Co-precipitation synthesis, humidity sensing and photoluminescence properties of nanocrystalline Co 2+ substituted zinc(II)molybdate (Zn 1–x Co x MoO 4 ; x = 0, 0.3, 0.5, 0.7, 1)

Autor: A. Dayalan, K.S. Nagaraja, V. Jeseentharani
Rok vydání: 2017
Předmět:
Zdroj: Solid State Sciences. 67:46-58
ISSN: 1293-2558
DOI: 10.1016/j.solidstatesciences.2017.02.008
Popis: Zinc-cobalt molybdate composites (Zn1–xCoxMoO4; x = 0, 0.3, 0.5, 0.7, 1) were synthesised by a simple co-precipitation method and characterised by thermogravimetric/differential thermal analysis (TG/DTA), Fourier transform-infrared (FT-IR), Fourier transform Raman (FT-Raman) spectroscopy, X-ray diffraction spectroscopy (XRD), scanning electron microscopy (SEM/EDAX) and transmission electron microscopy (TEM). The surface area was calculated by BET analysis in the adsorption/desorption isotherm. The humidity sensing properties of zinc-cobalt molybdates were tested by dc electrical measurements at different relative humidity environments (RH = 5–98%). The electrical resistance of the composites linearly decreases and the maximum sensitivity of 3672 ± 110 was observed for the Zn0.3Co0.7MoO4 (ZnCM-4) composite towards humidity, which is calculated by the relation Sf = R5%/R98%, where the response time is 200 s and the recovery time is 100 s. Photoluminescence (PL) measurement at the room temperature of ZnM-1 composite exhibited a blue emission peak at 475 nm (λem) when excited at a wavelength (λex) of 430 nm. During Co2+ substitution in Zn2+ matrix, a green and red emission peak was observed when excited at a wavelength (λex) of 520 nm.
Databáze: OpenAIRE
Externí odkaz: