Microstructural, structural and optical properties of nanoparticles of PbO-CrO3 pigment synthesized by a soft route

Abstract

PbCrO4 and Pb2CrO5 particles were synthesized by the polymeric precursor method. Structural and microstructural properties of the particles were characterized by scanning electron microscopy with field emission gun, X-ray diffraction, and Raman spectroscopy techniques. The diffuse reflectance technique was employed to study the optical properties in the 400-700 nm range. The optical bandgap of the samples was obtained indirectly. Colorimetric coordinates L*, a*, b* were calculated for the pigment powders as a function of the heat treatment (400-700 ºC). The powders displayed colors ranging from green to red. X-ray diffraction patterns showed the presence of monoclinic PbCrO4 phase in green samples, while red powders had a monoclinic Pb2CrO5 phase structure. The Raman spectra of the PbCrO4 and Pb2CrO5 powders were in good agreement with those reported in the literature. The synthesized compounds can be used as green and red pigments with high thermal stability.

Visible Light Photoelectrochemical Properties of PbCrO4, Pb2CrO5, and Pb5CrO8

“…Using eq , the size of the optical band gap is obtained at the x -intercept of the extrapolated linear region of the Tauc plot, or (α h ν) 1/ m vs h ν. Tauc plots of PbCrO 4 , Pb 2 CrO 5 , and Pb 5 CrO 8 shown in the Figure inset exhibit broad linear regions with m = 1/2, indicating a direct band gap with band gap sizes of 2.38, 2.25, and 2.07 eV for PbCrO 4 , Pb 2 CrO 5 , and Pb 5 CrO 8 , respectively. The resulting band gap nature and the change in the gap size were consistent with those in previous reports …”

Thermal Stability of Inorganic Pigments Synthesized from Galvanic Sludge

“…The particle sizes may reach up to 8μm, highlighting the positive temperature effect on the grain growth rate. Araújo et al has evidence a high rate of the granule growth, hence a good reactivity of lead chromate, by thermal treatment up to 700°C [21]. a b Figure 4.…”