Sustainable Energy Conversion Systems Research Articles

Symmetric Catalyst Design Employing Ir Nanoparticles on Black WO3- x Nanofiber Support for Boosting Water Electrolysis.

The efficient evolution of gaseous hydrogen and oxygen from water is required to realize sustainable energy conversion systems. To address the sluggish kinetics of the multielectron transfer reaction, bifunctional catalyst materials for both the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER) should be developed. Herein, a tailored combination of atomically minimized iridium catalysts and highly conductive black WO3- x nanofiber supports are developed for the bifunctional electrolyzer system. Atomic Ir catalysts, particularly those that activate the OER, minimize the utilization of precious metals. The oxygen-deficient black WO3- x NF support, which boosts the HER, offers increased electronic conductivity and favorable nucleation sites for Ir loading. The Ir-black WO3- x NFs exhibit increased double-layer capacitance, a significantly reduced onset potential, lower Tafel slope, and stable cyclability for both the OER and HER, compared to large-sized Ir catalysts loaded on white WO3 nanofibers. This study offers a strategy for developing an optimal catalyst material with suitable supports for high-performance and economical water electrolysis systems for achieving carbon-negative targets.

Nanostructured Materials for Enhanced Performance of Solid Oxide Fuel Cells: A Comprehensive Review

Solid oxide fuel cells (SOFCs) have emerged as promising candidates for efficient and environmentally friendly energy conversion technologies. Their high energy conversion efficiency and fuel flexibility make them particularly attractive for various applications, ranging from stationary power generation to portable electronic devices. Recently, research has focused on utilizing nanostructured materials to enhance the performance of SOFCs. This comprehensive review summarizes the latest advancements in the design, fabrication, and characterization of nanostructured materials integrated in SOFC. The review begins by elucidating the fundamental principles underlying SOFC operation, emphasizing the critical role of electrode materials, electrolytes, and interfacial interactions in overall cell performance, and the importance of nanostructured materials in addressing key challenges. It provides an in-depth analysis of various types of nanostructures, highlighting their roles in improving the electrochemical performance, stability, and durability of SOFCs. Furthermore, this review delves into the fabrication techniques that enable precise control over nanostructure morphology, composition, and architecture. The influence of nanoscale effects on ionic and electronic transport within the electrolyte and electrodes is thoroughly explored, shedding light on the mechanisms behind enhanced performance. By providing a comprehensive overview of the current state of research on nanostructured materials for SOFCs, this review aims to guide researchers, engineers, and policymakers toward the development of high-performance, cost-effective, and sustainable energy conversion systems.

An Innovative Tubular Thermoelectric Generator (TTEG) for Enhanced Waste Heat Recovery in Industrial and Automotive Applications

In response to the growing need for efficient energy conversion technologies, this paper introduces an innovative Tubular Thermoelectric Generator (TTEG), specifically designed for the high-efficiency conversion of waste heat into electrical energy. Unlike conventional flat-plate thermoelectric generators (FTEGs), the TTEG incorporates full-ring thermoelectric elements within a tubular layout, offering a novel approach to thermal energy recovery from fluid-based systems. This design significantly enhances the heat transfer capabilities, thereby improving the efficiency of energy conversion. Moreover, it is optimally tailored for integration into any cylindrical pipe to recapture and repurpose waste heat. Comprehensive simulations and analyses form the core of this study, where the performance of the TTEG is rigorously compared with traditional FTEGs. Under identical conditions of heat exposure, volume, and properties of thermoelectric materials, the TTEG demonstrates a 62.5% increase in output power compared to the TGM1-127-1.0-0.8 thermoelectric module (FTEG). These comparisons highlight the advantages of the tubular design in terms of energy conversion efficiency and practical applicability in various scenarios. The findings reveal that the TTEG not only outperforms its flat-plate counterparts but also presents a scalable and adaptable solution for waste heat recovery in a wide range of industrial and automotive applications. This research contributes to the field of energy science and technology by presenting a detailed experimental setup, complete with reproducible procedures and results. It opens new pathways for the development of more sustainable and efficient energy conversion systems, aligning with the goal of harnessing renewable and sustainable energy sources. The potential applications of this technology in enhancing energy efficiency and reducing environmental impact are vast, making it a significant step forward in the quest for clean and sustainable energy solutions.

Electrospun Polymer Supported Cux O Nanostructures for CO2 Reduction Reaction

The reduction of carbon dioxide (CO2) to value-added products is a promising approach for mitigating the impact of CO2 emissions on the environment [1]. Copper oxide (CuO) and copper oxide (Cu2O) have been identified as effective catalysts for CO2 reduction reaction (CO2RR) due to their unique electronic properties [2]. Electrospinning is a versatile and efficient technique for the fabrication of high surface area polymer (P) nanofibers which enables a promising range of applications in energy storage and conversion [3].In this study, we investigate the synthesis of CuxO-incorporated polyacrylonitrile (PAN) and PAN/polyaniline (PANI) nanofibers via electrospinning and evaluate their performance as a catalyst for CO2RR. The CuxO/P nanofibers were characterized by various techniques such as scanning electron microscopy (SEM), X-ray diffraction (XRD) and Fourier-transform infrared (FTIR) spectroscopy.The results revealed that CuxO nanoparticles were dispersed on the surface of the polymer nanofibers. The XRD analysis confirmed the presence of crystalline CuxO nanoparticles in the nanofibers. The FTIR spectra indicated that CuxO was successfully incorporated into the polymer nanofibers without new chemical bond formation between CuxO and PAN.The catalytic performance of CuxO/P nanofibers was evaluated for CO2RR in a three-electrode electrochemical cell. The CuxO/P nanofibers showed a significantly enhanced catalytic activity for CO2RR. Moreover, the CuxO/P nanofibers showed good stability during the electrochemical CO2RR.The enhanced catalytic performance of CuxO/P nanofibers can be attributed to the unique electronic properties of CuxO nanoparticles, which can facilitate the adsorption and activation of CO2 molecules. Furthermore, the high surface area and porous structure of the polymer nanofibers provide abundant active sites for the CO2RR. The dispersion of CuxO nanoparticles on the surface of the polymer nanofibers can also enhance electron transfer and reduce charge transfer resistance during the CO2RR.In conclusion, CuxO-incorporated polymer nanofibers were successfully synthesized by electrospinning and showed excellent catalytic activity for CO2RR. The CuxO/P nanofibers exhibited high selectivity and stability for the electrochemical reduction of CO2 to useful chemicals. These findings suggest that CuxO/P nanofibers have great potential as an efficient catalyst for CO2RR and could contribute to the development of sustainable energy conversion and storage systems.[1] A. Aljabour, D. H. Apaydin, H. Coskun, F. Ozel, M. Ersoz, P. Stadler, N. S. Sariciftci, and M. Kus, ACS Applied Materials & Interfaces, 8 (46), 31695-31701 (2016).[2] R. W. Abebe, H. Zanling, Z. Pengxiang, H. Liangsheng, A. Didier, Coordination Chemistry Reviews, 454, 214340 (2022).[3] A. Aljabour, ChemistrySelect 5, 7482 (2020). Figure 1

Optimizing Induction Wind Energy System with EDLC and PMSG for Efficient Power Control

This paper represents a comprehensive study on the optimization of an Induction Wind Energy System (IWEC) integrated with Electric Double Layer Capacitors (EDLCs) and a Permanent Magnet Synchronous Generator (PMSG) to enhance power control in the quest for sustainable and efficient energy conversion systems. As wind energy plays a pivotal role in the renewable energy landscape, maximizing its conversion efficiency is crucial for a sustainable future. Advanced control strategies and optimization techniques are applied to delve into the intricate details of the IWEC-EDLC-PMSG system, resulting in improved power quality, enhanced transient response, and superior grid integration capabilities. The research demonstrates that this integrated configuration outperforms conventional wind energy systems in terms of efficiency, grid compatibility, and dynamic response. Moreover, the study addresses key aspects like system stability, fault tolerance, and reliability, ensuring the robustness of this innovative solution. In addition to advancing wind energy technology, this research offers valuable insights into integrating energy storage systems and advanced control techniques for efficient power control in renewable energy applications, contributing to a sustainable energy future.

Optimization Design and Simulation Approach of an Axial Inward Flow Reaction Turbine Incorporating with Organic Rankine Cycle

The demand for sustainable and efficient energy conversion systems has led to the exploration of various turbines design and working fluids. This study focuses on the design and simulation investigation of an axial inward flow reaction turbine utilizing organic fluids as the working medium. Organic fluids have gained attention due to their favourable themodynamic properties and low environmental impact. The selection process for the working fluid takes into consideration factors such as temperature limitations fluids availability and efficiency. The design process begins with a thorough analysis of the fundamental principles govering inward flow reaction turbines. Fluids flow path, blade profiles, the interaction between the fluid and these blades are carefully studied. Design parameters such as specific spedd, specific diameter and specific speed coefficient are determind to ensure optimal turbine performance

3D numerical analysis of a photovoltaic thermal using bi-fluid: Al2O3–water nanofluid at various concentrations

This study aims to use a cooling technology for photovoltaic-thermal (PVT) collectors more effective in terms of cooling and enhancing the thermal efficiency of the system in general. This was done by using bi-fluid modes (air and Al2O3–water nanofluid), which are characterized by being more effective in terms of cooling and enhancing the overall thermal efficiency of the system. To achieve this, aluminum dual exchangers were incorporated with an aluminum back surface of the monocrystalline photovoltaic panels. The cooling was achieved using the Al2O3–water nanofluid at various concentrations of 0.0, 0.2, 0.4, 0.6, 0.8, and 1 % with a steady flow of water at 0.01 kg/s and at a simultaneous airflow rate. Also, the effect of different levels of Al2O3 nanoparticle concentrations (0.0, 0.2, 0.4, 0.6, 0.8, and 1 %) was studied to identify the optimal concentration of Al2O3–water nanofluids that achieves the highest rates of cooling and thermal efficiency of PVT collectors. The 3D numerical model was validated using the experimental published data. The results showed that the total thermal efficiency of PVT modules with the bi-fluid modes is equal to 46.63 %, 48.96 %, 52.39 %, 54.13 %, 59.43 %, and 63.28 %, for Al2O3–water nanofluids concentrations of 0.0, 0.2, 0.4, 0.6, 0.8, and 1 %, respectively. The PV module with the bi-fluid modes (air and Al2O3–water nanofluids with 1 % concentration) at a steady flow of water at 0.01 kg/s is the best design for effective cooling of PV panels, which can contribute to more sustainable and energy-efficient solar energy conversion systems.

Phytic acid-derivative Co2B-CoPOx coralloidal structure with delicate boron vacancy for enhanced hydrogen generation from sodium borohydride

Application of transition metal boride (TMB) catalysts towards hydrolysis of NaBH4 holds great significance to help relieve the energy crisis. Herein, we present a facile and versatile metal-organic framework (MOF) assisted strategy to prepare Co2B-CoPOx with massive boron vacancies by introducing phytic acid (PA) cross-linked Co complexes that are acquired from reaction of PA and ZIF-67 into cobalt boride. The PA etching effectively breaks down the structure of ZIF-67 to create more vacancies, favoring the maximal exposure of active sites and elevation of catalytic activity. Experimental results demonstrate a drastic electronic interaction between Co and the dopant phosphorous (P), thereby the robustly electronegative P induces electron redistribution around the metal species, which facilitates the dissociation of B-H bond and the adsorption of H2O molecules. The vacancy-rich Co2B-CoPOx catalyst exhibits scalable performance, characterized by a high hydrogen generation rate (HGR) of 7716.7 mL min−1 g−1 and a low activation energy (Ea) of 44.9 kJ/mol, rivaling state-of-the-art catalysts. This work provides valuable insights for the development of advanced catalysts through P doping and boron vacancy engineering and the design of efficient and sustainable energy conversion systems.

