The use of nanodiamonds in the seeding of CVD diamond and in heterogeneous catalysis

• Type: Article in International Conference Proceedings Book
• Date: 2018

Authors

Buijnsters, JG (Author) Other; Sónia Carabineiro (Author) FEUP; Silva, Adrian (Author) FEUP; Pastrana-Martínez, L.M. (Author) Other; Morales Torres, S (Author) Other; Joaquim Luís Faria (Author) FEUP; Figueiredo, JL (Author) Other

Conference proceedings International

Title: 2015 1st Workshop on Nanotechnology in Instrumentation and Measurement, NANOFIM 2015

Pages: 163-167

1st Workshop on Nanotechnology in Instrumentation and Measurement, NANOFIM 2015

24 July 2015 through 25 July 2015

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Other information

Authenticus ID: P-00P-HTQ

DOI: 10.1109/nanofim.2015.8425346

Abstract (EN): In this work, the use of nanodiamonds (NDs; 2-10 nm) in the seeding of diamond films grown by chemical vapor deposition (CVD) and in the synthesis of composite TiO2-nanodiamond photocatalysts is discussed. First, enhanced growth of faceted, nanocrystalline diamond (NCD) films by hot filament CVD at moderate substrate temperature (650°C) and carbon-lean gas chemistry (1.0% CH4 in H2) is demonstrated. The enhancement of diamond nucleation and growth on Si substrates is achieved by using a sputter deposition of different metallic (Cr, Nb, Ti, V, and W) nanolayers and an ultrasonic seeding with NDs. We conclude that the kinetics of diamond nucleation in the NCD film growth is determined by the number density of NDs embedded on the nanorough metallic surfaces after ultrasonic pretreatment and by the specific surface chemistry (i.e., carbon diffusivity and carburization) during diamond growth. Second., the synthesis and application of composites based on microdiamonds and NDs for the photocatalytic degradation of diphenhydramine pharmaceutical water pollutant is demonstrated. Micro- A nd nanodiamond powders were combined with TiO2, varying the carbon phase content and tested as composite photocatalysts under near UV-Vis irradiation. The thus prepared composites exhibited higher photocatalytic activity than the respective bare materials. Best photocatalytic performance was observed in the case of using composites with 15 wt.% of NDs oxidized in air at 703 K. © 2015 IEEE.

Language: English

Type (Professor's evaluation): Scientific