Effective Energy Conversion Research Articles

ZnxMnO2/PPy Nanowires Composite as Cathode Material for Aqueous Zinc‐Ion Hybrid Supercapacitors

ABSTRACTOver the past decade, the extensive consumption of finite energy resources has caused severe environmental pollution. Meanwhile, the promotion of renewable energy sources is limited by their intermittent and regional nature. Thus, developing effective energy storage and conversion technologies and devices holds considerable importance. Zinc‐ion hybrid supercapacitors (ZISCs) merge the beneficial aspects of both supercapacitors and batteries, rendering them an exceptionally promising energy storage method. As an important cathode material for ZISCs, the tunnel structure MnO2 has poor conductivity and structural stability. Herein, the ZnxMnO2/PPy (ZMOP) electrode materials are prepared by hydrothermal method. Doping with Zn2+ is used to enhance its structural stability, while adding polypyrrole to improve its conductivity. Therefore, the fabricated ZMOP cathode presents superb specific capacity (0.1 A g−1, 156.4 mAh g−1) and remarkable cycle performance (82.6%, 5000 cycles, 0.2 A g−1). Furthermore, the assembled aqueous ZISCs with ZMOP cathode and PPy‐derived porous carbon nanotube anode obtain a superb capacity of 109 F g−1 at 0.1 A g−1. Meanwhile, at a power density of 867 W kg−1, the corresponding energy density can achieve 20 Wh kg−1. And over 5000 cycles at 0.2 A g−1, the cycle performance of ZISCs maintains at 86.4%, which exhibits excellent cycle stability. This suggests that ZMOP nanowires are potential cathode materials for superior‐performance aqueous ZISCs.

Performance evaluation of composite phase change materials with varying expanded graphite content in a drawer-type latent heat storage tank

The poor thermal conductivity of single-component phase change materials (PCMs) significantly impacts the operational efficiency of solar combi-systems. There is still a gap in the research on the heat release behavior of composite phase change materials (CPCMs). Therefore, this study investigated the heat release behavior of a self-developed drawer-type heat storage tank by varying the content of expanded graphite (EG) in the CPCMs used in it. Simulation was carried out using COMSOL Multiphysics 6.1, followed by experimentation on a test bench. The average outflow temperature, effective energy conversion (EEC), and heat release rate were used to evaluate the performance of the tanks. Comparing the simulation with experimental results, a maximum error of 8.75 % was obtained, indicating the accuracy of the study. The results indicate that adding EG can significantly improve the thermal conductivity of CPCM, with superior heat release behavior observed when the mass fraction of EG reaches 5 %. Under similar temperatures, the average outflow temperature from a 5 % EG tank is approximately 4.4 °C higher, EEC is 84 % higher, and heat release rate is 1.63 times higher than that from an ordinary thermal tank. Under different temperatures in a 5 % EG tank, increasing by 5 °C results in an average outflow temperature increase of 4.1 °C, EEC increase by a factor of one and an increase in heat release rate by 36 %. This study provides valuable insights for subsequent research on operation strategies for solar combined systems.

An Opportunity for Synergizing Desalination by Membrane Distillation Assisted Reverse-Electrodialysis for Water/Energy Recovery.

Industry, agriculture, and a growing population all have a major impact on the scarcity of clean-water. Desalinating or purifying contaminated water for human use is crucial. The combination of thermal membrane systems can outperform conventional desalination with the help of synergistic management of the water-energy nexus. High energy requirement for desalination is a key challenge for desalination cost and its commercial feasibility. The solution to these problems requires the intermarriage of multidisciplinary approaches such as electrochemistry, chemical, environmental, polymer, and materials science and engineering. The most feasible method for producing high-quality freshwater with a reduced carbon footprint is demanding incorporation of industrial low-grade heat with membrane distillation (MD). More precisely, by using a reverse electrodialysis (RED) setup that is integrated with MD, salinity gradient energy (SGE) may be extracted from highly salinized MD retentate. Integrating MD-RED can significantly increase energy productivity without raising costs. This review provides a comprehensive summary of the prospects, unresolved issues, and developments in this cutting-edge field. In addition, we summarize the distinct physicochemical characteristics of the membranes employed in MD and RED, together with the approaches for integrating them to facilitate effective water recovery and energy conversion from salt gradients and freshwater.

