Principles of Magnetic Hyperthermia: A Focus on Using Multifunctional Hybrid Magnetic Nanoparticles

Hyperthermia is a noninvasive method that uses heat for cancer therapy where high temperatures have a damaging effect on tumor cells. However, large amounts of heat need to be delivered, which could have negative effects on healthy tissues. Thus, to minimize the negative side effects on healthy cells, a large amount of heat must be delivered only to the tumor cells. Magnetic hyperthermia (MH) uses magnetic nanoparticles particles (MNPs) that are exposed to alternating magnetic field (AMF) to generate heat in local regions (tissues or cells). This cancer therapy method has several advantages, such as (a) it is noninvasive, thus requiring surgery, and (b) it is local, and thus does not damage health cells. However, there are several issues that need to achieved: (a) the MNPs should be biocompatible, biodegradable, with good colloidal stability (b) the MNPs should be successfully delivered to the tumor cells, (c) the MNPs should be used with small amounts and thus MNPs with large heat generation capabilities are required, (d) the AMF used to heat the MNPs should meet safety conditions with limited frequency and amplitude ranges, (e) the changes of temperature should be traced at the cellular level with accurate and noninvasive techniques, (f) factors affecting heat transport from the MNPs to the cells must be understood, and (g) the effect of temperature on the biological mechanisms of cells should be clearly understood. Thus, in this multidisciplinary field, research is needed to investigate these issues. In this report, we shed some light on the principles of heat generation by MNPs in AMF, the limitations and challenges of MH, and the applications of MH using multifunctional hybrid MNPs

Selective integration of hierarchical nanostructured energy materials : an effective approach to boost the energy storage performance of flexible hybrid supercapacitors

High energy density, fast charge–discharge capability, high flexibility, and sustained cycle life are the key challenges in the application of flexible supercapacitors (SCs) in modern electronics. These primary requirements could be accomplished by engineering a new class of current collectors consisting of hierarchical combinations of various active materials. This study reports the selective integration of hierarchical Ni(OH)₂ nanoneedle arrays with NiO–NiCo₂O₄ nanosheet arrays (Ni(OH)₂ NNAs@NiO–NiCo₂O₄ NSAs) on flexible fabric for high-performance electrodes. The novel core–shell-like hetero-nanoarchitectures not only enhance the electrochemical activity and specific surface area but also, more importantly, provide superhighways for the ultrafast transport of electrons and ions. As a battery-type material, the core–shell-like Ni(OH)₂ NNAs@NiO–NiCo₂O₄ NSAs display a high specific capacity of 326.7 mA h g⁻¹ at 2 A g⁻¹ in aqueous 3 M KOH; this value is 1.89, 1.23 and 1.14 times those of NiO–NiCo₂O₄, NiO@NiO–NiCo₂O₄ and Co₃O₄@NiO–NiCo₂O₄ electrodes, respectively. Most importantly, a flexible hybrid SC (FHSC, Ni(OH)₂ NNAs@NiO–NiCo₂O₄ NSAs//graphene-ink) demonstrates a superhigh energy density of 97.1 W h kg⁻¹ and a superior long cycling lifespan with 94.7% retention over 5000 cycles. Utilizing these excellent energy storage properties, the fabricated FHSC operated a multifunction electronic display and light up different colored light emitting diodes for real-time applications.This work was supported by BK 21 PLUS, Creative Human Resource Development Program for IT Convergence, Pusan National University, Busan, South Korea

CNT@rGO@MoCuSe Composite as an Efficient Counter Electrode for Quantum Dot-Sensitized Solar Cells

This paper reports an efficient and simple strategy for the synthesis of molybdenum copper selenide (MoCuSe) nanoparticles decorated with a combination of a carbon nanotube (CNT) network and reduced graphene oxide (rGO) nanosheets to form an integrated hybrid architecture (CNT@rGO@MoCuSe) using a two-step hydrothermal approach. The synthesized hybrid CNT@rGO@MoCuSe material onto the Ni foam substrate is applied successfully as an effective counter electrode (CE) in quantum dot-sensitized solar cells (QDSSCs). A highly conductive CNT@rGO network grown on electrochemically active MoCuSe particles provides a large surface area and exhibits a rapid electron transport rate at the interface of CE/electrolyte. As a result, the QDSSC with the designed CNT@rGO@MoCuSe CE shows a higher power conversion efficiency of 8.28% under 1 sun (100 mW cm^–2) irradiation, which is almost double the efficiency of 4.04% for the QDSSC with the MoCuSe CE. Furthermore, the QDSSC based on the CNT@rGO@MoCuSe CE delivers superior stability at a working state for over 100 h. Therefore, CNT@rGO@MoCuSe is very promising as a stable and efficient CE for QDSSCs and offers new opportunities for the development of hybrid, effective, and robust materials for energy-related fields

