Application Of Energy Technologies Research Articles

A lignin–derived N-doped carbon-supported iron-based nanocomposite as high-efficiency oxygen reduction reaction electrocatalyst

Fuel cells are a promising renewable energy technology that depend heavily on noble metal Pt-based catalysts, particularly for the oxygen reduction reaction (ORR). The discovery of new, efficient non-precious metal ORR catalysts is critical for the continued development of cost-effective, high-performance fuel cells. The synthesized carbon material showed excellent electrocatalytic activity for the ORR, with half-wave potential (E1/2) and limiting current density (JL) of 0.88 V and 5.10 mA·cm−2 in alkaline electrolyte, respectively. The material has a Tafel slope of (65 mV dec−1), which is close to commercial Pt/C catalysts (60 mV dec−1). Moreover, the prepared materials exhibited excellent performance when assembled as cathodes for zinc-air batteries. The power density reached 110.02 mW cm−2 and the theoretical specific capacity was 801.21 mAh g−1, which was higher than that of the Pt/C catalyst (751.19 mAh g−1). In this study, with the assistance of Mg5(CO3)4(OH)2·4H2O, we introduce an innovative approach to synthesize advanced carbon materials, achieving precise control over the material's structure and properties. This research bridges a crucial gap in material science, with potential applications in renewable energy technologies, particularly in enhancing catalysts for fuel cells.

Innovative Morphology Control Method: Modulating Metal Ratios in NixCoP@NF for Hydrogen Evolution Reaction

AbstractThe use of non‐precious metal materials for catalyzing the hydrogen evolution reaction (HER) holds significant importance for the widespread application of new energy technologies. In this study, we prepare a novel foam nickel (NF) supported NixCoP (NixCoP@NF) nanocrystal through a one‐pot hydrothermal method and high‐temperature phosphorization, involving a straightforward process. Innovatively, we achieve morphology control of NixCoP@NF by altering the Ni : Co ratio to maximize its active surface area. The resulting ′petal‐like′ Ni0.5CoP@NF nanostructure exhibits high activity and long‐term durability in an alkaline medium (1 M KOH), with an overpotential of 58 mV at a current density of 10 mA ⋅ cm−2, a Tafel slope of 60.82 mV ⋅ dec−1, and demonstrates lower impedance compared to most non‐precious metal HER electrocatalysts. Furthermore, the variation in activation energy (Ea) reflects the thermodynamic advantages during the electrolysis process. This work offers a new approach for the development of simple and cost‐effective HER catalysts.

A dense station-based, long-term and high-accuracy dataset of daily surface solar radiation in China

Abstract. The lack of long-term and high-quality solar radiation data has been an obstacle for scientific and industrial fields. In this study, a dense station-based, long-term and high-accuracy dataset of daily surface solar radiation was developed using two surface radiation models. One is the model developed by Yang et al. (2006) for global radiation estimation, and the other is the model developed by Tang et al. (2018) for direct radiation estimation. The main inputs for the development of the dataset are surface pressure, air temperature, relative humidity, horizontal visibility and sunshine duration, which are the routine meteorological variables observed at the 2743 China Meteorological Administration (CMA) weather stations. Validation against in situ observations and comparisons with two satellite-based radiation products shows that our station-based radiation dataset clearly outperforms the satellite-based radiation products at both daily and monthly scales. In addition, our dataset is available for more than 60 years and includes three radiation components of global, direct and diffuse radiation, which is not possible with satellite products. This station-based radiation dataset will contribute to the climate change research and solar energy engineering applications in the future. The station-based dataset is now available at https://doi.org/10.11888/Atmos.tpdc.300461 (Tang, 2023).

Growth and Local Structures of Single Crystalline Flakes of Three-Dimensional Covalent Organic Frameworks in Water.