Construction of core-shell W18O49@ZnIn2S4 hollow hierarchical structure for boosted photothermal-assisted photocatalytic H2 production

The development of photocatalysts that maximize the utilization of the solar spectrum is crucial to achieving efficient photocatalysis. Herein, the synthesized W18O49@ZnIn2S4 hollow hierarchical structure exhibits superior photothermal-assisted hydrogen (H2) photocatalytic performance under full solar spectrum irradiation. Within this photocatalyst design framework, the use of hollow spherical W18O49 exploits the Localized Surface Plasmon Resonance (LSPR) effect, resulting in increased light absorption. This imparts additional energy to photogenerate carriers through ZnIn2S4, expediting charge migration and elevating the temperature of the reaction system, consequently facilitating the separation of carriers. Notably, the optimized WO(16h)@ZIS-10 sample shows impressive hydrogen evolution rates of 3.11 mmol g−1 under sunlight exposure and 4.98 mmol g−1 h−1 under composite illumination of AM 1.5G and near-infrared (NIR). Additionally, the study explores the impact of different heating methods on photocatalytic activity in solid-liquid reactions, providing valuable insights into effective solar energy conversion through high-activity solar-assisted photocatalysts.

(Invited) In Situ x-Ray Spectroscopy for Energy Materials

In response to the worldwide surge in energy demand, the materials scientists devote themselves to the search for clean and sustainable energy. Without the development of cutting-edge renewable energy materials, going green has never been simple. The zero-emission future requires a multifaceted approach. Advanced functional materials for more effective energy conversion, storage, and conservation are the universal focus of energy research. Although the ideas for increasing the efficiency of current energy materials in terms of energy conversion, storage, or conservation are clear and straightforward, they are technically challenging. It is difficult to better engineer materials in an efficient manner for a practical use without knowing the fundamental atomic and electronic structures, particularly how they respond under operating conditions. Synchrotron x-ray spectroscopies, including x-ray absorption and emission spectroscopies are powerful tools to study the local unoccupied and occupied electronic states. In addition, employing the in situ technique permits us to monitor the atomic and electronic structure modulations of the energy material at work. An emerging x-ray spectro-microscopic technique, scanning transmission x-ray microscopy, which provides spatially resolved x-ray spectroscopy. The significance of utilizing x-ray spectroscopy for the atomic and electronic structure characterization of several significant energy material systems, such as advanced nanocatalysts, artificial photosynthesis materials, and smart materials, will be discussed in this presentation. Recent developments of in situ technique, a number of recent studies, and energy science-related Tamkang University (TKU) end-stations at the BL45A and BL27A of TPS will also be presented.

Construction of Porous Aromatic Frameworks with Specifically Designed Motifs for Charge Storage and Transport.

ConspectusPorous frameworks possess high porosity and adjustable functions. The two features conjointly create sufficient interfaces for matter exchange and energy transfer within the skeletons. For crystalline porous frameworks, including metal organic frameworks (MOFs) and covalent organic frameworks (COFs), their long-range ordered structures indeed play an important role in managing versatile physicochemical behaviors such as electron transfer or band gap engineering. It is now feasible to predict their functions based on the unveiled structures and structure-performance relationships. In contrast, porous organic frameworks (POFs) represent a member of the porous solid family with no long-range regularity. For the case of POFs, the randomly packed building units and their disordered connections hinder the electronic structural consistency throughout the entire networks. However, many investigations have demonstrated that the functions of POFs could also be designed and originated from their local motifs.In this Account, we will first provide an overview of the design and synthesis principles for porous aromatic frameworks (PAFs), which are a typical family of POFs with high porosity and exceptional stability. Specifically, the functions achieved by the specific design and synthesis of in-framework motifs will be demonstrated. This strategy is particularly intuitive to introduce desired functions to PAFs, owing to the exceptional tolerance of PAFs to harsh chemical treatments and synthetic conditions. The local structures can be either obtained by selecting suitable building units, sometimes with the aid of computational screening, or emerge as the product of coupling reactions during the synthetic process. Radical PAFs can be obtained by incorporating a persistent radical molecule as a building unit, and the rigid and porous framework may facilitate the formation of radical species by trapping spins in the organic network, which could avoid the delocalizing and recombining processes. Alternatively, radical motifs can also be formed during the formation of the framework linkages. The coupling reaction plays an important role in the construction of functional motifs like diacetylene. The highly porous, radical PAFs showed significant performance as anodes of lithium-ion batteries. To improve the charge transport within the framework, the building units and their connecting manner were cohesively considered, and the framework with a fully conjugated backbone was built up. In another case, the explicit product of the cross-coupling reaction ensured the precise assembly of two building units with electron donating and accepting abilities; therefore, the moving direction of photogenerated electrons was rationally controlled. Constructing a fully conjugated backbone or rationally designing a D-A system for charge transfer in porous frameworks introduced exciting properties for photovoltaic and photocatalysis, and their highly porous, stable frameworks improved their functional applications for perovskite solar cells and chemical productions. These investigations shed light on the designable combination of intrinsic functional motifs with highly porous organic frameworks for effective energy storage and conversion.

Parameters Optimization for Electrophoretic Deposition of Mn1.5Co1.5O4 on Ferritic Stainless Steel Based on Multi-Physical Simulation

Solid oxide fuel cells (SOFCs) are an effective and sustainable energy conversion technology. As operating temperatures decrease, metal interconnects and supports are widely employed in SOFCs. It is critical to apply a protective coat on ferritic stainless steel (FSS) to suppress Cr evaporation and element interdiffusion under high temperatures. Electrophoretic deposition (EPD) is a promising approach for depositing metal oxides on FSS substrate. Here, a method based on 3D multi-physical simulation and orthogonal experimental design was proposed to optimize deposition parameters, including applied voltage, deposition time, and electrode distance. The EPD process to deposit Mn1.5Co1.5O4 particles in a suspension of ethanol and isopropanol was simulated and the effects of these three factors on the film thickness and uniformity were analyzed. The results indicate that applied voltage has the greatest impact on deposition thickness, followed by deposition time and electrode distance. Meanwhile, deposition time exhibits a more significant effect on film unevenness than applied voltage. Additionally, the particle-fluid coupling phenomenon was analyzed during the EPD process. In practice, these deposition parameters must be selected appropriately and the deposition time must be controlled to obtain a uniform coating. The proposed method can reduce cost and shorten the design period.

Multicarrier PWM techniques for three phase modular multilevel converter application in MRI systems

This research paper presents about the performance analysis of three phase modular multilevel converter with level shifted (phase disposition pulse width modulation) and phase shifted pulse width modulation (PWM) method. This research not only discusses the significance of different modulation procedures in the context of modular multilevel converters but also carefully evaluates each of their unique performance characteristics. This research is based on the fundamental creation of pulses and patterns that can only be acquired by comparing sinusoidal reference signals with triangular carrier signal. Both levels shifted (phase disposition) and phase shifted PWM procedures are used to calculate the phase output voltage of a converter at 2N+1 level. The output waveform is crucially shaped by these modulation techniques, which also ensure effective energy conversion and lower harmonic content. On the basis of the output voltage waveform's quality, the comparative research is conducted and simulated results were presented.

