Open Access

Review

Article ID: 2136

Thermoelectric materials—Challenges, approaches and classes

by N. Karthikeyan, C. Prabhakaran, R. Akilan

Materials Technology Reports, Vol.2, No.2, 2024; 73 Views

Thermoelectric (TE) materials have gained significant attention in recent days for their ability to convert waste heat energy into electrical energy. Numerous advances in new and a unique thermoelectric materials have been developed during the last decades due to their ease of device fabrication technique and technology. Thermoelectric research has become a hotspot in materials science over the recent years due to its promising global necessity in energy generation, energy conservation and subsequent utilization. Here this article seeks to highlight some of the recent advances in thermoelectric research such as criteria for ideal TE materials, various strategies that are in practice to improve TE performance and different methodologies adopted in the preparation of TE-based materials. This article also highlights some of the explored state-of-art materials in thermoelectric research to layout a grid for future purposes.

Open Access

Perspective

Article ID: 2007

Graphene—A hello and goodbye

by Ayesha Kausar

Materials Technology Reports, Vol.2, No.2, 2024; 56 Views

After years of research, it can be stated that graphene was an initial game changer and jack of all trades in the world of nanotechnology, owing to innumerable structural/physical characteristics and mammoth range of hi-tech applications. Undoubtedly, since the discovery of graphene, it almost ruled all possible nanotechnological fields, from electronics/energy—to—defense/transportation/civil—to—biomedical. Nevertheless, this statement remained no longer valid after the discovery of more erudite nanostructures, like fullerene, quantum dots, and similar nanoparticles. Reasons for today’s technology turns towards tiny symmetrical nanoparticles seem to be the limitations/hinderance for integrating graphene into energy/semiconducting/photonic devices, and subsequent commercialization over past two decades. In this novel perspective report, therefore, we first time critically analyzed the nanotechnological shifts from graphene, yet despite its early promises, towards proficient zero dimensional entities.

Open Access

Article

Article ID: 1762

Potentiality of alginate-yeast biosorbent for biogas purification

by Norli Ismail, Bilhate Chala, Joachim Mueller, Hans Oechsner

Materials Technology Reports, Vol.2, No.2, 2024; 4217 Views

The paper discussed the current research on the applicability of biosorbents for the purification of biogas, particularly the decrease of H 2 S by using encapsulated or embedded biological biomass. This study investigated the potential of alginate-yeast biosorbent (AlgY) for biogas purification, focusing on hydrogen sulfide (H 2 S) removal. A biogas column test was conducted to compare the biosorption efficiency of AlgY and pure alginate beads. Using Response Surface Methodology (RSM), the effects of column length, acquisition time, and biosorbent type were evaluated for CH 4 , CO 2 , and H 2 S removal. Results depicted significant H 2 S reduction, with AlgY achieving a p -value of < 0.0001 and a high correlation coefficient ( R 2 = 0.9518). The relatively high correlation coefficient ( R 2 ) of the tested quadratic model of all the responses were recorded ( R 2 ; 0.5560, 0.5048, and 0.9518 for CH 4 , CO 2 , and H 2 S respectively). According to the studies’ preliminary findings, the type of biosorbent has a significant role in determining the biosorption effectiveness. The ANOVA of model terms depicted a significant p -value ( p < 0.05) indicated a potential alginate-yeast (AlgY) biosorbent for H 2 S purification or reduction.

Open Access

Article

Article ID: 1699

Preparation and characterization of CuBO2-based photocatalysts and doped variants

