Search

Microbial fuel cells (MFCs) benefit from the introduction of iron in the anode, as its multiple valence states and high electron‐catalytic activity led to improved power densities in MFCs. However, the effect of long‐term Fe3+ release into the electrolyte on the power density of MFCs is often overlooked. Herein, an anode consisting of a three‐dimensional iron foam uniformly coated by reduced graphene oxide (rGO/IF) with a suitable loading density (8 g/m2) and a large specific surface area (0.05 m2/g) for high‐density bacterial loading was prepared. The hybrid cells based on the rGO/IF anode exhibit a maximum power density of 5330 ± 76 mW/m2 contributed by MFCs and galvanic cells. The rGO/IF anode enables continuous Fe3+ release for high electron‐catalytic activity in the electrolyte during the discharging of the galvanic cells. As a result, the hybrid cells showed a power density of 2107 ± 64 mW/m2 after four cycles, facilitated through reversible conversion between Fe3+ and Fe2+ in the electrolyte to accelerate electron transfer efficiency. The results indicate that the rGO/IF anode can be used for designing and fabricating high‐power MFCs by optimizing the rate of release of Fe3+ in the electrolyte. [ABSTRACT FROM AUTHOR]

Carbon-based nanomaterials, such as graphene, carbon nanotubes, fullerenes, and carbon quantum dots, have gained attention for their exceptional properties in electrical conductivity, thermal conductivity, mechanical strength, and optical properties. These materials have applications in electronic devices, energy storage, environmental protection, and biomedicine. However, challenges remain in terms of synthesis, functionalization, and integration with other materials. Future research aims to improve manufacturing processes, enhance performance, and develop novel electronic devices and energy storage systems. The sustainability and environmental friendliness of carbon-based materials are also important considerations. [Extracted from the article]

Photoisomerization‐induced phase change are important for co‐harvesting the latent heat and isomerization energy of azobenzene molecules. Chemically optimizing heat output and energy delivery at alternating temperatures are challenging because of the differences in crystallizability and isomerization. This article reports two series of asymmetrically alkyl‐grafted azobenzene (Azo‐g), with and without a methyl group, that have an optically triggered phase change. Three exothermic modes were designed to utilize crystallization enthalpy (∆Hc) and photothermal (isomerization) energy (∆Hp) at different temperatures determined by the crystallization. Azo‐g has high heat output (275–303 J g−1) by synchronously releasing ∆Hc and ∆Hp over a wide temperature range (−79 °C to 25 °C). We fabricated a new distributed energy utilization and delivery system to realize a temperature increase of 6.6 °C at a temperature of −8 °C. The findings offer insight into selective utilization of latent heat and isomerization energy by molecular optimization of crystallization and isomerization processes. [ABSTRACT FROM AUTHOR]

Molecular solar thermal (MOST) systems employ molecular photoswitches to store or release solar energy as heat under specific conditions. Among these systems, azobenzene (Azo) derivatives are particularly noteworthy owing to their superior photoresponsive properties and efficient reversible isomerization. Recent pioneering studies have focused on the molecular design of Azo derivatives to enhance the energy storage performance. Phase-change Azo (PC-Azo) derivatives—fabricated by integrating molecular photoswitches with phase-change materials—capture both the enthalpy of phase change and that of isomerization, thereby considerably increasing the energy storage density of Azo. This research provides a review of the crucial performance parameters of PC-Azo-based MOST systems and delves into the factors influencing the phase change and isomerization of PC-Azo derivatives to provide guidelines for the application of machine learning in MOST systems. A key focus of the research is the application of theoretical computing and machine learning in recent molecular design advancements. The study emphasizes the importance of employing machine learning techniques in the molecular design of PC-Azo derivatives, underlining their potential in facilitating the targeted design of photothermal energy storage materials. This approach marks a significant stride in the field, offering innovative avenues for the development of advanced energy storage solutions. [ABSTRACT FROM AUTHOR]

In recent years, with the rapid advancement in various high-tech technologies, efficient heat dissipation has become a key issue restricting the further development of high-power-density electronic devices and components. Concurrently, the demand for thermal comfort has increased; making effective personal thermal management a current research hotspot. There is a growing demand for thermally conductive materials that are diversified and specific. Therefore, smart thermally conductive fiber materials characterized by their high thermal conductivity and smart response properties have gained increasing attention. This review provides a comprehensive overview of emerging materials and approaches in the development of smart thermally conductive fiber materials. It categorizes them into composite thermally conductive fibers filled with high thermal conductivity fillers, electrically heated thermally conductive fiber materials, thermally radiative thermally conductive fiber materials, and phase change thermally conductive fiber materials. Finally, the challenges and opportunities faced by smart thermally conductive fiber materials are discussed and prospects for their future development are presented. [ABSTRACT FROM AUTHOR]

Optimizing the structure of electrode materials is one of the most effective strategies for designing high‐power microbial fuel cells (MFCs). However, electrode materials currently suffer from a series of shortcomings that limit the output of MFCs, such as high intrinsic resistance, poor electrolyte wettability, and low microbial load capacity. Here, a three‐dimensional (3D) nitrogen‐doped multiwalled carbon nanotube/graphene (N‐MWCNT/GA) composite aerogel is synthesized as the anode for MFCs. Comparing nitrogen‐doped GA, MWCNT/GA, and N‐MWCNT/GA, the macroporous hydrophilic N‐MWCNT/GA electrode with an average pore size of 4.24 µm enables high‐density loading of the microbes and facilitates extracellular electron transfer with low intrinsic resistance. Consequently, the hydrophilic surface of N‐MWCNT can generate high charge mobility, enabling a high‐power output performance of the MFC. In consequence, the MFC system based on N‐MWCNT/GA anode exhibits a peak power density and output voltage of 2977.8 mW m−2 and 0.654 V, which are 1.83 times and 16.3% higher than those obtained with MWCNT/GA, respectively. These results demonstrate that 3D N‐MWCNT/GA anodes can be developed for high‐power MFCs in different environments by optimizing their chemical and microstructures. [ABSTRACT FROM AUTHOR]