solid-state batteries with polymeric electrolytes. These graded cathodes achieved ten times lower resistance and superior cycle life and rate testing performance compared to ungraded cathodes made in the same way. Graded composite cathodes maintained stable capacity after 80 cycles and functioned well at rates up to 2C, whereas ungraded composite cathodes failed to deliver any useable capacity after 80 cycles and at rates higher than C/5. Hence, this work acts as a demonstration that simple electrode structuring can have a significant impact on cell performance, offering a route towards the stabilization of solid-state batteries in real-world applications.

Surface of a particulate-Cu_0.8Ag_0.2GaS₂-based photocathode was co-modified with ZnS and Ag, resulting in improvement in the performance of the Cu_0.8Ag_0.2GaS₂ photocathode for syngas (H₂ + CO) formation through photoelectrochemical H₂O and CO₂ reduction under visible light in an aqueous electrolyte. Bubbles of the syngas were visually observed over the developed Ag and ZnS-co-modified Cu_0.8Ag_0.2GaS₂ photocathode at 0 V vs. RHE at the applied potential using a 300 W Xe-arc lamp (λ > 420 nm). Based on various control experiments and characterization studies, the following two crucial factors have arisen: (1) formation of a (ZnS)–(Cu_0.8Ag_0.2GaS₂) solid-solution near the surface of Cu_0.8Ag_0.2GaS₂ particles was vital for enhancing the separation of the photogenerated carriers, (2) the Ag cocatalyst loaded on the solid-solution worked as an active site for photoelectrochemical CO₂ reduction. Moreover, artificial photosynthetic syngas formation using water as an electron donor under simulated sunlight without any external bias was demonstrated by combining the developed Ag/ZnS/Cu_0.8Ag_0.2GaS₂ photocathode with a CoO_x-loaded BiVO₄ photoanode.

Environmental changes and climate concerns dictate the necessary transition to sustainable technologies based on green reactions. At the same time, catalysts for carbon dioxide reduction, nitrogen fixation and other electrochemical reactions should be cheap and stable, while exhibiting high selectivity and efficiency. Electrocatalytic reactions make it possible to obtain industrial products under ambient conditions, but this is still difficult and expensive. In the last few years, tremendous progress has been made in the study and application of triazine-based frameworks as catalytic systems and beyond without the use of expensive metals. This short perspective review mainly examines studies not older than five years (more than 75% of citations), with special emphasis being placed on the analysis of the latest research over the last two years (more than 30% of citations). It has been shown that the use of triazines is effective in the reactions of hydrogen evolution (HER), water splitting, oxygen evolution (OER), CO₂ reduction (CO₂RR), ammonia production (NO₃RR and NRR), etc. Based on this analysis, conclusions are drawn about the effectiveness of catalysts and the ways to increase their efficiency. In the near future, we should expect a breakthrough in increasing the hydrophilicity and porosity of triazine catalyst samples, as well as in the use of media in the form of ionic liquids and machine learning and computer modeling of electrode designs.

Thermoelectric (TE) materials are able to convert heat into electricity. Suitable TE materials should have high power factors (PFs) and low thermal conductivities, where PF = S²σ, with S being the Seebeck coefficient and σ the electrical conductivity. Most recent improvements in TE materials have been achieved by the reduction of the thermal conductivity, and strategies to improve the PF have been minor. Recently, our group reported a new concept to significantly increase the PF, based on the combination of a porous TE solid with an electrolyte. Herein, we made use of this new approach but using polyelectrolytes, rather than the liquid electrolytes previously employed. Poly(diallyldimethylammonium X) polyelectrolytes were tested, where X = Cl⁻ (C) or tosylate (Tos). An average PF improvement of 2.6 times was obtained when PDADMAC was used, similar to the enhancement with liquid electrolytes. This was due to average decreases of 13% and 71% in the absolute value of the Seebeck coefficient and the electrical resistance of the system, respectively. An electrochemical study by impedance spectroscopy and cyclic voltammetry revealed the better capability of PDADMAC to screen the charge introduced in the oxide compared with that of PDADMATos. The resistance reduction for PDADMAC was attributed to variations in the carrier concentration in the oxide after its equilibration with the polyelectrolyte. The notable PF improvement obtained paves the way for the use of polyelectrolytes to fabricate all-solid-state solid-electrolyte systems with enhanced PFs.

Hydrogen is an eco-friendly and renewable energy source with high energy density per mass and is expected to be an alternative to fossil fuels. As a main component derived from biomass, acetic acid (HAc) shows potential in green hydrogen production via auto-thermal reforming (ATR) of HAc. In the ATR process, although Ni-based catalysts exhibited high activity for the conversion of HAc, issues of oxidation, sintering and coking remain to be addressed. Therefore, nickel-based catalysts loaded on the Sm₆WO₁₂ tungstate structure were fabricated by the co-precipitation method, and the structure–reactivity relationship was explored. The characterization results showed that a stable Sm₆WO₁₂ tungstate structure was formed after the introduction of W species in Sm oxides, promoting reduction and dispersion of Ni on the catalyst surface with a high Ni⁰/(Ni⁰ + Ni²⁺) ratio of NSW20 at 40.8%. Meanwhile, abundant oxygen vacancies were formed in the tungstate structure, which accelerated the conversion of reactants H₂O and O₂ into active oxygen species (O*), and enhanced the oxidation of coking precursors (C*), thereby efficiently inhibiting coking of the catalyst. As a result, the NSW20 catalyst with a Sm₆WO₁₂ support exhibited high catalytic activity in the ATR process: the conversion of HAc was stable at 100.0%, and the yield of hydrogen was maintained near 2.42 mol-H₂ per mol-HAc, while the apparent activation energy (E_a) and turnover frequency (TOF-H₂) were recorded to be 43.5 kJ mol⁻¹ and 2.38 × 10⁻² s⁻¹, respectively.

Current solar photovoltaic (PV) installation rates are inadequate to combat global warming, necessitating approximately 3.4 TW of PV installations annually. This would require about 89 million tonnes (Mt) of glass yearly, yet the actual production output of solar glass is only 24 Mt, highlighting a significant supply shortfall (3.7 times). Moreover, there is scarce information about the iron content of many sand deposits worldwide. Low-iron sand is required for PV glass production, to make the glass highly transparent and reduce the absorption of solar energy. Additionally, glass manufacturing leads to significant emissions, with fossil fuels being the primary energy source. Recycling offers a promising partial solution, with some available techniques enabling the clean recovery and reuse of end-of-life PV glass (cullet) for new panels. Similarly, methods such as the Hot Knife and Delam processes could recover entire glass cover sheets for potential reuse in new PV modules. Furthermore, there is an opportunity to establish new glass factories with lower emissions through strategies such as hydrogen fuel adoption, electrification, and waste heat recovery.