Materials Science for Energy Technologies最新文献

Recent concerns regarding climate change and rising energy costs have dramatically increased interest in using alternative energies, especially biomass energy which is carbon neutral. Hemp is among the fastest-growing plants with unique fiber characteristics. The objective of this study was to investigate the physical and chemical properties of hemp stalks of seven different clones and to assess their feasibility as a sustainable bioenergy resource. Seven clones (KU03, KU18, KU27, KU45, KU49, RPF1, and RPF2) of four-month-old hemp (Cannabis sativa) were used in this work. Physical properties, volatile content, fixed carbon, ash content, calorific value, chemical composition, ash composition, and metal element of the samples were investigated. The results revealed that hemp stalk had desirable fuel characteristics with high volatile substance, high heating value, low ash content, very low nitrogen content, and non-detectable sulfur. Selecting well-adapted clones and appropriate technology which can convert the hemp stalks to suitable bioenergy forms are important aspects of bioresource management. Based on our findings, some selected hemp clone biomass possessed excellent characteristics and great potential to be used as raw material for bioenergy production.

The present study deals with developing biochar from the waste biomass using slow pyrolysis at dynamic temperatures (400, 600, and 800 °C) and holding times (30, 45, and 60 min). The produced biochars were characterized by their thermal, physical, and chemical properties. The biomass characterization confirmed its candidacy for being used as a biochar feedstock. An XRF study of ash content confirmed that biomass has a lower possibility of slagging and fouling issues. A kinetic study of biomass confirmed that activation energy increased substantially (34.37–90.34 and 22.74–63.92 kJ mol⁻¹ for MWS and CNW, respectively) by varying the reaction order. The outcomes of the pyrolysis process revealed that elevating the pyrolysis temperature from 400 to 800 °C resulted in a decrease in the yield of biochar, accompanied by an increase in its carbon content. XRD study of biochar established that rising pyrolysis temperature caused a change in the mineral content of biochar. HHV and bulk density of biochar were found to be increased by increasing pyrolysis temperature from 400–800 °C. Moreover, it was observed that BET surface area and Zeta potential increased as the pyrolysis temperature rose from 400–800 °C. FE-SEM study of biochar, established by increasing temperature from 400–800 °C, accelerated the volatilization activity and caused a considerable surface modification in the resulting biochar. Overall, biochar displayed various mineralogical compositions, surface alteration, high thermal stability, carbon content, and pH, making them appropriate for strengthening the procedures of different industrial applications.

Organic pollutants such as 4-nitrophenol (4-NP) pose serious environmental extortions due to their chemical stability for which efficient catalytic materials are indispensable in treating them. In this regard, the present work involves the synthesis of two different types of ferrites (NiFe₂O₄, and CuFe₂O₄), and a combination of Ni_xCu_xFe₂O₄ with various ratios that systemically work as efficient photocatalysts without any additional reducing agents is reported. The structural, and morphological properties of NiFe₂O₄, CuFe₂O₄, and NiCuFe₂O₄ were characterized by XRD, FT-IR, SEM, and HRTEM techniques. Then, the catalytic role of individual ferrite catalysts was evaluated towards catalytic reduction of 4-NP under visible light. The progress dye reduction was examined via UV–vis spectrophotometry. The effect of various concentrations, and reduction time were investigated. The kinetic rate constants determined for NiFe₂O₄, CuFe₂O₄, and Ni_xCu_xFe₂O₄ revealed that Ni and Cu in bimetallic ferrites promoted the reduction reaction under visible light. The results demonstrated that the photo-reduction efficiency of the Ni_0.7Cu_0.3Fe₂O₄ catalyst over 4-NP (conc. 10 ppm) to 4-AP was determined as 82 % under 120 miniutes with good recyclability up to six cycles. The mechanism of photocatalytic reduction of ferrites without the use of a reducing agent was studied. Such facile and productive ferrite materials could be employed as efficient photocatalysts for the reduction of toxic organic contaminants in environmental treatment.

Absorber thickness is one among keys parameters that can have significant effects on the performance of the solar cell. An appropriate absorber thickness should be chosen to optimize the performance of the cell.The main objective of this work is to offer a perovskite solar cell with high efficiency using a suitable thickness of the active layer. Therefore, this study focuses on the optimization of the solar cell thickness, which can also be achieved by using simulation with SCAPS-1D, to predict the performance of the cell at different thicknesses. In this case, the four main parameters; the short circuit current density, the open-circuit voltage, fill factor and power of conversion efficiency, were extracted and analyzed from I–V characteristics at different thicknesses. In addition, the complex impedance data were also generated by using simulation with SCAPS-1D. To the best of our knowledge, this approach was not used before for many works carried out by SCAPS-1D simulation; where these studies were limited to I-V characteristics. This novel approach to investigating the electrical response of this solar cell concerning thickness involves the integration of complex impedance and modulus functions. This integration enables us to discern the respective contributions of ionic diffusion and recombination processes, through our deconvolution procedure, the results obtained indicate the absorber layer thickness increases, the diffusion and recombination processes are affected differently, subsequently influencing the overall performance of the solar cell. Both methodologies employed in this study consistently identified the maximum efficiency at an optimal thickness of 700 nm.

