Najran University

About: Najran University is a education organization based out in Najrān, Saudi Arabia. It is known for research contribution in the topics: Photocatalysis & Nanoparticle. The organization has 751 authors who have published 1809 publications receiving 28233 citations.

Enhanced Photocatalytic Activity of B, N-Codoped TiO2 by a New Molten Nitrate Process

Abstract: B, N-codoped titania mesoporous crystals were prepared by the sol-gel method followed by a molten nitrate process to modify the sample morphology. The composition, morphology and microstructure of the obtained samples were characterized by X-ray diffraction (XRD), X-ray photoemission spectroscope (XPS), Brunauer Emmett Teller (BET), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and selected area electron diffraction (SAED). Fourier Transform Infrared spectroscopy (FTIR) revealed weak complex vibrations between the Ti-O oxide species and the unsaturated sites (Ti3+) through the incorporation of hydroxyl groups, which was not observed in the bulk titania (B-N-TiO₂). The photocatalytic reactivity of boron-nitrogen codoped TiO₂ was examined for the removal of methylene blue (MB) under visible light irradiation. The nitrates treated B-doped TiO₂ exhibited better photocatalytic activity for dye degradation than that of B-doped TiO₂ and nitrates treated TiO₂. The best performance was obtained in the sample treated at a calcination temperature of 550 °C.

Hybrid ZnO/ZnS nanoforests as the electrode materials for high performance supercapacitor application

Abstract: Heterostructured ZnO/ZnS nanoforests are prepared through a simple two-step thermal evaporation method at 650 °C and 1300 °C in a tube furnace under the flow of argon gas, respectively. A metal catalyst (Au) to form a binary alloy has been used in the process. The as-obtained ZnO/ZnS products are characterized by using a series of techniques, including scanning electron microscopy (SEM), X-ray diffraction (XRD), energy dispersion X-ray spectroscopy (EDS), Raman spectroscopy and photoluminescence. A possible growth mechanism is temporarily proposed. The hybrid structures are also directly functionalized as supercapacitor (SC) electrodes without using any ancillary materials such as carbon black or binder. Results show that the as-synthesized ZnO/ZnS heterostructures exhibit a greatly reduced ultraviolet emission and dramatically enhanced green emission compared to pure ZnO nanorods. The SCs data demonstrate high specific capacitance of 217 mF cm−2 at 1 mA cm−2 and excellent cyclic performance with 82% capacity retention after 2000 cycles at a current density of 2.0 mA cm−2.

Nanoemulgel for Improved Topical Delivery of Retinyl Palmitate: Formulation Design and Stability Evaluation

Abstract: Retinyl palmitate is a vitamin A ester belonging to the family of endogenous natural retinoid and used to treat various skin disorders like acne, skin aging, wrinkles, and dark spots, as well as to protect against psoriasis. Despite the known therapeutic benefits of retinyl palmitate, the conventional topical delivery of retinyl palmitate commonly associated with adverse reactions such as skin irritation, redness, excessive peeling, and dryness. Therefore, the current study aims to encapsulate the retinyl palmitate in nanoemulsion then incorporate it into a hydrogel system to improve the topical delivery and stability. Low-energy emulsification method was used for the nano-encapsulation of retinyl palmitate. The phase behavior study was used for the investigation and the optimization of the formulation. The droplet size of the optimized nanoemulsion was in nano dimension (16.71 nm) with low polydispersity index (PdI) (0.015), negative zeta potential (-20.6 mV). It demonstrated the influence of vortexing on droplet size and PdI during nanoemulsion preparation. The retinyl palmitate loaded nanoemulgel delivery system exhibited significant improvement (p < 0.05) in skin permeability after topical application. Employment of the nano-encapsulation approach afterward dispersion into hydrogel system for the development of a topical delivery system of retinyl palmitate resulted in improvement in its UV and storage stability as well.