Molecules

Editorial

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2 pages, 187 KiB

Open AccessEditorial

The Chemistry of Sustainable Energy Conversion and Storage

by Guanglin Xia

Molecules 2022, 27(12), 3731; https://doi.org/10.3390/molecules27123731 - 10 Jun 2022

Cited by 1 | Viewed by 1119

Abstract

The long-term environmental side-effects and finite supply of fossil fuels, which dominate the energy resources in our daily lives, require a transition to renewable and clean energy resources [...] Full article

(This article belongs to the Special Issue The Chemistry of Sustainable Energy Conversion and Storage)

Research

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12 pages, 2167 KiB

Open AccessArticle

Laser-Induced Interdigital Structured Graphene Electrodes Based Flexible Micro-Supercapacitor for Efficient Peak Energy Storage

by Apurba Ray, Jenny Roth and Bilge Saruhan

Molecules 2022, 27(1), 329; https://doi.org/10.3390/molecules27010329 - 5 Jan 2022

Cited by 26 | Viewed by 4466

Abstract

The rapidly developing demand for lightweight portable electronics has accelerated advanced research on self-powered microsystems (SPMs) for peak power energy storage (ESs). In recent years, there has been, in this regard, a huge research interest in micro-supercapacitors for microelectronics application over micro-batteries due [...] Read more.

The rapidly developing demand for lightweight portable electronics has accelerated advanced research on self-powered microsystems (SPMs) for peak power energy storage (ESs). In recent years, there has been, in this regard, a huge research interest in micro-supercapacitors for microelectronics application over micro-batteries due to their advantages of fast charge–discharge rate, high power density and long cycle-life. In this work, the optimization and fabrication of micro-supercapacitors (MSCs) by means of laser-induced interdigital structured graphene electrodes (LIG) has been reported. The flexible and scalable MSCs are fabricated by CO₂-laser structuring of polyimide-based Kapton ^® HN foils at ambient temperature yielding interdigital LIG-electrodes and using polymer gel electrolyte (PGE) produced by polypropylene carbonate (PPC) embedded ionic liquid of 1-ethyl-3-methyl-imidazolium-trifluoromethansulphonate [EMIM][OTf]. This MSC exhibits a wide stable potential window up to 2.0 V, offering an areal capacitance of 1.75 mF/cm² at a scan rate of 5.0 mV/s resulting in an energy density (E_a) of 0.256 µWh/cm² @ 0.03 mA/cm² and power density (P_a) of 0.11 mW/cm² @0.1 mA/cm². Overall electrochemical performance of this LIG/PGE-MSC is rounded with a good cyclic stability up to 10,000 cycles demonstrating its potential in terms of peak energy storage ability compared to the current thin film micro-supercapacitors. Full article

(This article belongs to the Special Issue The Chemistry of Sustainable Energy Conversion and Storage)

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10 pages, 3186 KiB

Open AccessArticle

Numerical Investigation of Graphene as a Back Surface Field Layer on the Performance of Cadmium Telluride Solar Cell

by Devendra KC, Deb Kumar Shah, M. Shaheer Akhtar, Mira Park, Chong Yeal Kim, O-Bong Yang and Bishweshwar Pant

Molecules 2021, 26(11), 3275; https://doi.org/10.3390/molecules26113275 - 28 May 2021

Cited by 19 | Viewed by 2858

Abstract

This paper numerically explores the possibility of ultrathin layering and high efficiency of graphene as a back surface field (BSF) based on a CdTe solar cell by Personal computer one-dimensional (PC1D) simulation. CdTe solar cells have been characterized and studied by varying the [...] Read more.

This paper numerically explores the possibility of ultrathin layering and high efficiency of graphene as a back surface field (BSF) based on a CdTe solar cell by Personal computer one-dimensional (PC1D) simulation. CdTe solar cells have been characterized and studied by varying the carrier lifetime, doping concentration, thickness, and bandgap of the graphene layer. With simulation results, the highest short-circuit current (I_sc = 2.09 A), power conversion efficiency (η = 15%), and quantum efficiency (QE~85%) were achieved at a carrier lifetime of 1 × 10³ μs and a doping concentration of 1 × 10¹⁷ cm⁻³ of graphene as a BSF layer-based CdTe solar cell. The thickness of the graphene BSF layer (1 μm) was proven the ultrathin, optimal, and obtainable for the fabrication of high-performance CdTe solar cells, confirming the suitability of graphene material as a BSF. This simulation confirmed that a CdTe solar cell with the proposed graphene as the BSF layer might be highly efficient with optimized parameters for fabrication. Full article