Different polylactic acid (PLA) thin films containing clarithromycin and a number of metal oxide nanoparticles (magnesium, titanium, zinc, and nickel) dioxides were created. Low dosages of metal oxides (0.01% by weight) and clarithromycin (0.5% by weight) were used to make transparent films. The role of metal oxide nanoparticles and clarithromycin as UV blockers for PLA photodegradation was looked at. The durability of polymeric materials is improved more by clarithromycin in combination with metal oxides than by clarithromycin alone in PLA films. An analysis of the weight loss, surface morphology, and changes in infrared spectra of irradiated polymeric blends revealed that nickel oxide and clarithromycin together function as effective UV blockers and offer PLA a high degree of protection. Nickel oxide nanoparticles were the best addition for PLA stability. Highly alkaline metal oxides are present. Contrarily, the heteroatom and aromatic nature of clarithromycin enables it to absorb damaging radiation and function as an ultraviolet absorption. Thus, the adaptability of PLA to photodegradation was significantly improved by using a mixture of metal oxide nanoparticles and clarithromycin.

Titanium dioxide (TiO₂) nanoparticles are commonly used as photoanode materials in dye-sensitized solar cells (DSSC). The structure of TiO₂ can be modified by doping to enhance its optical and electrical performance. The modification carried out in this research was by providing Ag doping on TiO₂. Silver (Ag) added to TiO₂ is convinced to reduce the recombination and increase the energy level of the photo-excited electrons from the TiO₂ conduction band. Ag-doped TiO₂ was carried out by a simple mixing method. The microstructure of Ag-doped TiO₂ was successfully characterized by XRD and SEM. The absorbance of the Ag-doped TiO₂ thin films was measured by UV–Vis spectroscopy, confirming the optimum energy gap of 3.09 eV and resulting in the best PCE of 6.31 %.

This paper deals with the synthesis and properties of new ternary mixed Cd1-xBexTe (cadmium beryllium telluride) crystal-based electrodes for photovoltaic cells which is a modified version of dye- sensitized solar cells. We determined the thermal stability and photovoltaic performance of the obtained devices. Cd1-xBexTe crystals are grown using the Bridgman technique at high temperatures and pressure for different compositions. Using the modified doctor blade method, we fabricated dye-sensitized solar cells (DSSC) using Cd1-xBexTe-based film as working electrodes. The mixed crystals with the highest beryllium content (10 %) and the lowest (1 %) are used. At the same time, the counter electrode and polymer electrolytes are common. Comparative studies with standard DSSC are also undertaken to compare the stability and charge mechanism. As prepared, DSSC using ternary Cd1-xBexTe showed efficiency as high as 3.11 % at 1 sun condition. The life span measurement indicated promising results, and DSSC is stable up to 720 h with a reasonable decrease in fill factor from 84 to 55.

With the help of a hydrothermal process, we were able to prepare vertically layered MoS₂ nanoflakes that were rooted to TiO₂ modified. MoS₂ nanoflakes and TiO₂ contribute significantly to the strong XRD peaks and μ-Raman spectroscopy, and this phenomenon may also be explained by the unique structure of vertically stacked MoS₂ nanoflakes on TiO₂ that has many exposed edges and large surfaces as well as high electron transfer rates between TiO₂ and MoS₂. As can be clearly seen, there are no noticeable changes in the self-photodegradation of MB under visible light interaction (VLI), and the MoS₂ doped TiO₂ photocatalyst displays ∼ 90 % degradation efficiency. By, measuring photoelectrochemically, charge carriers are separated efficiently. These experiments illustrate the transient photocurrent response of the MoS₂ doped TiO₂ photocatalyst while cycling between three on/off cycles. As a result of a low recombination rate of the photoexcited charge carriers, the MoS₂ doped TiO₂ photocatalyst displays superior photocurrent response. In other words, a lower charge transfer resistance results in a faster transfer of charge between the surfaces.

This research aims to provide an efficient and cost-effective renewable energy supply. It assesses the potential for photovoltaic (PV) and hydro energy in Pirthala, Haryana, India, using HOMER Pro® v3.14.2. A Hybrid renewable energy system (HRES) can continuously power 855 homes. The optimal HRES configuration comprises well-optimized PV modules, hydro turbines, converters, and batteries. The top four configurations were selected based on criteria such as net present cost (NPC) and cost of energy production (COE). The most effective HRES configuration involves a 3461-kW solar array, a 98.1 kW hydro turbine, 304 lithium-ion batteries of 100 kWh, and a 2785-kW converter, achieving a 100 % integration of renewable energy. This ideal HRES was thoroughly assessed regarding economic, technical, and renewable energy considerations. The results and the optimized HRES configuration can serve as a valuable reference for similar initiatives in rural areas, contributing to adopting renewable energy sources and enhancing energy access and reliability.