Numerical analysis of polyethylene based nano-enhanced phase change material in cylindrical storage system

Environmental sustainability encompasses various dimensions like waste management, energy conservation, and environmental impact. The use of waste plastic; Linear Low-density polyethylene (LLDPE) as a phase change material (PCM) offers a sustainable solution for energy and the environment. This study investigates LLDPE/ functionalize graphene composites for latent heat storage using a shell and helical coil for effective energy conversion. The simulation is carried out for constant flux and constant temperature heat supply to understand the influence of nano additives and geometrical parameters such as spiral coil diameter (Dc ), pitch (Pc ), and orientation of storage unit (θ). The result reveals that nano additive influence effectively and reduces the charging time approximately from 20 to 40% for 1–5% of nano-addition. Simulation results reveals that the spiral coil diameter is crucial for melting and heat transmission. The overall melting time is decreased by up to 56% by increasing the spiral coil diameter from 21 to 49 mm for LLDPE while the effect of pitch length variation is found not significant. The constant temperature heating at 160, 250 and 340°C gives effective results for charging time improvement. The geometrical orientations from 0 to 90 degrees report that the horizontal position is the best orientation for energy storage.

Natural ore filter cube decorated polypyrrole for effective thermal management and enhanced solar steam generator

Pursuing environmentally friendly and effective energy conversion technologies inspired research investigations into innovative materials and methods to generate solar steam. Herein, we demonstrate a novel methodology that leverages natural ore filter cubes anchored with polypyrrole (PPy) to enhance solar steam generation and effective thermal management via an in-situ polymerization technique. The natural ore filter cubes (NOFC) serve as a porous framework, offering a large surface area for excellent light absorption and hydrophilic water channels. Meanwhile, the PPy coating improves light absorption and effectively converts solar energy into thermal energy. The fabricated evaporator exhibits exceptional solar absorption capability (93 %), with a broad spectral response ranging from ultraviolet to near-infrared wavelengths (200–2500 nm). Moreover, the presence of PPy promotes an efficient evaporation rate (1.58 kg m-2h−1), resulting in rapid heating and vaporization of water under 1 kW m−2. Natural ore filter cubes with PPy coating offer salt resistance, scalability, and environmental sustainability. Finally, this research presents an exciting way to improve solar steam-generating technology for water desalination and energy conversion applications.

Donor-acceptor covalent organic framework/ZnIn2S4 core-shell structure S-scheme heterostructure for efficient photocatalytic hydrogen evolution

Covalent organic frameworks (COFs) show promising prospect as the photocatalysts with advantages of exceptional light adsorption capability, large specific surface area, and adjustable band structure. However, COFs usually suffer from severe recombination of photogenerated carriers. Therefore, there is an urgent demand to design effective COF-based heterostructures to enhance the separation of carriers. In this work, a porphyrin-based COF with electron donor-acceptor structure is synthesized via condensation polymerization by using 5,10,15,20-tetrakis(4-aminophenyl)porphyrin (TAPPP) and N,N,N',N'-tetra(4-formylphenyl)benzidin (NFPBD) as the donor and acceptor, respectively. Subsequently, ZnIn2S4 (ZIS) are successfully in-situ grown on the surface of porphyrin-based COF, forming a novel core-shell structure. The in-situ synthesized ZIS with positive charges can be easily adsorbed on the negatively charged sites of the COF’s surface via the electrostatic interaction. This organic/inorganic hybrid COF-ZIS heterostructure exhibits a superior photocatalytic hydrogen evolution (PHE) rate of 695 μmol g−1 h−1, approximately three times higher than that of ZIS. The construction of COF-ZIS heterostructure plays an important role in enhancing the separation and transport of photogenerated carriers, which provides more electrons at the surface of ZIS to take part in proton reduction. Electron paramagnetic resonance spectra confirm the charge carriers transfer mode in the COF-ZIS heterostructure via an S-scheme mechanism. Moreover, upon loading Pt as the cocatalyst, the heterostructure achieves an effective PHE rate of 2711 μmol g−1 h−1 along with an exceptional stability. Additionally, the COF-ZIS heterostructure reaches up to 2.45% of apparent quantum efficiency at 400 nm. Notably, the average lifetime of the COF-ZIS heterostructure increases by 43.2% and 98.9% compared to that of ZIS and the COF individually, as observed through single-particle fluorescence spectroscopy. This work gives valuable inspiration into the building of donor-acceptor COF-based S-scheme heterostructures to achieve highly effective green energy conversion by aligning band structures.

