Sustainable Energy & Fuels最新文献

Argon, a protective gas, is susceptible to contamination by impurity gases in the production of monocrystalline silicon for solar cells. Chemical looping combustion (CLC) technology offers a solution for argon recycling by leveraging the cyclic conversion of oxygen carriers. However, the desorption of low-concentration impurity gases requires high-activity oxygen carriers, and current screening methods primarily rely on experimental trial and error, which is time-consuming and labor-intensive. Herein, we propose machine learning-assisted Density Functional Theory (DFT) for high-throughput screening of oxygen carriers. Quaternary iron-based spinel oxygen carriers A1_xA2_1−xB_yFe_2−y were used as the object of study. DFT calculations were conducted on 756 oxygen carriers, while the remaining 3619 were predicted through machine learning, achieving a prediction accuracy R² of 0.87. Based on these predictions and a three-step screening criterion of synthesizability, thermodynamic stability, and reactivity, Cu_0.875Ni_0.125Al_0.5Fe_1.5O₄ exhibited the highest reactivity and its desorption of impurity gases is 6 times higher than that of fresh Fe₂O₃. In the stability test, Cu_0.875Ni_0.125Al_0.5Fe_1.5O₄ maintained 96% CO removal efficiency after 10 cycles, facilitating the cyclic purification of crude argon. This study provides new guidance for the design and discovery of high-activity materials through high-throughput screening.

Correction for ‘Photocatalytic CO₂ reduction to methanol integrated with the oxidative coupling of thiols for S–X (X = S, C) bond formation over an Fe₃O₄/BiVO₄ composite’ by Nitish Saini et al., Sustainable Energy Fuels, 2024, 8, 1750–1760, https://doi.org/10.1039/D3SE01651J.

This study unveils a highly efficient electrocatalyst based on hydrated ammonium metal phosphates (NH₄MPO₄·H₂O) with a layered crystal structure and expanded interlayer spacing, facilitating rapid electron and ion transport for advanced oxygen evolution reaction (OER) applications. Addressing inherent limitations in conductivity and electroactive surface area, we engineered a heterostructured electrocatalyst by combining NH₄NiPO₄·H₂O with CdIn₂S₄ and in situ formed Ni₃S₂ on nickel foam (NF) through a two-step hydrothermal process. The resulting NH₄NiPO₄·H₂O/CdIn₂S₄/Ni₃S₂ (NPO/CINS) system leverages phosphate–sulfide interfacial interactions, significantly enhancing catalytic performance. Electrochemical tests reveal impressive OER and urea oxidation reaction (UOR) activities, achieving low overpotentials of 245 mV and 1.26 V at 10 mA cm⁻², respectively. The obtained exceptional UOR efficiency exceeds that of previously reported oxide and sulfide-based heterostructure electrocatalysts. The NPO/CINS heterostructure demonstrates remarkable stability towards OER, with only 2% degradation over 65 hours of continuous operation, affirming its durability for high-performance applications. This work emphasizes the power of synergistic interfacial bonding, optimized electron transfer, and strategic structural design, positioning the NPO/CINS heterostructure as a pioneering catalyst for scalable energy solutions.

The electrochemical glycerol oxidation reaction (GOR) offers a dynamically favourable pathway to transform biomass byproducts into value-added chemicals such as formic acid, glycolic acid, glyceraldehyde, and glyceric acid. This approach offers a more efficient utilization of glycerol and might fulfil the anticipated future demands for formic acid, and which serves as a potential fuel for both direct and indirect formic acid fuel cells. However, the current challenge lies in the low oxidation activity and conversion ratio exhibited by existing catalysts. Herein, an amorphous Co₃O₄–CuO/CN_x-300 composite on a carbon cloth was fabricated, which shows high activity toward electrochemical glycerol oxidation with a very low potential of 1.25 V (RHE) at 10 mA cm⁻² and a very high faradaic efficiency of about 91% (formic acid = 81% and glycolic acid = 10%) at 1.5 V (RHE) potential for oxidative product formation with a high selectivity of 89% for formic acid production. Furthermore, the as-prepared Pt/C‖Co₃O₄–CuO/CN_x-300 electrolyzer required 260 mV less potential compared with conventional water splitting to achieve a current density of 10 mA cm⁻². In addition, the electrolyzer was stable at a cell potential of 1.7 V for up to 60 hours, reducing the energy consumption of traditional water splitting by ∼15.48%. The high GOR performance of Co₃O₄–CuO/CN_x-300 is attributed to the synergistic interaction between its components, its amorphous structure, and its high surface area. This study offers fascinating insights for designing cost-effective transition metal-based electrocatalysts, aiming to facilitate glycerol oxidation for the production of value-added chemicals while boosting efficient cathodic hydrogen evolution with minimal energy depletion.