Due to the enormous chemical and structural diversities and designable properties and functionalities, covalent organic frameworks (COFs) hold great promise as tailored materials for industrial applications in electronics, biology, and energy technologies. They were typically obtained as partially crystalline materials, although a few single-crystal three-dimensional (3D) COFs have been obtained recently with structures probed by diffraction techniques. However, it remains challenging to grow single-crystal COFs with controlled morphology and to elucidate the local structures of 3D COFs, imposing severe limitations on the applications and understanding of the local structure-property correlations. Herein, we develop a method for designed growth of five types of single crystalline flakes of 3D COFs with controlled morphology, front crystal facets, and defined edge structures as well as surface chemistry using surfactants that can be self-assembled into layered structures to confine crystal growth in water. The flakes enable direct observation of local structures including monomer units, pore structure, edge structure, grain boundary, and lattice distortion of 3D COFs as well as gradually curved surfaces in kinked but single crystalline 3D COFs with a resolution of up to ∼1.7 Å. In comparison with flakes of two-dimensional crystals, the synthesized flakes show much higher chemical, mechanical, and thermal stability.

Integrating Renewable-Based Solar Energy into Sustainable and Resilient Urban Furniture Coupled with a Logical Multi-Comparison Study of Cyprus and Saudi Arabia

The purpose of this research is to analyze and evaluate the urban furniture in the public space of Dr. Fazil Kucuk Park in Nicosia and compare it with a logical Saudi Arabian case study. As such, the focus is on sustainability and renewable energy sources, especially the application of solar energy technologies in urban furniture, in order to determine the feasibility of using sustainable energy to operate the park. A qualitative research approach was chosen, using both secondary and primary data, along with images from the park. The data were analyzed using descriptive analysis, and this applies to both primary and secondary data used in this study. This research used six types of urban furniture, which are lighting, public art, benches, trash cans, bike stands, and billboards. The study showed that only the lights are efficient in using solar energy in the garden, while the rest of the furniture does not have it. The study assesses the integration of solar energy technologies in urban furniture at Dr. Fazil Kucuk Park in Nicosia, contrasting it with a Saudi Arabian case. The study’s scope encompasses six urban furniture types, emphasizing sustainability. The findings suggest actionable insights for enhancing furniture to align with international sustainable development standards. Therefore, it was concluded that more efforts are needed to upgrade the urban furniture in Dr. Fazil Kucuk Park to meet international standards to achieve sustainable development.

Atom Bound Connectivity, Zagreb, Sombor, Nirmala and Harmonic Indices of Dendrimers

A nanostar is a very small molecule ranging in size from 1-100 nanometers. It is typically composed of materials such as polymers, silica and others. Nanostars are of great significance in various fields, including drug technology, energy technology and other applications. The topological index is a numerical depiction of a molecular structure. Within chemical graphs, the atoms and the chemical bonds connecting them are symbolized by vertices and edges, respectively. Topological indices help to predict the topological properties of nanostar dendrimers, such as molecular weight and size. In this article, we computed the first Zagreb index, the second Zagreb Index, the third Zagreb index, Sombor index, ABC index, Nirmala index and Harmonic index of two new families of nanostar dendrimers such as is also known as aminoisophthalate diester monomer and known as Poly (amidoamine).

Mechanisms of Biomolecular Self‐Assembly Investigated Through In Situ Observations of Structures and Dynamics

AbstractBiomolecular self‐assembly of hierarchical materials is a precise and adaptable bottom‐up approach to synthesizing across scales with considerable energy, health, environment, sustainability, and information technology applications. To achieve desired functions in biomaterials, it is essential to directly observe assembly dynamics and structural evolutions that reflect the underlying energy landscape and the assembly mechanism. This review will summarize the current understanding of biomolecular assembly mechanisms based on in situ characterization and discuss the broader significance and achievements of newly gained insights. In addition, we will also introduce how emerging deep learning/machine learning‐based approaches, multiparametric characterization, and high‐throughput methods can boost the development of biomolecular self‐assembly. The objective of this review is to accelerate the development of in situ characterization approaches for biomolecular self‐assembly and to inspire the next generation of biomimetic materials.

Mechanisms of Biomolecular Self-Assembly Investigated Through In Situ Observations of Structures and Dynamics.

Biomolecular self-assembly of hierarchical materials is a precise and adaptable bottom-up approach to synthesizing across scales with considerable energy, health, environment, sustainability, and information technology applications. To achieve desired functions in biomaterials, it is essential to directly observe assembly dynamics and structural evolutions that reflect the underlying energy landscape and the assembly mechanism. This review will summarize the current understanding of biomolecular assembly mechanisms based on in situ characterization and discuss the broader significance and achievements of newly gained insights. In addition, we will also introduce how emerging deep learning/machine learning-based approaches, multiparametric characterization, and high-throughput methods can boost the development of biomolecular self-assembly. The objective of this review is to accelerate the development of in situ characterization approaches for biomolecular self-assembly and to inspire the next generation of biomimetic materials.

Enhancing the performance of water-based PVT collectors with nano-PCM and twisted absorber tubes

The study investigated the thermal performance of a photovoltaic thermal (PVT) collector with a twisted absorber tube and nanoparticle-enhanced phase change material (nano-PCM). The PVT collector consisted of twisted absorber tubes, a container filled with nano-PCM, and a photovoltaic (PV) panel. To assess its efficiency, five different configurations were tested using an indoor solar simulator. The configurations analyzed were as follows: (a) an unenhanced PV panel, (b) PVT with circular absorber tubes (C-PVT), (c) PVT with twisted absorber tubes (T-PVT), (d) C-PVT with nano-PCM (C-PVT-PCM), and (e) T-PVT with nano-PCM (T-PVT-PCM). The thermal, photovoltaic, and combined photovoltaic-thermal efficiencies were evaluated at varying mass flow rates (0.008-0.04kg/s) and a constant solar irradiance of 800W/m2. Among the configurations tested, the T-PVT-PCM configuration demonstrated the highest performance. Specifically, at a mass flow rate of 0.04kg/s, solar irradiance of 800W/m2, and an ambient temperature of 27°C, it achieved photovoltaic, thermal, and combined photovoltaic-thermal efficiencies of 9.46%, 79.40%, and 88.86%, respectively. The utilization of twisted absorber tubes in the design notably improved thermal efficiency by enhancing heat transmission between the liquid and the tube surface. Furthermore, the implementation of T-PVT-PCM led to a significant reduction in surface temperature. Compared to the unenhanced PV panel, it lowered the surface temperature by approximately 30°C, and when compared to C-PVT-PCM, it reduced it by around 10°C. Notably, T-PVT-PCM outperformed the unenhanced PV panel by exhibiting a 34.5% higher photovoltaic efficiency. Overall, the study highlights the performance of the PVT collector with twisted absorber tubes and nanoparticle-enhanced phase change material. The innovative design achieved remarkable thermal efficiency, reduced surface temperatures, and significantly enhanced photovoltaic efficiency compared to traditional configurations. These findings contribute to the development of more efficient and versatile solar energy systems with the potential for broader applications in renewable energy technology.

Towards the application of renewable energy technologies in green ports: Technical and economic perspectives

AbstractWith growing concerns over environmental degradation and climate change, the shipping industry is under increasing pressure to reduce its environmental impact. This has led to the development of green port initiatives in the field of maritime transport and logistics, which aim to promote sustainable practices and reduce the environmental footprint of ports and their operations. One of the key strategies for achieving this goal is the use of renewable energy technologies (RETs). This paper summarizes the potentials, challenges, and economic analysis of RETs applications in green ports, emphasizing those that require aquatic environments for operation, including floating photovoltaic systems, offshore wind turbines, and ocean energy. The paper investigates the concept of green ports and explores the feasibility of integrating RETs into these facilities. Also, the potential of the various RETs is presented in terms of technical and economic aspects and installed capacity. Additionally, due to high flexibility in electrical systems and compatibility with maritime transportation, the use of fuel cells in green ports has been discussed as a feasible solution for supplying power to ports (either as the primary or backup source). The findings of this study show that RETs can significantly contribute to achieving sustainable goals in the maritime industry and pave the way for the creation of more efficient and environmentally friendly ports.