Drivers of Magnetic Field Amplification at Oblique Shocks: In Situ Observations

Collisionless shocks are ubiquitous structures throughout the Universe. Shock waves in space and astrophysical plasmas convert the energy of a fast-flowing plasma to other forms of energy, including thermal and magnetic energies. Plasma turbulence and high-amplitude electric and magnetic fluctuations are necessary for effective energy conversion and particle acceleration. We survey and characterize in situ observations of reflected ions and magnetic field amplification rates at quasiperpendicular shocks under a wide range of upstream conditions. We report magnetic amplification rates as high as 25 in our current data set. Reflected ions interacting with the incoming plasma create magnetic perturbations that cause magnetic amplification in upstream and downstream regions of quasiperpendicular shocks. Our observations show that, in general, magnetic amplification increases with the fraction of reflected ions, which itself increases with Mach number. Both parameters plateau once full reflection is reached. Magnetic amplification continuously increases with the inverse of the magnetization parameter of the upstream plasma. We find that the extended foot region upstream of shocks and nonlinear processes within that region are key factors for intense magnetic amplification. Our observations at nonrelativistic shocks provide the first experimental evidence that below a certain magnetization threshold, the magnetic amplification efficiency at quasiperpendicular shocks becomes comparable to that at the quasiparallel shocks.

A high-temperature solar selective absorber based on one-dimensional multilayer nanostructures

Selective absorbers play a crucial role in harvesting solar energy and realizing effective solar-thermal energy conversion in concentrated solar power systems and thermophotovoltaic systems. This study focuses on obtaining a high-temperature solar selective absorber which can well balance its thermal performance as well as structural complexity. Based on this, a selective absorber with simple one-dimensional multilayer nanostructures is designed to adapt to the high-temperature operation environments. The obtained absorber exhibits a total solar absorptance of 0.9504 to the AM1.5 solar radiation. Taking into account the infrared radiation loss, the solar-thermal efficiency of the absorber is found to be 91.2% under 1000 suns at 1273 K, and the total emittance is 0.1504 at the corresponding temperature. The absorber shows high insensitivity to both incident polarization angles and wide-angle incidence. Analysis of impedance and electromagnetic field distribution indicates that the selective absorption performance of the absorber is attributed to its impedance matching properties, resulting from the coupling effect of surface plasmon polaritons and magnetic polaritons.

Broadband mirrors for thermophotovoltaics.

We present an innovative solution to improve the efficiency of thermophotovoltaic (TPV) devices by tackling the problem of sub-bandgap photon losses. We propose an optimized design for thin-film mirrors using inverse electromagnetic design principles, thereby enhancing the average reflectivity and photon re-use. Our method surpasses the traditional Bragg mirror by employing a gradient-descent based optimization over Bragg mirror geometrical parameters, leveraging the transfer matrix method for derivative calculations. The optimized structure, based on continuously chirped distributed Bragg reflectors proposed herein demonstrates a remarkable increase in reflectivity beyond 98%, over an almost three-octaves bandwidth (0.1eV-0.74eV). We show that the incident power loss in InGaAs TPV cells at an emitter temperature of 1200°C is significantly reduced. While our work shows considerable promise, further exploration is needed to ascertain the practicability and robustness of these designs under various operational conditions. This study thus provides a major step forward in TPV technology, highlighting a new route towards more effective energy conversion systems.