by Soheila Azordeh, Mehdi Asadi, Abdolali Alemi

Materials Technology Reports, Vol.2, No.2, 2024; 4171 Views

An eco-friendly CuBO 2 -based photocatalyst has been doped by a lanthanide for the first time. Gd 3+ and Gd 3+ /Bi 3+ -doped CuBO 2 are synthesized by the hydrothermal method to study their magnetic properties. Then they are analyzed by XRD, UV-Vis, SEM, and VSM. The maximum amount of doping is x= 0 − 1.5% in Cu 1 – 3x Gd 3x BO 2 and Cu 1 – 3x Bi 3x/2 Gd 3x/2 BO 2 formulas as they are analyzed in XRD. For concentrations higher than x = 2%, the additional peak indicates that doping is incomplete. The XRD pattern of CuBO2 confirms that its crystal structure is a hexagonal one with the R3 ̅m space group. According to UV-Vis analysis, the bandgap energies are 2.711, 2.753, and 2.765 for CuBO 2 and doped systems. Additionally, the morphology of particle sizes is confirmed according to SEM images. Meanwhile, the magnetic properties of synthesized material are studied by VSM, and the doped compound exhibited higher magnetic properties than CuBO 2 , which is associated with the exchange interaction of electron and d spins in Gd 3+ and Bi 3+ . The study aims to provide insights into the magnetic properties of lanthanide-doped CuBO 2 -based photocatalysts, potentially paving the way for developing improved magnetic materials for various applications.

Open Access

Article

Article ID: 1813

Study on the influence of aluminium nitride particulates on the dry sliding wear behavior and mechanical properties of aluminium 6061 alloy developed using stir casting method

by Raghavendra Subramanya, Manjunatha Kuntanahalli Narayanappa, Nagesh Devareddy, Madusudhana Shettykothanuru Vemanna, Ravikumar Mukundaiah, Chandra Shekar Anjinappa, Thyagaraj Narasapura Rajanna, Arun Kumar Rudrappa

Materials Technology Reports, Vol.2, No.2, 2024; 3961 Views

Aluminium matrix composites (AMCs) reinforced with hard ceramic particles is currently being widely used as a composite material for a range of industrial and technical applications. In the current study, melt stirring was employed to incorporate Aluminium nitride (AlN) particulates into the aluminium 6061 alloy. In this study AlN particles in different proportions 2%, 4%, 6%, and 8% wt were used with Al6061 alloy. Scanning electron microscopy (SEM) and x-ray diffraction were used to characterise the stir cast composites and the base alloy. SEM analysis confirmed the uniform distribution of AlN particles within the Al matrix. The impact of AlN concentrations on the mechanical properties of Al6061 matrix composites was investigated. Pin on disc machines were utilised to examine the dry sliding wear properties of the composites that were manufactured. The presence of very hard AlN elements in the Al6061 matrix alloy significantly improved the mechanical and wear characteristics of the AMCs. As compared to the Al6061 base alloy, the test results showed that the Al6061 with 8% weight percentage AlN composites had better wear resistance and hardness yield strength and the alloy with 2% AlN showed highest tensile strength of 368 MPa. The good interfacial adhesion between fillers and matrix prevents cracking and allows for effective load transmission to the reinforcing phase. This is mainly because AlN is a highly strong and stiff material, and its incorporation gives strong reinforcement as well as increased tensile, flexural, and hardness strength to the composite. This enhancement in mechanical properties suggests potential applications in high-wear industries such as automotive and aerospace.

Open Access

Review

Article ID: 1879

Energy systems and green sourced nanomaterials—A today’s outlook

by Ayesha Kausar

Materials Technology Reports, Vol.2, No.2, 2024; 3381 Views

Owing to current growing demands of environmental friendly energy devices, innumerable green materials/nanomaterials have been applied to design the desired high tech devices. Amongst energy devices, supercapacitors have been ranked distinctively for efficient energy storage competence. Principally, green nanocomposites derived from green or ecological polymers and green nanoparticles have been scrutinized for supercapacitor components. Concerning this, current review has been planned to sketch the energy storage application of green nanocomposites, predominantly for supercapacitors. In this concern, mostly synthetic green polymers (such as polyaniline, polypyrrole, etc.) and their blends with natural polymers (like chitosan) having fine biodegradability, non-toxicity, low cost, and superior device end performance have been found as the noteworthy materials. Additionally, green nanofillers like carbon nanoparticles (carbon nanotube, graphene, etc.) and metal nanoparticles have been processed with green polymers via ecological techniques, like in situ, solution, sonication, mixing, hydrothermal, exfoliation, reduction, etc., to form the anticipated energy device components. In consequence, the designed ecological nanocomposites expectedly had the advantages of low price/weight, superior mechanical/heat resilience, electron transference, capacitance, power/charge density, charge-discharge, sustainability as well as environmentally friendliness for energy related methodological systems. Incidentally, the design and performance challenges towards the application of ecological nanocomposites in energy storage devices have been conversed.