Nanoconfined Ti3C2@in-situ-grown TiO2 and ruthenium triphenylphosphine (Ru-II) coupled g-C3N4 to construct RuP-Ti3C2@TiO2/EC3N4 dual function nanocomposite for enhancing photocatalytic green hydrogen production

Nanoconfined 2D Ti3C2 MXene@ in-situ grown TiO2 and ruthenium (II) complex (triphenylphosphine, RuP) were synchronously attached with exfoliated g-C3N4 to fabricate a RuP-Ti3C2@TiO2/EC3N4 dual function nanotexture for photocatalytic solar hydrogen production. The Ti3C2@TiO2 was obtained through HF etching, whereas 48 h of etching time was optimal, enabling the highest H2 production through TiO2 photoexcitation. The nanoconfined Ti3C2@TiO2 coupled with EC3N4 boosted 2.34 folds more H2 production due to TiO2/EC3N4 heterojunction formation with Ti3C2 as a cocatalyst to trap and transport charge carriers. Coupling ruthenium complex (RuP) was beneficial to inject excited electrons to enhance EC3N4 photoactivation under visible light, whereas Ti3C2 cocatalyst accepted the photogenerated electrons from EC3N4 through in-situ grown TiO2. The optimized RuP-Ti3C2@TiO2/EC3N4 exhibited a H2 production rate of 1772 µmol g−1 h−1, which was 2.91, 5.16 and 18.02 folds higher than using RuP/EC3N4, Ti3C2/EC3N4 and EC3N4 samples, respectively. The synergistic effect of RuP with Ti3C2@TiO2 promoted H2 evolution without any deactivation of surface stability due to providing excited electrons and preventing their recombination over the exfoliated nanotexture of g-C3N4. Using this new approach to constructing dual-function heterojunctions, it is attractive to excite semiconductors and can increase the lifetime of photoinduced charge carriers. This work provides a facile strategy and new design approach to develop highly efficient and low-cost photocatalysts for future solar energy-assisted sustainable energy conversion systems for different applications.

Efficient Hydrogen Evolution on Antiperovskite CuNCo3 Nanowires by Mo Incorporation and its Trifunctionality for Zn Air Batteries and Overall Water Splitting.

The current development of single electrocatalyst with multifunctional applications in overall water splitting (OWS) and zinc-air batteries (ZABs) is crucial for sustainable energy conversion and storage systems. However, exploring new and efficient low-cost trifunctional electrocatalysts is still a significant challenge. Herein, the antiperovskite CuNCo3 prototype, that is proved to be highly efficient in oxygen evolution reaction but severe hydrogen evolution reaction (HER) performance, is endowed with optimum HER catalytic properties by in situ-derived interfacial engineering via incorporation of molybdenum (Mo). The as-prepared Mo-CuNCo3 @CoN nanowires achieve a low HER overpotential of 58 mV@10mA cm-2 , which is significantly higher than the pristine CuNCo3 . The assembled CuNCo3 -antiperovskite-based OWS not only entails a low overall voltage of 1.56 V@10mA cm-2 , comparable to most recently reported metal-nitride-based OWS, but also exhibits excellent ZAB cyclic stability up to 310h, specific capacity of 819.2 mAh g-1 , and maximum power density of 102mW cm-2 . The as-designed antiperovskite-based ZAB could self-power the OWS system generating a high hydrogen rate, and creating opportunity for developing integrated portable multifunctional energy devices.

Lithium-Ion Battery Cathode-Electrolyte Interface

The global energy crisis, consumption of fossil fuels, and the associated environmental issues have stimulated extensive interest in searching for sustainable energy storage and conversion systems. Rechargeable lithium-ion batteries (LIBs) are widely used in mobile devices, hybrid, and electric vehicles. Electrode-electrolyte interface has a strong impact on battery capacity decrease and long-term cycling stability. In order to improve fundamental understanding of the involved phenomena to accelerate the rational design of cathode materials and stable interface, Li(Ni,Co,Mn)O2 (NCM) is a cathode material for rechargeable LIB and also a promising electrocatalyst for oxygen evolution reaction (OER). Their battery performance and catalytic activity are highly correlated to their structures. Multiple processes occurring at the cathode/electrolyte interface led to overall performance degradation. One failure mechanism is the dissolution of transition metals from the cathode. Our efforts employ thin film as a model cathode to monitor the Mn dissolution. Using LiMn2O4 and NCM as cathode materials, we will focus on electrochemical characterization, cation mixing, oxygen evolution, and thin film deposition with controlled crystal structures and composition. We will further introduce our work employing the scanning electrochemical microscope to study LIBs degradation and cathode-electrolyte interface in situ and in real-time.

The Guest Doping Effects of Fe on Bimetallic NiCo Layered Double Hydroxide for Enhanced Electrochemical Oxygen Evolution Reaction: Theoretical Screening and Experimental Verification

AbstractExploring efficient transition‐metal‐based electrocatalysts for oxygen evolution reaction (OER) is imperative but remain challenging for sustainable energy storage and conversion systems. Foreign species doping is a significant regulation strategy to enhance the intrinsic activity of host matrix. However, the potential relationship of structure‐activity caused by guest doping elements is seldom tracked systematically. In this case, both theoretical screening and experimental verification are complementarily employed to investigate the guest doping effects of ten first‐row transition metals (Sc∼Zn) on bimetallic NiCo layered double hydroxide (NiCo‐LDH). As a result, the optimized Fe‐doped NiCo‐LDH is identified as the most promising candidate toward alkaline electrocatalytic OER, which exhibits the quasi‐industrial current density of 1000 mA cm−2 at overpotential of 400 mV. Meanwhile, it also shows impressively long‐term stability of 500 h at 500 mA cm−2 with a negligible activity loss. Moreover, in situ electrochemical Raman spectroscopy unveils the dynamic structure evolution from pre‐catalytic state (Fe‐NiCo‐LDH) to metal oxyhydroxide (Fe‐(NiCo)OOH) during the oxidation reaction, and ab‐initio molecular dynamics simulations are further performed to confirm the thermodynamic stability of activated Fe‐(NiCo)OOH phase. This work provides a promising platform for exploring the critical role of transition metal guest doping on host matrix in developing industrially required OER electrocatalysts.

Efficient Self-Powered Overall Water Splitting by Ni4 Mo/MoO2 Heterogeneous Nanorods Trifunctional Electrocatalysts.

The exploration of cost-effective multifunctional electrodes with high activity toward energy storage and conversion systems, such as self-powered alkaline water electrolysis, is very meaningful, although studies remain quite limited. Herein, a heterogeneous nickel-molybdenum (NiMo)-based electrode is fabricated for the first time as a trifunctional electrode for asymmetric supercapacitor (ASC), hydrogen evolution reaction, and oxygen evolution reaction. The trifunctional electrode consists of Ni4 Mo and MoO2 (denoted Ni4 Mo/MoO2 ) with hierarchical nanorod heterostructure and abundant heterogeneous nanointerfaces creating sufficient active sites and efficient charge transfer for achieving high performance self-power electrochemical devices. The ASC consists of the as-prepared Ni4 Mo/MoO2 positive electrode, showing a broad potential window of 1.6V, and a maximum energy density of 115.6Whkg-1 , while the alkaline overall water splitting (OWS) assembled using the as-prepared Ni4 Mo/MoO2 as bifunctional catalysts only requires a low cell voltage of 1.48V to achieve a current density of 10mAcm-2 in aqueous alkaline electrolyte. Finally, by integrating the Ni4 Mo/MoO2 -based ASC and OWS devices, an aqueous self-powered OWS is assembled, which self-power the OWS to generate hydrogen gas and oxygen gas, verifying great potential of the as-prepared Ni4 Mo/MoO2 for sustainable and renewable energy storage and conversion system.

Facile fabrication of SnSe nanorods embedded in GO nanosheet for robust oxygen evolution reaction

Excessive use of fossil fuels has caused their rapid depletion, resulting in a growing energy crisis as well as many environmental concerns, and prompting the development of the sustainable energy conversion system. In this study, we report GO based SnSe nanomaterial incorporated via the hydrothermal route engaging OER activity. The morphological, structural and textual effects of the material have been measured with scanning electron microscopy (SEM), X-ray diffraction (XRD) and Brunauer Emmett Teller (BET). Furthermore, the kinetic process, active sites, conductivity and stability of the electrode medium of GO, SnSe and GO/SnSe were estimated with electrochemical impedance spectroscopy (EIS), linear sweep voltammetry (LSV), electrochemical active surface area (ECSA) and chronoamperometry under 1.0 M KOH with Ni foam as a conductive substrate. Its electrochemical results depicted the following: the GO based SnSe nanocomposite displayed lesser overpotential around 336 mV to reach a current density around 10 mA cm−2 and Tafel slope of 36 mV dec−1. Cyclic stability and chronoamperometry analysis of GO/SnSe nanocomposite show stability over 35 h. The exceptional electrochemical properties of the GO/SnSe nanocomposite differentiate it as a good material for use in electrical and in many other fields in future.