A Novel Off-Grid Optimal Hybrid Energy System for Rural Electrification of Tanzania Using a Closed Loop Cooled Solar System

A large proportion of the world’s populations live in developing countries. Rural areas in many of these countries are isolated geographically from grid connections and they have a very low rate of electrification. The uninterrupted power supply (UPS) in these regions is a considerable challenge. The use of renewable energy resources (RER) in an off-grid hybrid energy system can be a pathway to solving this problem. Tanzania has a very low electrification rate (rural 16.9%, urban 65.3%). This paper discussed, described, designed a novel uninterruptible, and environmental friendly solar-wind hybrid energy system (HES) for remote area of Tanzania having closed loop cooled-solar system (CLC-SS). An optimized configuration for the proposed HES was obtained by Hybrid Optimization Model for Electric Renewable (HOMER) analysis software using local solar and wind resources. The designed CLC-SS improved the efficiency of the hybrid solar-wind systems by extracting more power from the solar modules. An evaluation of CLC-SS revealed a 10.23% increase in power output from conventional solar PV modules. The results validate that the optimized system’s energy cost (COE) is 0.26 $/kWh and the net present cost (NPC) of the system is$7110.53. The enhanced output solar wind hybrid system, designed in this paper is cost-effective and can be applied easily to other regions of the world with similar climate conditions

Development of Novel and Ultra-High-Performance Supercapacitor Based on a Four Layered Unique Structure

This paper presents an electrode with a core/shell geometry and a unique four-layered porous wrinkled surface for pseudocapacitive supercapacitor applications. To design the electrode, Ni foam was used as a substrate, where the harmonious features of four constituents, ZnO (Z), NiS (N), PEDOT:PSS (P), and MnO2 (M) improved the supercapacitor electrochemical performance by mitigating the drawbacks of each other component. Cyclic voltammetry and galvanostatic charge discharge measurements confirmed that the ZNPM hybrid electrode exhibited excellent capacitive properties in 2 M KOH compared to the ZNP, ZN, and solely Z electrodes. The ZNPM electrode showed superior electrochemical capacitive performance and improved electrical conductivity with a high specific capacitance of 2072.52 F g−1 at 5 mA, and a high energy density of 31 Wh kg−1 at a power density of 107 W kg−1. Overall, ZNPM is a promising combination electrode material that can be used in supercapacitors and other electrochemical energy conversion/storage devices

Recent Advancements of Polyaniline/Metal Organic Framework (PANI/MOF) Composite Electrodes for Supercapacitor Applications: A Critical Review

Supercapacitors (SCs), also known as ultracapacitors, should be one of the most promising contenders for meeting the needs of human viable growth owing to their advantages: for example, excellent capacitance and rate efficiency, extended durability, and cheap materials price. Supercapacitor research on electrode materials is significant because it plays a vital part in the performance of SCs. Polyaniline (PANI) is an exceptional candidate for energy-storage applications owing to its tunable structure, multiple oxidation/reduction reactions, cheap price, environmental stability, and ease of handling. With their exceptional morphology, suitable functional linkers, metal sites, and high specific surface area, metal–organic frameworks (MOFs) are outstanding materials for electrodes fabrication in electrochemical energy storage systems. The combination of PANI and MOF (PANI/MOF composites) as electrode materials demonstrates additional benefits, which are worthy of exploration. The positive impacts of the two various electrode materials can improve the resultant electrochemical performances. Recently, these kinds of conducting polymers with MOFs composites are predicted to become the next-generation electrode materials for the development of efficient and well-organized SCs. The recent achievements in the use of PANI/MOFs-based electrode materials for supercapacitor applications are critically reviewed in this paper. Furthermore, we discuss the existing issues with PANI/MOF composites and their analogues in the field of supercapacitor electrodes in addition to potential future improvements