Sustainable Energy & Fuels最新文献

Food waste is abundant and holds great potential to be converted into valuable chemicals like ethylene glycol (EG), which is a key compound for the production of commodity polymers and other specialty products. Therefore, the direct conversion of food waste could represent a pivotal alternative for the sustainable production of EG. Nickel-tungsten catalysts supported on glucose-derived carbons were synthesized and evaluated for EG direct production from cellulose and cellulosic urban wastes. A remarkable yield of EG of 62% was attained directly from cellulose after 5 h, while the optimized catalyst allowed to reach notable EG yields around 40% from cellulosic wastes. Furthermore, as far as we are concerned, no previous works have reported the conversion of food wastes, such as fruit peels, directly into EG. Therefore, we report the environmentally friendly production of EG from banana peel, orange peel and spent coffee grounds with promising yields of up to 21%.

A variety of passivation molecules have enhanced the performance and stability of organic–inorganic lead halide perovskite solar cells (PSCs); however, the tailoring of the design of these molecules remains largely unexplored. In this work, we propose two new classes of passivation molecules: a C₂-symmetric syn-type bifacial donor–π–donor molecule and a C₃-symmetric syn-type bifacial truxene. The former (PM-syn) bears hydrophobic alkylphenols and hydrophilic diethylene glycol-substituted phenyls on each face of the indenofluorene π-core. Owing to the efficient hole transfer and surface passivation by the flanked donor units, PM-syn (a racemate of enantiomers) exhibited an improved power conversion efficiency (PCE) of 18.79% and long-term stability compared with the control device (17.98%). The latter, bifacial truxene (TRX-syn), appended with three carboxyl units on one face, exhibited an improved PCE (19.76%) and stability, demonstrating the general effectiveness of the bifacial molecular concept in the passivation of PSC. Comparative spectroscopic and time-resolved studies of bifacial molecules and their anti-type analogues support our claims and provide a rich area for the design of new molecules for the modification of perovskite layers.

The ever-growing problem of the energy crisis can be addressed with the development of sustainable and renewable sources of energy. The naturally occurring hydrogenases with their active sites provide us with a blueprint to mimic the reaction pathway and mechanism of hydrogen production. This work presents an in-depth summary of the photocatalytic hydrogen production employing 4d/5d-T-metal complexes, quantum dots, and organic dyes as photosensitizers (PSs) and hydrogenase mimics as catalysts. This review is focused on the careful design of both the PSs and catalysts to enhance the overall catalytic activity of artificial photosynthetic systems. The paths followed during the photoinduced electron transfer including the active sites of the catalysts, are discussed to guide the design of robust and efficient photocatalytic hydrogen production systems. The reduction potentials of the catalysts and PSs, change in the free energy values and density functional theory (DFT) calculations are discussed to assess the thermodynamic feasibility of the photoinduced electron transfer processes.

In the field of solar energy applications, ion migration is a significant challenge. A promising solution to tackle this issue is through the Ionovoltaic Electricity Generator (IEG) effect observed in two-dimensional (2D) lead-free halide perovskite structures equipped with lateral electrodes. These devices with millimeter-spaced lateral electrodes generate electricity through moisture absorption. As moisture is absorbed, it creates an uneven distribution of ions, establishing a gradient that prompts ion migration. This migration generates a voltage difference across the electrodes, which in turn propels electrons through an external circuit, producing electrical power. Furthermore, humidity plays a crucial role in enhancing power generation by aiding in ion formation. In this study, we successfully synthesized mixed alloys of antimony and bismuth in the form of nanosheets of Cs₃SbBiBr₉ using a solution-based approach. The Cs₃SbBiBr₉ device, covering an area of 0.3 cm² (1.5 cm × 0.2 cm), demonstrated an open-circuit voltage (V_oc) of 0.22 V and a short-circuit current (I_sc) of 35 μA at 85% relative humidity (RH).

In addressing global energy demands, the focus on hydrogen gas production from renewable sources intensifies. This research review investigates hydrogen production via steam splitting using eutectic molten hydroxide (NaOH–KOH%) electrolysis, a promising solution for escalating energy needs. A pivotal aspect involves developing a novel reference electrode for eutectic molten hydroxide, enveloping Ni/Ni(OH)₂ with an alumina or mullite tube ionic membrane. The mullite-covered electrode proves stable and reusable from 225 to 300 °C, showcasing a novel advancement in electrochemical stability. Compared to silver and platinum quasi-reference electrodes, the designed reference electrode demonstrates superior stability and efficacy in controlling the platinum working electrode, marking a significant innovation. Moreover, an intriguing cyclic voltammetry study examines different working electrodes, including Ni, Pt, Ag, Mo, and stainless steel (SS) in eutectic molten hydroxide at different temperature conditions. The observed reduction potential for hydrogen evolution follows the order: Ni > Pt > Ag > SS > Mo, corroborated by chronoamperometry, underscoring the reliability of the findings. In the pursuit of high-temperature eutectic molten hydroxide electrolysis to split steam into hydrogen fuel, cathodes of nickel, platinum, and stainless steel are deployed alongside stainless steel and graphite anodes. Operating within the temperature range of 225 to 300 °C and applying voltages ranging from 1.5 to 2.5 V, stainless steel as an anode yields impressive current efficiencies at 300 °C: 90.5, 80 and 68.6% for nickel, stainless steel, and platinum cathodes, respectively. This study positions steam splitting via molten hydroxides as a promising alternative for hydrogen production, poised for integration with renewable energy sources, marking a transformative step in sustainable energy practices.