(This article belongs to the Special Issue The Chemistry of Sustainable Energy Conversion and Storage)

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10 pages, 2837 KiB

Open AccessArticle

Carbon Dioxide Reduction with Hydrogen on Fe, Co Supported Alumina and Carbon Catalysts under Supercritical Conditions

by Viktor I. Bogdan, Aleksey E. Koklin, Alexander L. Kustov, Yana A. Pokusaeva, Tatiana V. Bogdan and Leonid M. Kustov

Molecules 2021, 26(10), 2883; https://doi.org/10.3390/molecules26102883 - 13 May 2021

Cited by 13 | Viewed by 2407

Abstract

Reduction of CO₂ with hydrogen into CO was studied for the first time on alumina-supported Co and Fe catalysts under supercritical conditions with the goal to produce either CO or CH₄ as the target products. The extremely high selectivity towards methanation [...] Read more.

Reduction of CO₂ with hydrogen into CO was studied for the first time on alumina-supported Co and Fe catalysts under supercritical conditions with the goal to produce either CO or CH₄ as the target products. The extremely high selectivity towards methanation close to 100% was found for the Co/Al₂O₃ catalyst, whereas the Fe/Al₂O₃ system demonstrates a predominance of hydrogenation to CO with noticeable formation of ethane (up to 15%). The space–time yield can be increased by an order of magnitude by using the supercritical conditions as compared to the gas-phase reactions. Differences in the crystallographic phase features of Fe-containing catalysts cause the reverse water gas shift reaction to form carbon monoxide, whereas the reduced iron phases initiate the Fischer–Tropsch reaction to produce a mixture of hydrocarbons. Direct methanation occurs selectively on Co catalysts. No methanol formation was observed on the studied Fe- and Co-containing catalysts. Full article

(This article belongs to the Special Issue The Chemistry of Sustainable Energy Conversion and Storage)

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12 pages, 14437 KiB

Open AccessArticle

Cu₂O-Ag Tandem Catalysts for Selective Electrochemical Reduction of CO₂ to C₂ Products

by Di Niu, Cong Wei, Zheng Lu, Yanyan Fang, Bo Liu, Da Sun, Xiaobin Hao, Hongge Pan and Gongming Wang

Molecules 2021, 26(8), 2175; https://doi.org/10.3390/molecules26082175 - 9 Apr 2021

Cited by 20 | Viewed by 5261

Abstract

The electrochemical carbon dioxide reduction reaction (CO₂RR) to C₂ chemicals has received great attention. Here, we report the cuprous oxide (Cu₂O) nanocubes cooperated with silver (Ag) nanoparticles via the replacement reaction for a synergetic CO₂RR. The [...] Read more.

The electrochemical carbon dioxide reduction reaction (CO₂RR) to C₂ chemicals has received great attention. Here, we report the cuprous oxide (Cu₂O) nanocubes cooperated with silver (Ag) nanoparticles via the replacement reaction for a synergetic CO₂RR. The Cu₂O-Ag tandem catalyst exhibits an impressive Faradaic efficiency (FE) of 72.85% for C₂ products with a partial current density of 243.32 mA·cm⁻². The electrochemical experiments and density functional theory (DFT) calculations reveal that the introduction of Ag improves the intermediate CO concentration on the catalyst surface and meanwhile reduces the C-C coupling reaction barrier energy, which is favorable for the synthesis of C₂ products. Full article

(This article belongs to the Special Issue The Chemistry of Sustainable Energy Conversion and Storage)

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16 pages, 1875 KiB

Open AccessArticle

Preparation of Propanols by Glycerol Hydrogenolysis over Bifunctional Nickel-Containing Catalysts

by Alexander A. Greish, Elena D. Finashina, Olga P. Tkachenko and Leonid M. Kustov

Molecules 2021, 26(6), 1565; https://doi.org/10.3390/molecules26061565 - 12 Mar 2021

Cited by 6 | Viewed by 2148

Abstract

The paper presents the results obtained in studying glycerol hydrogenolysis into 1-propanol and 2-propanol over bifunctional Ni/WO₃-TiO₂ and Ni/WO₃-ZrO₂ catalysts in the flow system. Due to the optimal combination of acidic and hydrogenation properties of the heterogeneous [...] Read more.

