مقاله انگلیسی فعالیت نور قابل مشاهده از فوتوکاتالیست های لایه نئوبات نیتروژنی توسط NH3-نیتریدی با شار KCl

26 شهریور 1397 | 11:07

مقاله انگلیسی فعالیت نور قابل مشاهده از فوتوکاتالیست های لایه نئوبات نیتروژنی توسط NH3-نیتریدی با شار KCl
عنوان فارسی مقاله: فعالیت نور قابل مشاهده از فوتوکاتالیست های لایه نئوبات نیتروژنی توسط NH3-نیتریدی با شار KCl
عنوان انگلیسی مقاله: Improved visible-light activity of nitrogen-doped layered niobate photocatalysts by NH3-nitridation with KCl flux
مجله/کنفرانس: Applied Catalysis B: Environmental
رشته های تحصیلی مرتبط: مهندسی شیمی
گرایش های تحصیلی مرتبط: ترموسینیتیك و كاتالیست
کلمات کلیدی انگلیسی: Nitrogen doping; Layered metal oxide; Visible light; Photocatalyst; Flux
نوع نگارش مقاله: پژوهشی - research
نمایه: scopus - master journals - JCR
DOI: doi.org/10.1016/j.apcatb.2018.03.007
ناشر: الزویر - Elsevier
نوع ارائه مقاله: ژورنالی
نوع مقاله: ISI
سال انتشار مقاله: 2018
ایمپکت فاکتور(IF): 11.698(2017)
شاخص H_index: 188
SJR: 3.152
شناسه ISSN: 0926-3373
فرمت مقاله انگلیسی: PDF
تعداد صفحات مقاله انگلیسی: 21
کد محصول: EN106
فهرست انگلیسی مطالب
Abstract

Introduction

Experimental Section
-Catalyst preparation
-Characterization
-Photocatalytic reactions

Results and Discussion
-Characterization of N-doped KCa2Nan–3NbnO3n+1 samples
-Photocatalytic water oxidation and reduction over N-doped samples

Conclusion

References
نمونه متن انگلیسی
Abstract

In the present study, nitrogen doping into layered perovskite niobites, KCa2Nan–3NbnO3n+1 (n = 3 or 4), was attempted to enhance their response to visible light during photocatalytic water reduction and oxidation. Although conventional nitridation, i.e., heating in NH3 stream at a high temperature, produced black-colored samples due to the undesirable reduction of Nb5+ to Nb4+ (and/or Nb3+), the use of KCl flux with NH3 stream effectively prevented the reduction of Nb5+, resulting in yellow-colored samples that had a much lower concentration of reduced Nb species. The samples prepared with KCl flux exhibited stronger absorption (at λ = 350–550 nm) when compared to those prepared without KCl flux. This was due to the higher concentration of N3– anions, as confirmed by elemental analysis and the observed peak shift in XRD patterns. On the other hand, the absorption band with λ > 550 nm, which indicated the presence of reduced species or anion vacancies, were astonishingly smaller for the samples prepared with KCl than for those without KCl. This indicated that the formation of reduced Nb species was inhibited by KCl. XPS analysis also supported this effect. The use of KCl flux also prevented the problematic decrease in the concentration of potassium cations in the interlayer space during high-temperature treatment in NH3 flow. The samples prepared with KCl flux exhibited much higher O2 and H2 evolution rates under visible-light irradiation in the presence of an electron acceptor and a donor, respectively as compared to those prepared without KCl. This clear improvement in O2 and H2 evolution was probably due to the larger amount of doped nitrogen introduced and/or the suppressed formation of reduced Nb species.
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