This study presents a novel approach to hydrogen evolution through ammonia borane dehydrogenation, utilizing the unique properties of upconverted nanoparticles (UCNPs) and safe, abundant near-infrared (NIR) light. By converting low-energy 980 nm NIR photons into high-energy visible photons, UCNPs offer a significant enhancement in catalytic activity. The fabrication of polystyrene-incorporated UCNPs (PS@UCNPs) prevents catalyst agglomeration and breakage, resulting in a 35-fold increase in activity compared to bare UCNPs. This increase is due to the high-energy emitted photons providing sufficient energy for hydrogen evolution, thereby reducing catalyst costs and eliminating the need for intermediate catalysts. The study also explores platinum-coated UCNPs (Pt@UCNPs), which increase photon absorption by platinum nanoparticles, significantly boosting photocatalytic performance. Pt@UCNPs demonstrated 25 times higher activity than PS@UCNPs, attributed to the unique properties of Pt nanoparticles. The activation energies for PS@UCNPs and Pt@UCNPs were 27.5 kJ mol⁻¹ and 48.8 kJ mol⁻¹, respectively, highlighting the synergistic effect of UCNPs utilizing NIR light and Pt utilizing visible light. Reaction kinetics indicated that hydrogen evolution rates increased with both catalyst and ammonia borane concentrations under NIR light. Recyclability tests confirmed the superior stability and durability of PS@UCNPs over Pt@UCNPs, with consistent hydrogen evolution rates across five cycles and minimal degradation. These findings position PS@UCNPs as a robust catalyst system with significant potential for long-term applications, contributing to the broader field of photochemical catalysis and inspiring further innovations in renewable energy systems. As materials and technologies continue to evolve, NIR-activated photocatalytic processes are expected to play a crucial role in the transition to a sustainable energy future, significantly impacting renewable energy and green chemistry.

Perovskite solar cells (PSCs) with an n–i–p configuration have demonstrated rapid progress in the past few years, though the most efficient devices were made using a doped small molecular hole-transport material, spiro-OMeTAD, which deteriorates their long-term stability. To address this problem, dopant-free hole transport materials should be developed. Herein, we present the synthesis and characterization of poly(4-(5′-(16-(3,4′-bis(2-ethylhexyl)-[2,2′-bithiophen]-5-yl)pyranthrene-8-yl)-3′,4-bis(2-ethylhexyl)-[2,2′-bithiophen]-5-yl)benzo[c][1,2,5]thiadiazole) (PATTBTT), which is considered as a promising hole-transport material for PSCs. The designed copolymer PATTBTT delivered a power conversion efficiency of 17.6% in PSCs, which was higher than those obtained for reference devices fabricated using dopant-free polytriarylamine-based hole-transport materials. These results demonstrate that pyranthrene-based conjugated polymers represent a promising new family of materials for high-efficiency perovskite solar cells.

Hybrid heterojunction solar cells (HHSCs) of an organic conjugate polymer, namely, poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) and silicon have received extensive attention due to their high efficiency (PCE) and low-temperature processing. However, effective collection of charge carriers from the PEDOT:PSS/n-Si interface is a challenging task due to various defects and low band offset at the interface. The current study explores ways of overcoming the limitations of HHSCs and unveils the potential of solution-processed graphene oxide (GO) thin capping layer for achieving high-efficiency and stable PEDOT:PSS/n-Si HHSCs. It also unveils the GO-induced tuning of the band bending at the interface and thus improved carrier selection. Moreover, it facilitated improved charge transportation in the PEDOT:PSS via screening the PEDOT–PSS interaction, as evidenced by a significant improvement (>2-fold) in the electrical conductivity of the PEDOT:PSS layer after applying the GO layer. The integration of the GO capping layer reduced the optical reflection to <8% and enhanced the Si surface passivation by >2 fold. The cumulative effect of GO capping led to a ∼2.4% absolute enhancement in the PCE with respect to the device without any GO layer. The champion GO/PEDOT:PSS/n-Si HHSCs exhibited a PCE of 11.66% in a simple device design on a low-cost solar-grade Si wafer. Moreover, the GO capping facilitated environment protection to the PEDOT:PSS, increasing the stability of the device under atmospheric conditions, thus revealing the great potential of the thin GO layer for highly efficient and stable HHSCs.

Correction for ‘Tribo-piezoelectric nanogenerators for energy harvesting: a first-principles study’ by Jemal Yimer Damte et al., Sustainable Energy Fuels, 2024, https://doi.org/10.1039/D4SE00498A.

Highly efficient and stable bifunctional electrocatalysts for total water splitting are crucial for the realization of large-scale hydrogen production. In this study, we successfully synthesized CeO_x-modified CoCr_yFe_2−yO₄ nanorod array structures on a nickel foam substrate via two-step hydrothermal method followed by calcination. It is demonstrated that Cr doping increases the electrical conductivity of the catalyst, which allows for a larger number of electrochemically accessible active sites at the catalyst terminals, thereby improving its activity. Modification of the CoCr_yFe_2−yO₄/NF surface with oxygen vacancy-rich CeO_x resulted in a highly efficient and stable bifunctional catalyst (CoCr_yFe_2−yO₄@CeO_x/NF), and the exceptional bifunctional activity and stability can be attributed to: (i) Cr doping and CeO_x modification induced a self-assembly transformation of the catalyst morphology from a nanosphere structure to a nanorod array structure, resulting in an increased specific surface area; (ii) the high conductivity especially in CoCr_0.6Fe_1.4O₄, allows electrochemical access to a greater number of active sites at the catalyst periphery; (iii) the introduction of abundant oxygen vacancies by CeO_x modification, which alters the electronic structure of CoCr_yFe_2−yO₄, leading to electron redistribution of Co, Cr and Fe, shifting them to higher oxidation states favorable for catalytic reactions. This promotes the formation of highly catalytically active metal oxyhydroxides on the CoCr_yFe_2−yO₄ surface during the OER process, thereby enhancing the catalytic efficiency.