Advanced Design of Light‐Assisted Nanogenerators with Multifunctional Perovskites

AbstractEnormous efforts are invested in developing multi‐energy harvesting technology with simple configuration and high conversion efficiency, and light‐assisted nanogenerators are considered a promising solution. Multifunctional perovskites are explored for this light‐assisted nanogenerator, owing to its powerful platform characteristics for integrating multiple energy conversion mechanisms and multi‐effects coupling phenomenon. Therefore, with the rapid progress of this emerging field, a timely and comprehensive review of this light‐assisted nanogenerator is urgently needed for updating the fundamental understanding of coupling mechanism and material‐device‐performance relationship. In this review, recent advancements of the perovskite light‐assisted nanogenerator with their advanced designs are presented. First, the fundamental properties co‐existing in perovskites are briefly introduced, as well as some emerging effects (e.g., flexoelectric). Subsequently, the further coupling mechanism between photovoltaic effect and other energy conversion effects in different light‐assisted nanogenerator are discussed in categories. And the output characteristics and potential application of various coupled devices are systematically described from the perspective of perovskites selection and device engineering. Finally, some perspectives on existing challenges and further development for light‐assisted nanogenerator are put forward, with the aim to provide useful guidance for the design of advanced devices.

Structure-based screening of sp2 hybridized small donor bridges as donor: acceptor switches for optical and photovoltaic applications: DFT way.

This research aims to investigate the potential of pyrazine-based small donor moieties as donor-acceptor switches for optical and photovoltaic applications. The designed organic dyes have a high light harvesting efficiency (LHE) and can potentially generate significant electrical energy. The study focuses on understanding the structural and electronic properties of these dyes through the analysis of dihedral angles, bond lengths, and energies of frontier molecular orbitals The UV-Vis spectroscopy parameters of the designed organic dyes revealed their absorption characteristics, including transition energies, wavelengths (λmax), and oscillator strengths (f). The photovoltaic properties of the developed organic dyes show a range of values: a range of 0.95-0.99 for LHE and a range of 1.77-33.02 W for maximum power output (Pmax) with the highest value for dye DDP5. For their stabilization energies, their natural bond orbitals had values ranging from 0.56 to 128.48kcal/mol, their E(j)E(i) values from 0.22 to 1.29 a.u, and their Fi,j values from 0.024 to 0.213kcal/mol. Out of all dyes, the DDP5 produced highest push-pull effect and can be good choice for further studies. The design of these novel organic materials for effective and economical solar energy conversion will be aided by evaluating the potential of 5,10-diphenyl-5,10-dihydrophenazine as a donor moiety and determining the structure-property correlations controlling the photovoltaic performance of the compounds.

Enhanced piezoelectric properties in low-temperature sintered Pb(Zr,Ti)O3-based ceramics via Yb2O3 doping

Pb(Mg[Formula: see text]W[Formula: see text])O3–Pb(Ni[Formula: see text]Nb[Formula: see text])O3–Pb(Zr[Formula: see text]Ti[Formula: see text])O3 (PNN–PMW–PZT) piezoceramics were sintered at a low temperature of 900∘C by the mixed metal oxide powder solid-state reaction route. CaCO3 and Li2CO3 as sintering aids and Yb2O3 as a dopant were added into the PNN–PMW–PZT ceramic system for low-temperature sintering and enhancement of electrical properties, respectively. The effects of different Yb2O3 doping amounts on the microstructure, dielectric, piezoelectric and ferroelectric properties of the samples were systematically investigated. The piezoceramics doped with 0.1[Formula: see text]mol% Yb2O3 have optimal electrical properties ([Formula: see text][Formula: see text]pC/N, [Formula: see text], [Formula: see text] (1[Formula: see text]kHz), [Formula: see text] (1[Formula: see text]kHz), and [Formula: see text]C). While the piezoceramics doped with 0.3[Formula: see text]mol% Yb2O3 have optimal energy conversion properties: the piezoelectric voltage coefficient [Formula: see text][Formula: see text]Vm/N and the effective piezoelectric energy conversion coefficient [Formula: see text][Formula: see text]m2/N.

