Nano

In today’s energy wars, the decrease in fossil fuels and the increase in pollution reuses the question of energy and clean merit production. For this reason, supercapacitor electrodes are available for supercapacitor applications, which are synthesized using biodegradable materials or hybrids by taking nature as an example. In synthesizing our example electrode pectin, we will examine the methods of obtaining pectin, which is abundant in nature and can be used effectively in terms of its physicochemical properties, by purification or synthesis methods. Supercapacitors are essential in storing energy with their fast charge/discharge properties. This includes using pectin and other materials in energy storage systems. We will present other materials preferred in supercapacitor applications and modified compilations of these applications. In conclusion; a porous material such as pectin has a large surface area. Materials with large surface areas are very suitable electrodes for charge storage in supercapacitor applications. If some problems in pectin production and electrical conductivity can be resolved, it will be a very suitable natural electrode material for supercapacitors.

Thulium tellurite (${\mathrm{\text{TmTeO}}}_3$) is synthesized by hydrothermal method. It exhibits nearly cuboid-shaped particles along with triangular particles. ${\mathrm{\text{TmTeO}}}_3$ is found to be monoclinic. The energy gap is 5.87eV, the Urbach energy value is 0.287eV and the refractive index is 1.881. The size of the particle is determined as 107nm. Optical transitions between energy levels assign absorption and emission peaks. Tm, was found in the oxide matrix as Tellurite. Magnetic susceptibility between 20K and 300K decreases with temperature, reaches saturation and aligns all Thulium spins. M–H curve confirms paramagnetic nature at 300K and feeble ferromagnetic nature at 77K. Cyclic voltammogram and chronopotentiometry analysis exhibit pseudo-capacitive behavior. The potential window is 0.82. Specific capacitance is found to be 87F/g. Chronopotentiometry analysis shows 55F/g specific capacitance. Impedance analysis shows a pseudo-capacitive nature. ${\mathrm{\text{TmTeO}}}_3$ symmetrical supercapacitor device is fabricated with potential window of 1.52V. A specific capacitance of 37.75F/g at 1 A/g, energy density 6.055Wh kg${}^{-1}$ and power density 760.99W kg${}^{-1}$ was achieved. Impedance analysis shows low series resistance of 2.567$\mathrm{\Omega }$ and charge transfer resistance of 0.473$\mathrm{\Omega }$. Cyclic performance with 80% specific capacitance retention is observed after 5000 cycles. The ${\mathrm{\text{TmTeO}}}_3$ symmetric supercapacitor electrodes possess good electrochemical properties due to wider potential window, long cycle stability and notable energy density.

Titanium dioxide (${\mathrm{\text{TiO}}}_2$) is a commonly employed electron transport layer in perovskite solar cells (PSCs) due to its exceptional attributes such as high mobility, a wide bandgap and remarkable stability against moisture and high temperatures. This holds particularly true for inorganic PSCs. Nevertheless, the substantial hysteresis and elevated trap defect levels following annealing present challenges to enhance the efficiency of the PSCs. Herein, we proposed a chemical bath deposition (CBD) method to fabricate the ${\mathrm{\text{TiO}}}_2$ layer, serving as the electron transport layer in ${\mathrm{\text{CsPbBr}}}_3$ solar cells. This method is coupled with KCl, which supplies an ample quantity of $K$ ions capable of diffusing into the ${\mathrm{\text{CsPbBr}}}_3$ perovskite film during the annealing process. The inclusion of $K$ ions significantly diminishes the solar cell hysteresis and enhances the crystalline quality of the perovskite material, thereby enhancing the performance of ${\mathrm{\text{CsPbBr}}}_3$ solar cells. By implementing the ${\mathrm{\text{TiO}}}_2$ and KCl treatments, we achieved an impressive efficiency of 9.49%. Furthermore, the device also exhibited excellent stability in air for 30 days.

Antimony-based materials possess high theoretical capacities and suitable potential, which could be promising anode materials for sodium-ion batteries (SIB). However, poor stabilities and sluggish kinetics are drawbacks. Building heterojunction is an ideal method to solve these issues. Its unique structure develops internal electric fields spontaneously to boost the charge transport and relieve stress. Nevertheless, the controllable preparation of face-to-face (2D) heterojunctions is still hard-pressed. Herein, ${\mathrm{\text{Sb}}}_2{\mathrm{\text{Te}}}_3$–$\mathrm{\text{Te}}$ nanoheterojunctions, which consist of two-dimensional ${\mathrm{\text{Sb}}}_2{\mathrm{\text{Te}}}_3$–$\mathrm{\text{Te}}$ nanoblades attached to a one-dimensional Te nanorod, are fabricated through a two-step solvothermal method. Among that, the density of nanoblades is adjustable through the engineering feed ratio. When employed as anodes for SIBs, ${\mathrm{\text{Sb}}}_2{\mathrm{\text{Te}}}_3$–$\mathrm{\text{Te}}$ nanoheterojunctions display a reversible capacity of 463.2mAhg${}^{-1}$ at 100mAg${}^{-1}$. Even a capacity of 305.5mAhg${}^{-1}$ remains after 1000 cycles under a high current of 1.5Ag${}^{-1}$. Moreover, the density functional theory (DFT) calculations also identify the high conductivity of heterojunction. This work offers an effective way to design the structures and properties of heterojunctions, further expanding their application range.