Recent Progress and Future Directions of Biomass-Derived Hierarchical Porous Carbon: Designing, Preparation, and Supercapacitor Applications

In the past decades, fossil energy depletion, environmental pollution, and greenhouse gas emissions have resulted in serious health threats and ecological imbalances, which prompt researchers to explore green and sustainable supercapacitor energy storage and conversion systems. Biomass is a promising renewable energy source to use for biomass porous carbon for supercapacitor devices because it is renewable and has abundant reserves, a low price, and low pollution carbon energy. To date, although some reports have screened different biomass precursors, carbonization methods, and activation strategies and mechanisms, a comprehensive evaluation and critical review of the correlation among biomass porous carbon properties, including pore structure and surface chemistry, and electrochemical energy storage performances of supercapacitors are absent from a multidisciplinary assessment perspective. Therefore, in this review, we summarize recent advances in the biomass porous carbon synthesis process focusing on different carbonization and activation strategies, point out the scope of applicability and advantages/disadvantages of these methods in supercapacitor applications, and reveal the reaction mechanisms and limitations for commercial production. Then, the relationships among biomass porous carbon properties, including hierarchical porous structure, surface chemistry, specific surface area, and electrochemical performances of supercapacitors are reviewed in detail, which enables researchers to prepare and design advanced materials in a more rational way and facilitates them to explore more cutting-edge energy storage materials. Finally, two effective techniques including heteroatom doping and composite material construction are reviewed to address the general problem of low supercapacitor energy density. This review demonstrates the great potential of biomass porous carbon with superior properties, provides advanced tailoring and design viewpoints for the application fields of high-performance supercapacitors, and is expected to inspire new exploration and boost the practical commercial applications of biomass-derived hierarchical porous carbon material in more energy storage and conversion fields.

Ambient Fast Synthesis of Superaerophobic/Superhydrophilic Electrode for Superior Electrocatalytic Water Oxidation

Developing cost‐effective and facile methods to synthesize efficient and stable electrocatalysts for large‐scale water splitting is highly desirable but remains a significant challenge. In this study, a facile ambient temperature synthesis of hierarchical nickel–iron (oxy)hydroxides nanosheets on iron foam (FF‐FN) with both superhydrophilicity and superaerophobicity is reported. Specifically, the as‐fabricated FF‐FN electrode demonstrates extraordinary oxygen evolution reaction (OER) activity with an ultralow overpotential of 195 mV at 10 mA cm−2 and a small Tafel slope of 34 mV dec−1 in alkaline media. Further theoretical investigation indicates that the involved lattice oxygen in nickel–iron‐based‐oxyhydroxide during electrochemical self‐reconstruction can significantly reduce the OER reaction overpotential via the dominated lattice oxygen mechanism. The rechargeable Zn–air battery assembled by directly using the as‐prepared FF‐FN as cathode displays remarkable cycling performance. It is believed that this work affords an economical approach to steer commercial Fe foam into robust electrocatalysts for sustainable energy conversion and storage systems.

Scalable hierarchical wood/ZnO nanohybrids for efficient mechanical energy conversion

Owing to the hierarchical structure, easy multi-functionalization and favorable mechanical properties, wood could harvest electricity from mechanical energy through piezoelectric behavior. In this work, a scalable method to synthesize wood/ZnO composite with multilayered ZnO morphologies is reported for efficient mechanical energy conversion. The synthesis includes charged wood template fabrication, precursor infiltration, and ZnO hydrothermal growth, resulting in controlled ZnO morphologies and distributions while maintaining the hierarchical structure of the wood. Stereo-digital image correlation (stereo-DIC) investigated the relationship between deformation and piezoelectric performance, which revealed the homogeneous distribution of multilayered ZnO enhance piezoelectric performance. The output voltage of wood/ZnO was 1.5 V under periodic mechanical compression (8–10 N) for 300 cycles, while the output current was 2.91 nA. The scalable synthesis strategy and piezoelectric performance are significant for the design of advanced wood nanocomposites for sustainable and efficient energy conversion systems.