Photothermal catalysis has garnered significant attention as a potential solution to address energy scarcity. In photothermal catalysis, light irradiation directly heats the catalyst bed, inducing a localized temperature gradient. However, in methane reforming reactions such as dry reforming, the undesired reverse reaction typically proceeds in the lower temperature zone of the catalyst bed, which reduces the overall efficiency. To address this issue, we developed a novel flow-type photo-reactor composed of a quartz tube and a quartz filler welded within the tube. The narrow catalyst-filled gap was used for catalytic reaction that minimizes the temperature gradient under light irradiation. The developed reactor, termed the gap reactor, demonstrated excellent catalytic performance in photothermal dry reforming of methane (PT-DRM), achieving ∼70–80% conversion of CH₄ and CO₂ over 100 hours using a SiO₂-encapsulated Co–Ni alloy catalyst previously developed by our group. Compared to the conventional quartz tube reactor with the same cross-sectional area for light absorption, the gap reactor significantly enhanced both conversion and stability. Furthermore, integrating the gap reactor with steam addition to the reaction feed successfully suppressed coke formation to only 0.6 wt% after approximately 50 hours of reaction. This study highlights the benefits of the gap reactor design in high-temperature catalytic applications up to 1000 °C.

To improve the performance of direct ethanol fuel cells (DEFCs), which are hindered by traditional catalysts, having matters pertaining to stability, activity, and selectivity in reaction environments, various electrocatalysts such as Pd/Ni₂P, Pd/MoS₂, and Pd/Ni₂P–MoS₂ were synthesized using the microwave-assisted NaBH₄–ethylene glycol reduction method. The research findings suggest that the Pd/Ni₂P–MoS₂ catalyst we developed had the highest activity (1579 mA mg_Pd⁻¹), approximately 21 times greater than that of commercial Pd/C. The stability of the electrocatalysts were examined using chronoamperometry (CA) and cyclic voltammetry (CV) measurements, which indicated that the Pd/Ni₂P–MoS₂ electrocatalyst had good stability towards the ethanol oxidation reaction (EOR) in alkaline electrolyte. Electrochemical impedance spectroscopy (EIS) analysis showed that the Pd/Ni₂P–MoS₂ electrocatalyst had lower charge transfer resistance, indicating better electrochemical kinetics. According to XRD, HR-TEM, XPS, and electrochemical analysis, the enhanced electrocatalytic activity, long-term stability of the Pd/Ni₂P–MoS₂ electrocatalyst were attributable to the interface synergism as well as electronic and strain effects between the Pd, Ni₂P, and MoS₂ interactions. This resulted in a downshift in the d-band center of the Pd/Ni₂P–MoS₂ electrocatalyst, weakening intermediate adsorption and the adsorbate metal interaction.

Enhancing charge storage and balancing energy and power densities in a supercapacitor requires a hybrid approach. To this end, a material with high porosity, good crystalline stability, and an adjustable framework could be integrated with a 2D defect-containing material that has a large surface area. A hydrothermally synthesized Zn(II)-based coordination polymer, [Zn(IPA)₂(2-MI)₂]_n (MZ) [IPA: isophthalic acid, 2MI: 2-methylimidazole], and in situ fabricated heterocomposites with MZ anchored on graphene oxide (GO) and reduced graphene oxide (RGO) interlayer sheets are presented here. MZ and its heterocomposites were characterized using spectroscopic (SC-XRD for MZ, UV-visible, FT-IR, PXRD with Rietveld refinement, and XPS) and nanoscopic (FE-SEM with EDX, and HR-TEM) techniques to confirm their structural compositions. The topological underlying net of MZ shows the uninodal 2C1 net topology. The synergistic effect between MZ and GO/RGO delivered good supercapacitance (SC) properties. Three electrode-based electrochemical analysis (1 M KCl, 1 M KOH, 1 M Na₂SO₄) revealed that GMZ23 and RGMZ11 exhibited better performance in 1 M KCl aqueous electrolyte than MZ. Furthermore, symmetric (SSC) and asymmetric supercapacitor (ASC) devices were designed and tested. The RGMZ11 ASC device provided the specific capacitance (Sp. Cp.) of 154.53 F g⁻¹ (specific capacity-247.48 C g⁻¹), the energy density (E. D.) of 54.99 W h kg⁻¹, and the power density (P. D.) of 160 W kg⁻¹ at a 0.2 A g⁻¹ current density in 1 M TEABF₄ (DMSO) electrolyte. Up to 75% of the capacitance of RGMZ11 was retained after 10 000 charge–discharge cycles at a current density of 5 A g⁻¹. Moreover, the capacitive and diffusion-controlled processes were examined using the Dunn method and it was found that the optimized device follows a diffusion-controlled process at lower scan rate. The optimized RGMZ11 was successfully utilized to make a multi-color disco LED and a red LED glow. The above study suggests that the RGMZ11 heterocomposite shows good performance for SC applications.

