In this paper, undoped TiO2 and Ag-Nd-codoped TiO2 nanocomposites with different molar ratios of dopants were synthesized by the sol-gel method using starch as a natural additive. Structures were investigated by FT-IR and UV–Vis spectroscopy, SEM, and XRD methods. Moreover, the direct band gap was calculated by Tauc's approach. Furthermore, photocatalytic activity of all samples were investigated under UV irradiation in an aqueous medium. Compared with undoped TiO2, the band gap of the Ag-Nd -TiO2 samples decreases and depends on the content of dopants. In addition, photocatalytic activity improves in the presence of appropriate amount (1.5 mol%) of Ag and Nd as dopants. تفاصيل المقالة

In this work the Origanum vulgare leaf extract was used to green synthesis of Ag nanoparticles (NPs) supported on Hazelnut shell as an environmentally benign support. The Ag NPs/Hazelnut shell as an effective catalyst was prepared through reduction of Ag+ ions using Origanum vulgare leaf extract as the reducing and capping agent and Ag NPs immobilization on Hazelnut shell surface in the absence of any stabilizer or surfactant. According to FT-IR analysis, the hydroxyl groups of phenolics in Origanum vulgare leaf extract as bio-reductant agents are directly responsible for the reduction of Ag+ ions and formation of Ag NPs. The as-prepared catalyst was characterized by Fourier transform infrared (FT-IR) and UV-Vis spectroscopy, field emission scanning electron microscopy (FESEM) equipped with an energy dispersive X-ray spectroscopy (EDS), X-ray diffraction analysis (XRD) and transmittance electron microscopy (TEM). The synthesized catalyst was used in the reduction of Methyl Orange (MO), and Congo Red (CR) at room temperature. The Ag/Hazelnut shell showed excellent catalytic activity in the reduction of these organic dyes. In addition, it was found that Ag/Hazelnut shell can be recovered and reused several times without significant loss of catalytic activity. تفاصيل المقالة

In this paper, undopedZnO and Co-ZnOnano structureswith different molar ratio of Cobalt have been synthesized by the sonochemical method. Structure have been characterized by Fourier Transform (FTIR) and UV–Vis spectroscopy,Scanning Electron Microscopy (SEM), Energy Dispersive Analytical X-Ray (EDAX), and X-Ray Diffraction (XRD) methods. Moreover, the direct band gap has been calculated by Tauc’s approach.Moreover, mean crystal size has been estimated by Scherrerequaton. Furthermore, photocatalytic activity for all samples has been investigated under UV irradiation in an aqueous medium. Compared with pure ZnO, the band gap of the Co-ZnOhas been shown decrease and it is dependent on the content of dopants. Also, photocatalytic activity improves in the presence of cobalt dopant. تفاصيل المقالة

In the present study, Pb-ZnO, Fe-ZnO, Cd-ZnO and Pb-Fe-Cd-ZnO nanoparticles were synthesized by the sonochemical method and those structural and optical properties were investigated by Fourier Transform Infrared spectroscopy (FTIR), UV-Vis spectroscopy, Field Emission Scanning Electron Microscopy (FE-SEM) and X-Ray Diffraction (XRD). Average crystallite size obtained was 60 nm. Moreover, the direct band gap has been calculated using Tauc's approach. Compared with pure ZnO, the band gap of the doped-ZnO NPs is smaller and it depends on the type of dopants. In addition, photocatalytic activity of all samples has been investigated by the degradation of congo red (CR) dye under UV irradiation in an aqueous medium. In the presence of ZnO NPs photocatalytic degradation of 35% was obtained for 180 min. But Pb-ZnO, Fe-ZnO, Cd-ZnO and Pb-Fe-Cd-ZnO have shown the degradation of 45, 57, 65 and 80% respectively; they have the faster decolorization as compared with the ZnO NPs. Moreover, the photocatalyst could be reused for five times without remarkable loss of its activity. تفاصيل المقالة

در این پژوهش، عصاره گیاه گل آرونه برای سنتز سبز نانوذرات نقره (AgNPs) بر بستر پوست هسته هلو به‌عنوان یک بستر مفید و سازگاربامحیط‌زیست استفاده شده است. نانوذرات نقره جایگزین شده بر پوست هسته هلو، (AgNPs/P.K.shell)، به‌عنوان یک کاتالیست مؤثر با کاهش یون‌های +Ag به کمک عصاره گیاه گل آرونه و جایگزینی آن‌ها بر بستر پوست هسته هلو سنتز شد. بر اساس نتایج FT-IR وجود گروه‌های هیدروکسیل ترکیبات فنلی در عصاره گیاه گل آرونه، کاهش یون‌های +Ag را توجیه می‌کند. همچنین، کاتالیست سنتز شده با روش‌های متفاوت از جمله طیف‌سنجی مرئی-فرابنفش (UV-Vis)، طیف‌سنجی فروسرخ تبدیل فوریه (FT-IR)، میکروسکوپ الکترونی روبشی گسیل میدانی (FE-SEM)، طیف‌سنجی تفکیک انرژی (EDS)، پراش پرتو ایکس (XRD) و میکروسکوپ الکترونی عبوری (TEM) بررسی شد. افزون بر آن، کاتالیست سنتز شده برای کاهش متیلن بلو (MB) و ردآمینBا(RhB) به‌کار گرفته شد. نتایج نشان داد که کاتالیست AgNPs/P.K.shell سنتز شده فعالیت کاتالیستی بسیار خوبی در تخریب رنگ‌های آلی استفاده‌شده دارد. نتایج نشان داد که کاتالیست سنتز شده قابلیت بازیابی و استفاده دوباره را برای چندین مرتبه بدون کاهش چشمگیر در فعالیت فوتوکاتالیستی دارد. تفاصيل المقالة