The paper presents the results obtained in studying glycerol hydrogenolysis into 1-propanol and 2-propanol over bifunctional Ni/WO₃-TiO₂ and Ni/WO₃-ZrO₂ catalysts in the flow system. Due to the optimal combination of acidic and hydrogenation properties of the heterogeneous catalysts, they exhibit higher performance in glycerol conversion into C₃ alcohols, although the process is carried out in rather mild conditions. At the reaction temperature of 250 °C and hydrogen pressure of 3 MPa, the total yield of 1-propanol and 2-propanol reaches 95%, and the glycerol conversion is close to 100%. Full article

(This article belongs to the Special Issue The Chemistry of Sustainable Energy Conversion and Storage)

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16 pages, 2883 KiB

Open AccessArticle

Meso/Microporous Carbons from Conjugated Hyper-Crosslinked Polymers Based on Tetraphenylethene for High-Performance CO₂ Capture and Supercapacitor

by Mohamed Gamal Mohamed, Mahmoud M. M. Ahmed, Wei-Ting Du and Shiao-Wei Kuo

Molecules 2021, 26(3), 738; https://doi.org/10.3390/molecules26030738 - 31 Jan 2021

Cited by 80 | Viewed by 4521

Abstract

In this study, we successfully synthesized two types of meso/microporous carbon materials through the carbonization and potassium hydroxide (KOH) activation for two different kinds of hyper-crosslinked polymers of TPE-CPOP1 and TPE-CPOP2, which were synthesized by using Friedel–Crafts reaction of tetraphenylethene (TPE) monomer with [...] Read more.

In this study, we successfully synthesized two types of meso/microporous carbon materials through the carbonization and potassium hydroxide (KOH) activation for two different kinds of hyper-crosslinked polymers of TPE-CPOP1 and TPE-CPOP2, which were synthesized by using Friedel–Crafts reaction of tetraphenylethene (TPE) monomer with or without cyanuric chloride in the presence of AlCl₃ as a catalyst. The resultant porous carbon materials exhibited the high specific area (up to 1100 m² g⁻¹), total pore volume, good thermal stability, and amorphous character based on thermogravimetric (TGA), N₂ adsoprtion/desorption, and powder X-ray diffraction (PXRD) analyses. The as-prepared TPE-CPOP1 after thermal treatment at 800 °C (TPE-CPOP1-800) displayed excellent CO₂ uptake performance (1.74 mmol g⁻¹ at 298 K and 3.19 mmol g⁻¹ at 273 K). Furthermore, this material possesses a high specific capacitance of 453 F g⁻¹ at 5 mV s⁻¹ comparable to others porous carbon materials with excellent columbic efficiencies for 10,000 cycle at 20 A g⁻¹. Full article

(This article belongs to the Special Issue The Chemistry of Sustainable Energy Conversion and Storage)

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14 pages, 6153 KiB

Open AccessArticle

Improved Thermochemical Energy Storage Behavior of Manganese Oxide by Molybdenum Doping

by Javier Moya, Javier Marugán, María Orfila, Manuel Antonio Díaz-Pérez and Juan Carlos Serrano-Ruiz

Molecules 2021, 26(3), 583; https://doi.org/10.3390/molecules26030583 - 22 Jan 2021

Cited by 8 | Viewed by 1995

Abstract

To improve the thermochemical energy storage (TCS) behavior of Mn₂O₃, several Mn–Mo oxides with varying amounts of MoO₃ (0–30 wt%) were prepared by a precipitation method. The physico-chemical properties of the solids were studied by N₂ adsorption–desorption, [...] Read more.

To improve the thermochemical energy storage (TCS) behavior of Mn₂O₃, several Mn–Mo oxides with varying amounts of MoO₃ (0–30 wt%) were prepared by a precipitation method. The physico-chemical properties of the solids were studied by N₂ adsorption–desorption, X-ray diffraction (XRD), scanning electron microscopy (SEM), and H₂-temperature-programmed reduction (TPR), while their TCS behavior was determined by thermogravimetric analysis coupled with differential scanning calorimetry (TGA-DSC). Apart from Mn₂O₃ and MoO₃ phases, XRD revealed a mixed MnMoO₄ phase for MoO₃ loadings equal or higher than 1.5 wt%. All samples showed a well-formed coral-like surface morphology, particularly those solids with low MoO₃ contents. This coral morphology was progressively decorated with compact and Mo-enriched MnMoO₄ particles as the MoO₃ content increased. TPR revealed that the redox behavior of Mn₂O₃ was significantly altered upon addition of Mo. The TCS behavior of Mn₂O₃ (mostly oxidation kinetics and redox cyclability) was enhanced by addition of low amounts of Mo (0.6 and 1.5% MoO₃) without significantly increasing the reduction temperature of the solids. The coral morphology (which facilitated oxygen diffusion) and a smoother transition from the reduced to oxidized phase were suggested to be responsible for this improved TCS behavior. The samples containing 0.6 and 1.5 wt% of MoO₃ showed outstanding cyclability after 45 consecutive reduction–oxidation cycles at high temperatures (600–1000 °C). These materials could potentially reach absorption efficiencies higher than 90% at concentration capacity values typical of concentrated solar power plants. Full article