Precursor structure engineering is a fundamental strategy for regulating the physicochemical properties of g-C₃N₄, which can promote the development of efficient photocatalysts. Herein, hexamethylenetetramine (HMTA) with a stable three-dimensional cage-like spatial configuration, was successfully incorporated into a melamine–cyanuric acid supramolecular complex via a hydrothermal method. Furthermore, a novel N-defect-rich porous g-C₃N₄ was obtained through thermal pyrolysis of this HMTA-regulated supramolecular precursor. The presence of N defects and the resulting midgap states which were proved to be induced by HMTA-regulated precursor structure engineering could effectively enhance the light absorption and promote the separation of photogenerated carriers of g-C₃N₄. As a result, the HMTA-regulated g-C₃N₄ exhibited an enhanced H₂-evolution activity of 2.77 mmol g⁻¹ h⁻¹, which was 5.8 times that of pristine g-C₃N₄. This work proposes a molecular-level structure engineering strategy of g-C₃N₄ by rationally incorporating functional molecules into the precursor, offering valuable insights for developing highly efficient photocatalysts.

Dye-sensitized photoelectrochemical cells (DS-PECs), devices inspired by photosynthesis, are being developed to advance the goal of using the sun as the sole source of energy for converting abundant resources to fuel and valuable chemicals. Herein, we report compact and vertically aligned titanium dioxide nanotubes grown through self-organized electrochemical anodization as semiconducting materials functionalized with a molecular copper(I) bis(diimine)-based acceptor–chromophore–donor to yield a photoanode capable of carrying out oxidative processes. The ability of these dye-sensitized photoanodes to drive oxidative processes is further confirmed photoelectrochemically through activation of a molecular iridium(III) water oxidation pre-catalyst where ultimately a Faradaic efficiency of 84% is found for O₂ production.

The quest to find an effective non-precious metal-based catalyst for the hydrogen evolution process has recently garnered widespread attention. Platinum (Pt) and other platinoids are the preferred catalyst for the hydrogen evolution reaction (HER). However, their widespread application is restricted by the scarcity of rare earth reserves and the consequent elevated costs. In this work, we synthesized a distinctive 1T/2H phase structure via a facile hydrothermal technique. Pristine MoSe₂ and Cu–MoSe₂ were deposited on a carbon cloth (CC) and were directly employed as electrodes in HERs, without the use of binders. The structures and basal planes of the as-prepared pristine MoSe₂@CC as well as 3% and 5%Cu–MoSe₂@CC samples were analysed via XRD, and their morphology was examined using field emission scanning electron microscopy (FESEM), revealing that each carbon fibre's surface was evenly covered with wrinkled nano petals in the shape of nanosheets. Elemental mapping using energy dispersive X-ray spectroscopy (EDX) revealed the coexistence of Cu, Mo, and Se, uniformly dispersed over the sample, and their corresponding energy states and binding energies were analysed using X-ray photoelectron spectroscopy (XPS). Findings indicated a substantial reduction in binding energy when copper was present on MoSe₂, which caused the metallic-semiconductor (1T/2H) phase to dominate. This meticulously developed architecture when coated on a carbon fibre substrate exhibited remarkable HER activity with a low onset potential of −113 mV vs. RHE (reversible hydrogen electrode), a Tafel slope of 87.2 mV per decade and excellent cycle stability of 80 h. In addition, density functional theory (DFT) studies conducted on the novel structure predicted that the introduction of Cu⁺ ions into the MoSe₂ monolayer can make interfacial semiconducting MoSe₂ transform into metallic MoSe₂. This transformation is beneficial for speeding up charge transfer between the interfaces, promoting H atom adsorption and desorption kinetics and thus accelerating sluggish HER kinetics, thereby enhancing its catalytic performance. In brief, the present findings provide experimental and theoretical insights into developing advanced functional catalysts using phase engineering for energy-conversion applications.