Application scenario evaluation of modified converter for quadratic Boost high gain DC-DC: taking the constant off time control mode as an example

Abstract In recent years, due to the energy crisis and serious environmental problems, the use and development of new energy has become the focus of research. Therefore, the application of new energy technologies has increased the demand for direct current to direct current (DC-DC) converters. The improvement of converter capability effectively enhances the functions of DC-DC converters, which makes it easy for secondary converters to meet the requirements of voltage gain, and expands the input voltage range of DC-DC converters, thereby having a good prospect in new energy applications. However, due to the many drawbacks of the quadratic Boost converter, such as pressure rise limitation, high switching stress, in order to reduce the working pressure of the improved quadratic Boost high gain converter and improve its operating performance, it is necessary to optimize it. Based on the application scenario of an modified converter for quadratic Boost high gain DC-DC, and taking the constant off time control method as an example, this paper conducted research to accurately recognize the current status of the converter and improve the utilization efficiency of the converter. In this paper, four groups of traditional converters and two types of improved quadratic Boost high gain DC-DC converters were selected as experimental objects for comparative analysis of images and data. The results showed that the conversion efficiency of the constant off time control method in the modified DC-DC converter based on quadratic high gain was 7.03 % higher than that of the traditional converter, while also improving the conversion efficiency of voltage gain and reducing switching stress, with higher safety. This indicated that the improved DC-DC converter with secondary high gain has better effects and wider application scenarios, thereby better serving new energy systems.

Gamma radiation shielding simulation for thermoplastic elastomer and silicon rubber/alloy dopant with functional nanoparticle

With the global energy crisis worsening, the research and application of new energy have become a strategic objective for the major countries’ long-term development in the twenty-first century. Nuclear energy technology development and application have become central to new energy development. Numerous types of high-energy radiation (such as X-rays, gamma rays, and neutron rays) produced by nuclear materials not only impose stricter requirements on the radiation-resistant materials used in the reactor but also risk causing significant environmental pollution (nuclear pollution) and serious harm to human life and health if a leak does not form. As a result, the prudent control and protection of nuclear radiation have become critical issues in the development of nuclear energy. With the rapid development of nuclear power today, it is necessary to seek new nuclear radiation protection materials, particularly those with high energy, penetrating ability, and other neutron-protective material characteristics. This is a new type of nuclear power design and construction of critical materials. In this study, WinXCom software is used to simulate the shielding properties of the used functional shielding element, compounds of metal oxide, and the mixture of RTV and TPE with the functional nanoparticle and observe the K-edge absorption of the material used. Based on the simulation, the shielding performance of the selected element of Sm was observed to have the smallest weak gap absorption zone of 40-47 MeV in common medical radiation of 30-150 KeV. Different sets of combinations of shielding material were simulated and found that the combination of WO3 with Sm2O3 gave the most pronounced radiation shielding performance with two strong absorption peaks at 46.8 KeV and 69.5 KeV. RTV composite (Sm2O3+RTV+ WO3) with WO3 as matrix gave the best shielding performance and was used as a reference for the manufacture of the new type of shielding materials.

Optimal pathway to urban carbon neutrality based on scenario simulation: A case study of Shanghai, China

Scientific analysis and prediction of carbon-neutral pathways can help rationalise the advancement of carbon neutrality goals, but how to apply simulation scenario system modelling to analyse the optimal pathways to achieve carbon neutrality in cities needs further research. By constructing the Low Emissions Analysis Platform (LEAP)-Shanghai model and simulating different future policy scenarios based on policy costs and carbon emission constraints, this work proposes an optimal path to achieve carbon neutrality, providing a new perspective for city-level carbon neutrality research. The results show that energy intensity policies and energy structure transformation policies have a significant impact on achieving carbon neutrality, with a synergistic effect when the two policies are combined. Carbon sink policies coupled with energy intensity and energy structure transformation policies also play a significant role. Various policy combinations could lead to a carbon-neutral Shanghai by 2060, with the optimal scenario being a 3.5% average annual reduction in energy intensity and a 6.5% average annual reduction in carbon emissions per unit of energy consumption. The key to achieving carbon neutrality lies in the rapid transition of the tertiary sector, promoting the advancement and application of clean energy technologies, advancing the transformation of nonelectric energy sources to electric energy sources, and promoting biomass energy and carbon capture and storage (CCS) technologies.