(This article belongs to the Special Issue The Chemistry of Sustainable Energy Conversion and Storage)

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12 pages, 3207 KiB

Open AccessArticle

In-Situ Synthesis of Heterostructured Carbon-Coated Co/MnO Nanowire Arrays for High-Performance Anodes in Asymmetric Supercapacitors

by Guoqing Chen, Xuming Zhang, Yuanhang Ma, Hao Song, Chaoran Pi, Yang Zheng, Biao Gao, Jijiang Fu and Paul K. Chu

Molecules 2020, 25(14), 3218; https://doi.org/10.3390/molecules25143218 - 15 Jul 2020

Cited by 10 | Viewed by 2803

Abstract

Structural design is often investigated to decrease the electron transfer depletion in/on the pseudocapacitive electrode for excellent capacitance performance. However, a simple way to improve the internal and external electron transfer efficiency is still challenging. In this work, we prepared a novel structure [...] Read more.

Structural design is often investigated to decrease the electron transfer depletion in/on the pseudocapacitive electrode for excellent capacitance performance. However, a simple way to improve the internal and external electron transfer efficiency is still challenging. In this work, we prepared a novel structure composed of cobalt (Co) nanoparticles (NPs) embedded MnO nanowires (NWs) with an N-doped carbon (NC) coating on carbon cloth (CC) by in situ thermal treatment of polydopamine (PDA) coated MnCo₂O_4.5 NWs in an inert atmosphere. The PDA coating was carbonized into the NC shell and simultaneously reduced the MnCo₂O_4.5 to Co NPs and MnO NWs, which greatly improve the surface and internal electron transfer ability on/in MnO boding well supercapacitive properties. The hybrid electrode shows a high specific capacitance of 747 F g⁻¹ at 1 A g⁻¹ and good cycling stability with 93% capacitance retention after 5,000 cycles at 10 A g⁻¹. By coupling with vanadium nitride with an N-doped carbon coating (VN@NC) negative electrode, the asymmetric supercapacitor delivers a high energy density of 48.15 Wh kg⁻¹ for a power density of 0.96 kW kg⁻¹ as well as outstanding cycling performance with 82% retention after 2000 cycles at 10 A g⁻¹. The electrode design and synthesis suggests large potential in the production of high-performance energy storage devices. Full article

(This article belongs to the Special Issue The Chemistry of Sustainable Energy Conversion and Storage)

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Review

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20 pages, 4432 KiB

Open AccessReview

Implementation of Bismuth Chalcogenides as an Efficient Anode: A Journey from Conventional Liquid Electrolyte to an All-Solid-State Li-Ion Battery

by Rini Singh, Pooja Kumari, Manoj Kumar, Takayuki Ichikawa and Ankur Jain

Molecules 2020, 25(16), 3733; https://doi.org/10.3390/molecules25163733 - 15 Aug 2020

Cited by 22 | Viewed by 4605

Abstract

Bismuth chalcogenide (Bi₂X₃; X = sulfur (S), selenium (Se), and tellurium (Te)) materials are considered as promising materials for diverse applications due to their unique properties. Their narrow bandgap, good thermal conductivity, and environmental friendliness make them suitable candidates [...] Read more.

Bismuth chalcogenide (Bi₂X₃; X = sulfur (S), selenium (Se), and tellurium (Te)) materials are considered as promising materials for diverse applications due to their unique properties. Their narrow bandgap, good thermal conductivity, and environmental friendliness make them suitable candidates for thermoelectric applications, photodetector, sensors along with a wide array of energy storage applications. More specifically, their unique layered structure allows them to intercalate Li⁺ ions and further provide conducting channels for transport. This property makes these suitable anodes for Li-ion batteries. However, low conductivity and high-volume expansion cause the poor electrochemical cyclability, thus creating a bottleneck to the implementation of these for practical use. Tremendous endeavors have been devoted towards the enhancement of cyclability of these materials, including nanostructuring and the incorporation of a carbon framework matrix to immobilize the nanostructures to prevent agglomeration. Apart from all these techniques to improve the anode properties of Bi₂X₃ materials, a step towards all-solid-state lithium-ion batteries using Bi₂X₃-based anodes has also been proven as a key approach for next-generation batteries. This review article highlights the main issues and recent advances associated with Bi₂X₃ anodes using both solid and liquid electrolytes. Full article

(This article belongs to the Special Issue The Chemistry of Sustainable Energy Conversion and Storage)

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