Chronic ingestion of food containing clenbuterol (CLB) in the human body can cause acute poisoning. Thus, it is essential to develop a sensitive CLB detection way. Here, a novel electrochemical aptamer sensor based on aptamer/gold nanoparticles/amino magnetic ferric oxide/graphene nanosheets (aptamer/Au NPs/Fe₃O₄–NH₂/GN) nanocomposite has been developed. The Fe₃O₄–NH₂ nanoparticles were self-assembled on GN, and then Fe₃O₄–NH₂/GN nanocomposite was coated on the glassy carbon electrode (GCE) surface. Afterward, Au NPs were electrodeposited on Fe₃O₄–NH₂/GN nanocomposite to fix the aptamer by the Au–S bonds. When CLB was added to the solution, the aptamer will specifically recognize CLB, causing current changes. Under the optimized conditions, the sensor shows better electrochemical performance (linear range is $1\times 10^{-13}$M to $1\times 10^{-7}$M, the detection limit is $1.16\times 10^{-14}$M ($S/N=3$)). It has been successfully applied to the detection of CLB in actual samples. The results show that the aptamer sensor has good selectivity, stability and repeatability, which will provide a novel idea for more sensitive and quicker CLB detection.

Nanobiochar exhibits promising applications across a spectrum of fields due to its exceptional physicochemical properties. Ball milling, a prominent nanobiochar synthesis method, is influenced by process factors and biochar pretreatments, yet dominant controls still remain uncertain. In this study, the apple branch bulk biochar (pyrolyzed under ${350}^{\circ }$C) was ball milled under different milling speeds, ball-to-powder mass ratios, and milling durations to investigate the optimal process parameter combinations for ball milling method. Then, we evaluated the impact of pyrolysis temperature and pretreatment temperature of bulk biochar on ball milling effect using optimized parameter combinations. Subsequently, the physicochemical properties of the bulk biochar and nanobiochar were measured. The results showed that high speed with low ball-to-powder mass ratio, low speed with high ball-to-powder mass ratio, and high pyrolysis temperature could significantly decrease the particle sizes of nanobiochar. Ball milling duration and pretreatment temperature had no significant effect on the particle sizes of biochar. The optimal combination of the rotational speed, ball-to-powder mass ratio and milling duration was 400 RPM, 100:1, 2h and 700 RPM, 20:1, 2h. The bulk biochar pyrolyzed at ${550}^{\circ }$C could be milled into biochar nanoparticles with an average particle size smaller than 100nm via above parameters. Nanobiochar shows improved properties such as specific surface area, cation exchange capacity, and surface functional groups over bulk biochar. This study provides a scientific basis for the widespread application of ball milling in the field of preparing nanobiochar.

Natural melanin is a sustainable and environmentally friendly pigment. The structural properties of melanin are of great significance for its functional applications. In this study, the preliminary composition and structure of melanin extracted from the induced cultures of Lasiodiplodia theobromae were qualitatively characterized by ultraviolet-visible (UV) spectrophotometer, elemental analysis (EA), Fourier transform infrared spectrometer (FTIR), nuclear magnetic resonance (NMR), electron paramagnetic resonance (EPR) and ultra-performance liquid chromatography-mass spectrometry (UPLC-MS). The results showed that the secreted melanin contained many functional groups such as hydroxy groups, alkanes and aromatic rings, which belonged to benzoquinone structure and aliphatic structure. The melanin secreted by Lasiodiplodia theobromae can be identified as a type of allomelanin. This research work is expected to provide a reference for the application of melanin in various fields in the future.

The mechanical properties of graphene oxide (GO) during tensile fracture were studied using molecular dynamics methods, and the influence of hydroxyl and epoxy groups on the mechanical properties of GO was explored. In addition, the changes in mechanical properties of GO under different temperatures and strain rates were studied to gain a deeper understanding of its mechanical behavior. The results indicate that hydroxyl and epoxy groups have a significant influence on the elastic modulus, ultimate stress, and ultimate strain of GO. The presence of hydroxyl and epoxy groups can alter the molecular structure of GO, thereby affecting its ultimate stress and strain. When the number of hydroxyl groups is 16 and the number of epoxy groups is 20, the ultimate stress decreases by about 31% and the elastic modulus decreases by about 20%. The variation of elastic modulus, ultimate stress, and ultimate strain of GO with temperature was studied at three temperatures: 300K, 500K, and 800K. As the temperature increases, the amplitude of atomic vibration increases and internal defects and cracks in GO continue to form and expand. At the same time, its coefficient of thermal expansion also increases, causing deformation and loosening of the crystal structure, resulting in a decrease of about 10% in the ultimate stress of GO, and a slight decrease in the ultimate strain and elastic modulus. Finally, the influence of different strain rates on the mechanical properties of GO was studied. As the strain rate increases, the intermolecular interactions within GO are rapidly altered, and the previously loose structure gradually becomes tightly ordered, resulting in an increasing trend in the elastic modulus, ultimate stress, and ultimate strain of GO.