Two-dimensional Be2P4 as a promising thermoelectric material and anode for Na/K-ion batteries.

Incredibly effective and flexible energy conversion and storage systems hold great promise for portable self-powered electronic devices. Owing to their large surface area, exceptional atomic structures, superior electrical conductivity and good mechanical flexibility, two-dimensional (2D) materials are recognized as an attractive option for energy conversion and storage application. In this work, we examined the stability, electronic, thermoelectric and electrochemical aspects of a novel 2D Be2P4 monolayer by adopting density functional theory (DFT). The Be2P4 monolayer exhibits a direct semiconductor gap of 0.9 eV (HSE06), large Young's modulus (∼198 GPa), high carrier mobility (∼104 cm2 V-1 s-1) and a low excitonic binding energy of 0.11 eV. Our calculated findings suggest that Be2P4 shows a lattice thermal conductivity of 1.02 W m K-1 at 700 K, resulting in moderate thermoelectric performance (ZT ∼ 0.7), encouraging its use in thermoelectric materials. In addition, a higher adsorption energy of -2.28 eV (-2.52 eV) and less diffusion barrier of 0.22 eV (0.17 eV) for Na(K)-ion batteries promote fast ion transport in the Be2P4 monolayer. This material also shows a high specific capacity and superior energy density of 8460 W h kg-1 (8883 W h kg-1) for Na(K)-ion batteries. Thus, our results offer insightful information for investigating potential thermoelectric and flexible anode materials based on the Be2P4 monolayer.

Natural tea polyphenol functionalized graphene anode for simultaneous power production and degradation of methyl orange dye in microbial fuel cells.

The microbial fuel cell (MFCs) has dual functions, capable of achieving dye decolorization and synchronous power generation. Despite these advantages, the MFCs have faced challenges related to low electron transfer efficiencies and limited dye treatment capacity in wastewater applications. This work introduces an innovative approach by employing reduced graphene oxide-modified carbon cloth (TP-RGO@CC) anodes, utilizing tea polyphenols as the reducing agent. This modification significantly enhances the hydrophilicity and biocompatibility of the anodes. The MFC equipped with the TP-RGO@CC anode demonstrated a remarkable increase in the maximum power density, reaching 773.9 mW m-2, representing a 22% improvement over the plain carbon cloth electrode. The decolorization rate of methyl orange (50 mg L-1, pH 7) reached 99% within 48 h. Biodiversity analysis revealed that the TP-RGO@CC anode selectively enriched electrogens producing and organic matter-degrading bacteria, promoting a dual mechanism of dye decolorization, degradation, and simultaneous electro-production at the anode. This work highlights advanced anode materials that excel in effective pollutant removal, energy conversion, and biomass reuse.

Modification of carbon nanofibers for boosting oxygen electrocatalysis.

Oxygen electrocatalysis is a key process for many effective energy conversion techniques, which requires the development of high-performance electrocatalysts. Carbon nanofibers featuring good electronic conductivity, large specific surface area, high axial strength and modulus, and good resistance toward harsh environments have thus been recognized as reinforcements in oxygen electrocatalysis. This review summarizes the recent progress on carbon nanofibers as electrocatalysts for oxygen electrocatalysis, with special focus on the modulation of carbon nanofibers for further elevating their electrocatalytic performance, which includes morphological and structural engineering, surface and pore size distribution, defect engineering, and coupling with other electroactive materials. Additionally, the correlation between the geometrical/electronic structure of their active centers and electrocatalytic activity is systematically discussed. Finally, conclusions and perspectives of this interesting research field are presented, which we hope will provide guidance for the future fabrication of more advanced carbon-fiber-based electrocatalysts.