Rechargeable Na-MnO2 battery with modified cell chemistry

High voltage, high energy density, nominal cycle life, and low cost are the most critical requirements of rechargeable batteries for their widespread energy storage applications in electric vehicles and renewable energy technologies. Na-MnO2 battery could be a low-cost contender, but it suffers extensively from its low cell voltage and poor rechargeability. In this study, we modified the conventional cell structure of Na-MnO2 battery and established altered cell chemistry through a hybrid electrochemical process consisting of Na striping/plating at the anode and Zn2+ insertion/de-insertion along with MnO2 dissolution/deposition at the cathode. After the modification, Na-MnO2 battery exhibits a discharge capacity of 267.10 mA h/g and a cell voltage of 3.30 V (vs. Na/Na+), resulting in a high specific energy density of 881.43 Wh/kg. After 300 cycles, the battery retains 98% of its first-cycle discharge capacity with 100% coulombic efficiency. Besides, Na metal-free battery assembled using sodium biphenyl as a safer anode also delivers an excellent energy density of 810.0 Wh/kg. This work could provide a feasible method to develop an advanced Na-MnO2 battery for real-time energy storage applications.

Evolution of nanopores in hexagonal boron nitride

The engineering of atomically-precise nanopores in two-dimensional materials presents exciting opportunities for both fundamental science studies as well as applications in energy, DNA sequencing, and quantum information technologies. The exceptional chemical and thermal stability of hexagonal boron nitride (h-BN) suggest that exposed h-BN nanopores will retain their atomic structure even when subjected to extended periods of time in gas or liquid environments. Here we employ transmission electron microscopy to examine the time evolution of h-BN nanopores in vacuum and in air and find, even at room temperature, dramatic geometry changes due to atom motion and edge contamination adsorption, for timescales ranging from one hour to one week. The discovery of nanopore evolution contrasts with general expectations and has profound implications for nanopore applications of two-dimensional materials.

Energy saving in industrial buildings using advanced concentrated solar thermal systems

Saving energy in industrial buildings is one of the ten pillars of the European Green Deal. The application of renewable energy technologies in industrial processes and their buildings is an appropriate way to support the European energy goals. The paper presents an innovative solar heating method for industrial buildings that focuses on overcoming the current limitations of these systems. The method is based on the modular and flexible integration of two innovative technologies for the solar collector (SunDial technology – parabolic collectors) and thermal energy storage (based on phase change materials, PCM) which, through a control system, allow flexible operation to maintain continuous use against the unpredictable nature of the solar source and partly even during the night. The method can cover a significant percentage of the heat demand in industrial processes that use temperatures above 150°C. At the same time, there is the possibility of meeting cooling needs using an absorption chiller.The work describes the technologies of centralized solar collectors and the connection, operation, control and monitoring systems as well as the possibilities of covering thermal and cooling loads in an industrial building. This technology can be applied to both commercial and residential buildings. The purpose of this application is to contribute to the reduction of the requirements for heating and cooling in industrial buildings of the European Union which is estimated at approximately 72TWh per year.

Simulation of Turbulent Flow Structure and Particle Deposition in a Three-Dimensional Heat Transfer Duct with Convex Dimples

In engineering applications, dust deposition on the heat transfer channel greatly reduces the efficiency of heat transfer. Therefore, it is very significant to study the characteristics of particle deposition for thermal energy engineering applications. In this study, the Reynolds stress model (RSM) and the discrete phrase model (DPM) were used to simulate particle deposition in a 3D convex-dimpled rough channel. A discrete random walk model (DRW) was used for the turbulent diffusion of particles, and user-defined functions were developed for collisions between particles and walls. An improved deposition model of rebound between particles was developed. The flow structure, secondary flow, temperature distribution, Q criterion, and particle deposition distribution in the convex-dimpled rough channel were analyzed after a study of the grid independence and a numerical validation. The results showed that these mechanisms affected the flow structure in the flow field. For tiny particles (dp ≤ 10 μm), the presence of convex dimples promoted their deposition. The rates of particle deposition in the presence of convex dimples were 535, 768, 269, and 2 times higher than in smooth channels (particle sizes of 1, 3, 5, and 10 μm, respectively). However, for large particles (dp > 10 μm), although the presence of convex dimples had a certain effect on the location distribution of particle deposition, it had little effect on the deposition rates of large particles, which were 0.99, 0.98, 0.97 and 0.96 times those in the smooth channel, respectively.

The Role of Electron–Electron Interaction in Charge Transport Calculations through Transition Metal Dichalcogenides Heterojunctions

2D materials have raised a lot of interest in the last decades, due to their novel and diverse properties, particularly for energy technology applications where materials such as molybdenum disulfide are known for their outstanding catalytic ability. While intensive research is devoted to 2D transition metal dichalcogenide (TMDCs) semiconductor characterization, comprehensive understanding of metal/semiconductor heterojunctions is still lacking especially for junctions containing 2D metallic monolayers other than graphene. Using wave‐packet propagation, charge transport of two electrons through heterojunctions is simulated, in order to assess the influence of the electron–electron interaction on the charge transport efficiency. TMDCs with similar structure for both metal and semiconductor monolayers are used, leading to a high‐quality metal contact. It is found that charge transport is more efficient in systems containing a chromium disulfide semiconductor monolayer compared to systems with MoS2 or tungsten disulfide. This trend in the efficiency is the same with and without electron–electron interaction, demonstrating the validity of the qualitative input provided by models that lack electron–electron interactions. Nevertheless, for all systems, the interaction increases charge transmission probability from the metal to the semiconductor, due to electronic repulsion that pushes one of the charge carriers forward across the interface.

Tungsten suboxide (WO3−x) petal-like nanosheets created by laser ablation method

As a promising candidate in two-dimensional transition metal dichalcogenide (2D TMD), tungsten suboxide (WO[Formula: see text]) nanostructures are synthesized using pulsed laser ablation in liquid. The WO[Formula: see text] petal-like nanosheets were obtained by irradiating bulk WS2 in ethanol and distilled water using nanosecond (ns) laser ablation with the help of the second harmonic Nd:YAG laser. The synthesized WO[Formula: see text] petal-like nanosheets with uniform length up to 20 nm as per surface morphology were observed using field emission scanning electron microscopy (FESEM). The further characterization of the synthesized material was performed using UV-spectroscopy, energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD) spectroscopy, and Raman spectroscopy. EDS spectrum clearly suggests the formation of WO[Formula: see text]. This research on the findings of WO[Formula: see text] forecasts for the possible use of transition metal oxides-based nanostructures for numerous applications in optoelectronics and energy technologies.

Construction of 3D Hierarchical Co3O4@CoFe-LDH Heterostructures with Effective Interfacial Charge Redistribution for Rechargeable Liquid/Solid Zn-Air Batteries.

Constructing three-dimensional (3D) hierarchical heterostructures is an appealing but challenging strategy to improve the performance of catalysts for electrical energy devices. Here, an efficient and robust flexible self-supporting catalyst, interface coupling of ultrathin CoFe-LDH nanosheets and Co3O4 nanowire arrays on the carbon cloth (CC/Co3O4@CoFe-LDH), was proposed for boosting oxygen evolution reaction (OER) in rechargeable liquid/solid Zn-air batteries (ZABs). The strong interfacial interaction between the CoFe-LDH and Co3O4 heterostructures stimulated the charge redistribution in their coupling regions, which improved the electron conductivity and optimized the adsorption free energy of OER intermediates, ultimately boosting the intrinsic OER performance. Besides, the 3D hierarchical nanoarray structure facilitated the exposure of catalytically active centers and rapid electron/mass transfer during the OER process. As such, the CC/Co3O4@CoFe-LDH catalyst achieved excellent OER catalytic activity in alkaline medium, with a small overpotential of 237 mV at 10 mA cm-2, a low Tafel slope of 35.43 mV dec-1, and long-term durability of up to 48 h, significantly outperforming the commercial RuO2 catalyst. More impressively, the liquid and flexible solid-state ZABs assembled by the CC/Co3O4@CoFe-LDH hybrid catalyst as the OER catalyst presented a stable open circuit voltage, large power density, superb cycling life, and satisfactory flexibility, indicating great potential applications in energy technology. This work provides a good guidance for the development of advanced electrocatalysts with heterostructures and an in-depth understanding of electronic modulation at the heterogeneous interface.