Advance of Prussian Blue-Derived Nanohybrids in Energy Storage: Current Status and Perspective.

Great changes have occurred in the energy storage area in recent years as a result of rapid economic expansion. People have conducted substantial research on sustainable energy conversion and storage systems in order to mitigate the looming energy crisis. As a result, developing energy storage materials is critical. Materials with an open frame structure are known as Prussian blue analogs (PBAs). Anode materials for oxides, sulfides, selenides, phosphides, borides, and carbides have been extensively explored as anode materials in the field of energy conversion and storage in recent years. The advantages and disadvantages of oxides, sulfides, selenides, phosphides, borides, carbides, and other elements, as well as experimental methodologies and electrochemical properties, are discussed in this work. The findings reveal that employing oxides, sulfides, selenides, phosphides, borides, and other electrode materials to overcome the problems of low conductivity, excessive material loss, and low specific volume is ineffective. Therefore, this review intends to address the issues of diverse energy storage materials by combining multiple technologies to manufacture battery materials with low cost, large capacity, and extended service life.

Size-controlled liquid phase synthesis of colloidally stable Co3O4 nanoparticles.

Spinel cobalt(ii,iii) oxide (Co3O4) represents a p-type semiconductor exhibiting promising functional properties in view of applications in a broad range of technological fields including magnetic materials and gas sensors as well as sustainable energy conversion systems based on photo- and electrocatalytic water splitting. Due to their high specific surface area, nanoparticle-based structures appear particularly promising for such applications. However, precise control over the diameter and the particle size distribution is required to achieve reproducible size-dependent properties. We herein introduce a synthetic strategy based on the decomposition of hydroxide precursors for the size-controlled preparation of purified Co3O4 nanoparticles with narrow size distributions adjustable in the range between 3-13 nm. The particles exhibit excellent colloidal stability. Their dispersibility in diverse organic solvents further facilitates processing (i.e. ligand exchange) and opens exciting perspectives for controlled self-assembly of the largely isometric primary particles into mesoscale structures. In view of potential applications, functional properties including absorption characteristics and electrocatalytic activity were probed by UV-Vis spectroscopy and cyclic voltammetry, respectively. In these experiments, low amounts of dispersed Co3O4 particles demonstrate strong light absorbance across the entire visible range and immobilized nanoparticles exhibit a comparably low overpotential towards the oxygen evolution reaction in electrocatalytic water splitting.

N,S-co-doped FeCo Nanoparticles Supported on Porous Carbon Nanofibers as Efficient and Durable Oxygen Reduction Catalysts.

Finding high-performance, low-cost, efficient catalysts for oxygen reduction reactions (ORR) is essential for sustainable energy conversion systems. Herein, highly efficient and durable iron (Fe) and cobalt (Co)-supported nitrogen (N) and sulfur (S) co-doped three-dimensional carbon nanofibers (FeCo-N, S@CNFs) were synthesized via electrospinning followed by carbonization. The as-prepared FeCo-N,S@CNFs served as efficient ORR catalysts in alkaline 0.1 m KOH solutions that were N2 and O2 -saturated. The experimental results revealed that FeCo-N,S@CNFs were highly active ORR catalysts with defect-rich active pyridinic N and pyrrolic N and metal bonds to N and S atom sites, which enhanced the ORR activity. FeCo-N,S@CNFs exhibited a high onset potential (Eonset =0.89 V) and half-wave potential (E1/2 =0.85 V), similar to the electrocatalytic activity of commercial Pt/C. Additionally, the durability of the as-prepared FeCo-N,S@CNFs catalysts was maintained for 14 h with long-term stability and high tolerance to methanol stability, accounting for their excellent catalytic ability. Furthermore, Co-N@CNFs, Fe-N@CNFs, and varying Fe and Co ratios were compared with those of FeCo-N,S@CNFs. Synergistic interactions between metals and heteroatoms were believed to play a significant role in enhancing the ORR activity. Owing to their excellent catalytic reduction ability, the as-prepared FeCo-N,S@CNFs can be widely used in battery-based systems and replace commercial Pt/C in fuel cell applications.