نشریه تحقیقات در علوم مهندسی سطح و نانو مواد
پیاپی 1 (بهار 1401)

In this short review study, the various methods used in surface modification of tin sulfide (SnS) nanostructures as novel applications are investigated. Surface modification is one of the effective methods for engineering the physical and chemical properties of semiconductor nanostructures for use in various applications. Surface modification of nanomaterials can be an important approach to increase their performance and efficiency due to the fact that many of the observed properties are due to their microscopic surface properties. Therefore, by studying the reports, the methods of cold plasma, inert and effective gases, using shell coating, adding dopants, and using the buffering layers that have been reported, are studied and reviewed. The focus of this study is on the effect of this modification on physical properties including crystal lattice, morphological, optical, electrical, and optoelectronic properties. Finally, conclusions and perspectives for the future of this field of research for surface modification of the SnS nanostructures are presented.

ASTM A517 Gr. B steel plates are a group of structured steels quench-tempered with a combination of suitable mechanical properties. The most important of these properties are the high yield strength, weldability and good toughness in low temperatures. Using these high strength steels causes decreasing cost and increase in efficiency. In this paper optimized tempering temperature and time is studied to achieve to proper mechanical properties in ASTM A517 Gr. B steel plate. For this purpose, nine rolled plates from one melt are tempered after quenching process in three temperatures of 630, 640 and 650 oC for 67,77 and 87 minutes. Results of the mechanical tests on the plates showed that increasing temperature and time of tempering causes decreasing of yield strength and tensile strength, decreasing hardness and increasing of strength against impact. Results also show that sensitivity of changing impact strength is more than temperature term.

In this study, iron-based alloy with Fe65B15Si10Ti5Al5 was prepared by mechanical alloying method . The effect of nickel content on its microstructure with 200 hours of milling was investigated. In this study X-ray diffraction and scanning electron microscopy equipped with chemical composition analyzer. Addition of nickel in the Fe65Ti5Al5B15Si10 alloy system and its increase reduced the intensity of all peaks, their broading and also the shift of peaks to lower angles. This indicates a decrease in the size of iron-alpha phase crystals and an increase in lattice strain due to an increase in nicke elmentl. Also, an increase in nickel reduced the particle size due to milling at the same hours of alloying. 

In this study, copper oxide has been successfully used as a good and inexpensive adsorbent to remove erythrosine and carmosine red dyes from several aqueous solutions. The effect of various parameters such as pH, dye concentration, adsorbent amount, contact time and temperature on the removal process was investigated. The isothermal adsorption data can be interpreted with the Langmuir and Freundlich isotherm models. Values higher than 43.103 K and 10.162 mg / L for erythrosine and red carmosine indicate that copper oxide has a greater affinity for dyes than other adsorbents 

The use of metal oxide nanostructures as an active material in the photocatalytic process is one of the proposed solutions for the treatment of drinking water and industrial wastewater. In this study, as an inexpensive metal oxide, zinc oxide nanorods were synthesized using a simple sol-gel method in egg white medium. Samples were prepared at an optimum temperature of 600 ° C for two periods of 3 and 5 hours to investigate the structural and morphological changes caused by the change in curing time. The samples were characterized by XRD, FESEM, UV-vis, PL measurements. The use of egg white medium caused the control of particle morphology and the production of structural oxygen vacancy defects which were confirmed by FESEM and PL tests, respectively. The photocatalyst test using methylene blue dye also confirmed the positive effect of one-dimensional morphology of nanostructures and the production of structural defects on increasing the photocatalytic efficiency of zinc oxide nanorods, which can be a good option for use in the manufacture of solar water filters and wastewater treatment.

In this paper, Structural, optical and photocatalytic properties of bismuth vanadate nanorods were studied. The bismuth vanadate (BiVO4) nanorods were made by thermal method in the presence of PEG (Polyethylene glycol) soft template. To study the nanorods, the X-ray diffraction analysis (XRD), field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDS) and ultraviolet– visible spectroscopy (UV-Vis) were used. The X-ray diffraction pattern were indicated that the nanorods have a monoclinic structure and the results of XRD and EDS analysis showed that there did not any impurity element in nanorods. From the FESEM image, it was found that the average diameter and length of the nanorods are 37 and 439 nm, respectively. The UV-Vis analysis showed that the optical band gap of bismuth vanadate nanorods is 2.22 eV, which is in the visible light range. The photocatalytic activity of nanorods were evaluated by photodegradation of Congo red under visible light irradiation. According to the results of this research, bismuth vanadate nanorods with monoclinic structure is a good choice for the degradation of organic matter with sunlight.